I have a new Marlin 336CB in 38-55.

I have read about the SAMMI ~30,000 CUP for the 38-55 Win.

I have also read about the ~50,000 CUP for the 375 Winchester.

I see that the 336 Marlin is chambered in BOTH 375 Win and 38-55 Win.

I know that there are older model rifles chambered in 38-55 Win and these older rifles may not have been designed to withstand 50,000 CUP.

I have read a few times where folks have stated they shoot 375 Win from their 38-55 Marlin 336.

I have talked with a gunsmith familiar with the 336 Marlin and was told the rifle is no different between the two chamberings.

I believe Marlin would default to the SAMMI (and legally safe) specification if I were to call them.

What is the consensus here, is it safe to shoot 375 Win ammunition in a new Marlin 336CB chambered for 38-55 Winchester??

I have read a few times where folks have stated they shoot 375 Win from their 38-55 Marlin 336.

There is a difference between the two chamberings. I have a .375 Winchester and my Father has a TC Encore in .38-55. We have shot both cartridges in the Encore with no indication of trouble.

To better understand why people get away with shooting the .375 in the older .38-55 rifles read Ken Waters Pet Loads article on the .375 - 1-79 and the Pet Loads-Update, 1-83. The .375 case is shorter by design. Pretty clever design thoughts went into this cartridge.
The Ken Waters article is pretty good. As I recall, he did just that, at least once.
Go ahead and shoot 375 factory ammo out of your 38-55 <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" /> <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" />...cause you're just another accident waiting to happen <img src="/ubbthreads/images/graemlins/frown.gif" alt="" /> <img src="/ubbthreads/images/graemlins/frown.gif" alt="" />! And when it does you'll be one of those who'll sue Marlin... <img src="/ubbthreads/images/graemlins/mad.gif" alt="" /> <img src="/ubbthreads/images/graemlins/mad.gif" alt="" />

GET YOUR HEAD OUTTA YOUR BUTT <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> AND READ A RE-LOADING MANUAL...
I'm not familiar with the 336CB, but if it's a full size 336 action I can't see any reason not to shoot the .375's through it. I'd ask over on the marlin site:


The 336 cb could be a slimmed down version of the 336 action or barrel or have some other change that would make it unsuitable. However the marlin .375 was built on a plain vanilla 336 action.


[Linked Image]
Go ahead and shoot 375 factory ammo out of your 38-55 <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" /> <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" />...cause you're just another accident waiting to happen <img src="/ubbthreads/images/graemlins/frown.gif" alt="" /> <img src="/ubbthreads/images/graemlins/frown.gif" alt="" />! And when it does you'll be one of those who'll sue Marlin... <img src="/ubbthreads/images/graemlins/mad.gif" alt="" /> <img src="/ubbthreads/images/graemlins/mad.gif" alt="" />

GET YOUR HEAD OUTTA YOUR BUTT <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> AND READ A RE-LOADING MANUAL...

So I guess your answer is:

I don't have any direct experience with this but have you read your reloading manual?

Thanks.. !

Yes, I've read my reloading manuals and many articles about the 38-55 Win and the new Marlin and Winchester rifles chambered in 38-55 Win. While the 38-55 chambering is old and there were many rifle chambered for it originally there are now many new rifles being chambered for 38-55 Win.

I'd pretty much agree that sticking a 375 Win round in a vintage Marlin 38-55 chambered rifle would be a bad idea I can find a good bit of information stating that the NEW MARLIN 336 rifles in 38-55 are no different in strength to the NEW MARLIN rifles chambered in 375 Win. I have dies and reloading supplies for the 38-55 and intend to test loads to maximum SAAMI and perhaps beyond!

I'd prefer replies from folks with direct experience and knowledge.
Even if it's safe why would you want to? There is plenty of hot 38-55 ammo available and it's got to be a lot easier to find than 375 ammo.
38-55 Ammo seems to be seasonal but where I am there seems to be a good deal of 375 Winchester ammo.

Also, the factory offerings of 38-55 (Winchester load) is pretty anemic (1300fps with a 255gr). The reload manuals show upwards of 1900fps with this bullet in the 38-55.

I intend to use this rifle for proper hunting, not cowboy plinking.

Factory 375 Win ammo should be in the 2200 fps range with a 220gr bulelt.
Dave you might want to check out the Buffalo Bore offerings for the 38-55. In "Cartridges of the World" The author indicates the 375 is 1/10" shorter than the 38-55 and that 375's should NEVER be fired in any rifle other than thoose specifically marked for it do to the higher pressure from the 375. If you do not have a copy of that book I can tell you the auther makes note of several rounds that are interchangable and can be fired in different chamberings however this is not one.
Buffalo Bore is out of brass for the 38-55 and is apparently waiting for Starline to come on-line with brass... no 38-55 ammunition available from them.

I have read several references that state the problems with interghanging 375 Win in 38-55 (also 41 Long Colt).

The SAAMI site has a chart of this data available on-line.

I take this data as conservative and offered with the understanding that there are many vintage pre-WWII rifles chambered in 38-55 that would not do well with high pressure.

I have spoken with a custom gun builder and have been assured that he can build a Marlin 336 chambered in either 375 Win or 38-55 Win on the same (any modern 336 Marlin) action. There is apparently no difference between the actions as he states.

I have read several post on various sites where folks mention that 375 Win can be fired from a 38-55 Marlin 336 (NEW RIFLE, not vintage) and other MODERN firearms chambered in 38-55 Win.

This is more of a curiousity with me as, as I have stated, I have reloading dies and components to make 38-55 Win ammunition to any level of pressure I desire.
Dave the book I referenced is very clear that the 375 ammo should not be fired in any weapon except thoose chambered for the round. I understand where your coming from with the antique guns and that is often the case with lever gun ammo being loaded so mild however in "Cartridges of the World" they address that issue with the 375 as well and say something to the effect that using the 375 ammo in a vintage 38-55 would almost certainly result in dissaterous consequences. Hope that helps and it probably falls under the category of you might get lucky and you might have a big problem. Not worth the risk IMO. Try ordering the BB ammo from Cabelas. They have it cataloged and most likely in stock.
This is one of the few points where I disagree with the estimable Mr Waters. I think it was pure stupidity to make a higher pressure round that's shorter than an otherwise identical low-pressure round.

It just invites an accident from some rube who believes if it chambers it must be safe. A lawsuit is inevitable.

One can buy a .375 and load it to any pressure level one desires. Dropping down in power is seldom a safety issue.

But trying to load a low-pressure round like the .38-55 with maximum charges, or -even worse- stuffing it with an entirely different cartridge just because it fits; well, that's just dumb.

Yes, I know that a recently made Marlin .38-55 is PROBABLY no different than a .375. But how can you be sure that the steel is the same, the heattreat is the same, the throat is the same, etc?

Can you fire a .375 in a .38-55? The correct answer is, yes.

I thought this would be a simple little thread. Didn’t know there would “smiley faces.”
When we began a serious comparison of the various lever action rifle cartridges of approximately the same case capacity or velocity potential - .30-30AI, .307, .375, .356 and .444 - we found the difference between the .38-55 and the .375 Winchester to be interesting and a little confusing. We knew why Winchester had to make a different cartridge – all of the older (and perhaps weaker) rifles standing in closets. Winchester knew full well the .375 cartridge was going to end up in a .38-55 rifle sooner or later. Winchester could not make the .375 cartridge longer to prevent its chambering in the .38-55 and still be able to work it through the Model 94 action. By making the cartridge case shorter and reducing the bore diameter Winchester could be reasonably certain that firing a .375 Winchester cartridge in a .38-55 rifle would not result in a “serious” high pressure situation.
We fired the .375 Winchester in the .38-55 Encore as an experiment while looking at PRE dimensions for the various cartridges. Our very limited results indicate the 200-grain .375 Winchester factory loads PRE slightly exceeded the PRE of .38-55 handloads (using new, unfired brass and .375” diameter Sierra 200 grain bullets) with maximum published loads. The .375 Winchester PRE from cases fired in the .38-55 chamber were less than those of the same cartridges fired in the Winchester Model 94 Big Bore rifle.
This was nothing more than a quick look as you well know. The Encore is throated for bullets of .3785” to .379” diameter. The .375” diameter Sierras are a pretty loose fit in the throat. I don’t know how the bullets compare to one another for bearing surface.
Current Marlin .38-55 Cowboy rifles have a bore and throat suited for .379” bullets. .375 Winchester ammunition using the .375” diameter bullets are a loose fit in the throat and the bullet will let quite a bit of gas escape past the bullet as it travels down the bore. I am not advocating using .375 Winchester ammunition in .38-55 rifles and I don’t think Ken Waters intended that either. I am just saying that through some pretty interesting forethought on the part of Winchester doing so will probably not have catastrophic consequences. Someone from Winchester probably spent quite a bit of time figuring this out in an effort to produce a powerful new cartridge that would not act as a hand grenade when it was inadvertently fired in a .38-55 rifle.
While not part of the original question, I believe shooting a .375 Winchester cartridge in a modern .38-55 Cowboy rifle is a lot safer than the practice of using .38-55 brass to handload .375 Winchester cartridges in the hope the slightly greater case capacity will give higher velocity.
Due to comments in threads I have seen on other Forums I think DaveKing has asked a reasonable question.
Dave King,
Have you corresponded with Marlin about your plan or thots?
Disclaimers and risk management aside, they may have some insights for you..jim
I graduated from Damascus H.S in the 60's..Knew alot of the Kings family...
Our farm bordered one of the family King farms..(dairy)
Who was your Dad? jim

Thanks.. This is the best "makes sense" technical discussion I have seen on this item.

jin in Oregon

My dad was...... Mr. King...... my paternal grandfather was born young Mr. Roi. (Sorry... I couldn't help it.)

I get asked about my relationship to the local King clans often in these part. Truth is I'm a transplant here, retired from the U. S. Navy and stayed for a bit. I'm originally from Eau Claire, Wisconsin but haven't lived there since 1971.

Some of the old King farms are gone, the one on Hwy 27 several miles south of Damascus is gone...being developed... about a gazillion $500,000 homes.

Doug King on Kingstead Road where King's Valley Road intersects is still around.

My children graduated from Damascus High.

Back to the 375 Win and the 38-55 Win.

I didn't call Marlin as I thought it'd be a wasted effort... Canned message, liability etc.

I'm just gonna work up a load the old fashion way and keep pushing until something indicates stop. I've read where folks are using some pretty stiff loads in the 38-55 with the Barnes .377 and 38-55 brass... loads into the 375 Win range for sure.

I'll post my results should I happen to live through the experience.
Dave, Interesting..Hope you had no problems gettin' a loan at the Bank of Damascus back when..:)
Back when Merle King owned the farm neighboring ours on rt 27..
Our farm is pretty much still there..I think the Butlers bought it after the developers who bought it back when ran into planning & zoning issues..
Been years since I was back there as all the family is gone..
Have to try and make the 40 year class reunion perhaps..but time and distance aren't favorable..
Amazingly, 85% of the class still lives withing 70 miles of where they grew up..

Concerning your project, is the initial handload effort fireing a fireforming endeavor and do you begin with reduced loads to form the cases and then work up to spped? jim
jim in Oregon

Butlers own a pile of land across the street from the old King farm. Te pond is still there as are the farm buildings and abandon house. I suspect this will be the last year though. Tregoning farmed that land for years and he just passed-on last year now Roy Stanley farms it till the houses replace everything.

Yeah, I know about folks sticking close to home. Most of everyone I went to school with still live in the same place (town/city) back in Wisconsin.

The little Cedar Grove Store is still operating as is the gas station. Clarksburg is not recognizable even from what it was two years back. All new home, thousands of them and the roads are choked with folks that have no idea of driving on narrow farm roads - - - One lane??? What's that?

Butlers spent about a half a million on a fence around the orchard to keep the deer from killing the trees. The deer are doing well with all the crops and cultivated lawns and scrubs. I spend a good bit of my time shooting crop damage deer as do a lot of other folks.

Back to the rifle.

I have loads now with Reloder 7 and the Barnes .377 255gr. The max listed for the 38-55 is 27 grains of Re-7 (advertised as 1700+-fps). I've shot a few of the 27 grain and mic'd the bases then went to 28,29 and 30 without any increase in base size. I see one fella using 32gr of Re-7 and the 255. I have no giant interest in taking things to the extreme but I'd like to get 1900 to 2000fps or so and use this rifle for deer, bear and maybe an elk. It's just a diversion for me and next year I'll have a different rifle to use and play with for a year. I'll drag the Oehler out once I'm happy with a load and get the speed, I hate to shoot over a chronograph and chase speed.

The rifle is pretty good, I made a receiver peep sight for it down in my shop and it shoots under 2" or so at 100 yards now. I don't believe I'll shoot much past 150 or 200 yards or so.
As promised (but not on the original theme).

Oehler chronograph @ ~10 feet
Marlin 336CB 24" barrel 38-55 Winchester

W-W Factory 255 grain load: (advertised as 1320fps)

6 shots: 1227fps,1344fps,1227fps,1238fps,1245fps,1265fps,1250fps,1245fps

Some case base diameters: .4166", .4165", .4166", .4150", .4163"
(2 differing lots of brass)

Reloder 7 powder
W-W Cases
Federal 210 primer
Barnes Originals 255gr .377"
Temp: 82 degrees

27 grains: 1685fps, 1740fps (listed as maximum load in the Barnes manual)
case base: .4174", .4168" (2 different brass lots)

29 grains: 1799fps, 1837fps
case base: .4176", .4174"

30 grains: 1869fps, 1842fps
case base: .4178", .4175"

31 grains: 1882fps, 1920fps There was a barely noticable stickiness in the lever extracting the 1920fps round.
case base: .4178", .4173"

Later I'll measure the cases (edited & done) but I believe I'll use about 30 grains for big animals and 27 for plinkers and deer. The factory loads are good for thin paper and small insects.
I'm suprised that the factory loads are that consistant and close to their advertised specs. How accurate was the 30 grain load?

I blasted them all into the same target at 50 yards without much regard for making a tight group... It's just a big hole so there's no pulling out the 30 grain load.

This is a "by inches" rifle and I'd suspect (later to test) it'll shoot to 2" or so at 100 yards as it did with the 27 grain load. The receiver peep hole is ~.120" and I have a larger ~.180 for dark wood hunting.
I have no experience hot rodding the .38-55 cartridge. Your loads when placed on a graph showing fps per grain of powder give the appearance you have reached a practical maximum with this powder at 30.0 grains of powder. As you shoot groups with these loads I’ll be interested in reading of the difference in accuracy between the 29.0 and the 30.0 grain load. Just to see which load your barrel likes.
If you’re Library has a copy of the 1968 Edition of the Gun Digest (22cnd Edition) look up an article by Christian Helbig: “The .444 Marlin and its Big Bore Brothers.” Helbig was quite an experimenter with the .38-55 and regularly loaded the 255 grain bullets to 1850 fps in a 20” barrel using Hercules Hi Vel No. 2.

I also look forward to seeing your case measurements. Are you measuring the case head or the pressure ring? I have found pressure ring measurements (PRE) to be useful in establishing stop points.
I'll be interested in hearing how it groups. The 38-55 Cowboy is one I find very appealing. More power than the 30-30 and just a lot more interesting IMO.
selsnslim, Stetson

Thanks for the information once again.

I haven't slugged the bore on this rifle but I suspect it's no different than the other production models and would measure in the .379 area. The Barnes Originals that I have are the .377. I believe there is a fair bit of blow-by and can reconcile the powder charges and speed relationship with this leakage in mind (my theory for what it's worth).

The BC on this bullet is advertised as .290 and with 1850fps and a 100 yard zero predicted is ~4" low at 150yds, ~8" at 175yds and ~1' at 200yds. I'll test these predictions in the field on a dry day. The rifle has receiver sights and I don't shoot from a bench so in my best (most stable form) I'll test the 30gr load for precision. If it's unacceptable or perhaps just for kicks if it is acceptable I'll try the 29gr load. This load shows ~1,950ft/lbs at the muzzle and ~1,150ft/lbs at 200 yards so I'm pleased overall (600ASL, 77degrees). I'll range from 10,000ASL and ~70degrees F. to 600ASL and 20degrees F., these difference still leave me at over 1,000ft/lbs at 200 and very little difference in drop at 200yds (~1.5" range).

I have some other powders I could use but I'm going for simplicity and if this load works I'm about done.

Here's a graphic of where I place the micrometer on the case. The spindle and anvil seem to always touch the pressure ring but just barely. I can visually identify that the they stop on the larger portion of the case witnessed by light passing between the case and the lower portion of the spindle and anvil.

I resized all the cases I fired yesterday but will once again measure some post firing and vary the location/placement of the micrometer. I'll report my findings just to follow up.

[Linked Image]

I don't have much of a firearms related periodicals library (none in fact) so I don't have access to the 22nd edition of Gun Digest at home.

I find this rifle and chambering quite interesting. I've been looking for some lighter rifles to drag along on some of my hunts and have a few others in this lever rifle category. It seems this load will be sufficient for the critters I'm after just now and it's a fun gun to shoot (once I removed the tang sight).


I found two stowaway cases while doing my pre-laundry pocket check, these are cases from factory loads. I played around with the micrometer and positioning on the case and it appears that measuring is definately position sensitive and the position is a search and find the largest area near the base but higher than one spindle width above the rim. These two cases measured (touching the rim and then slightly above the rim at largest diameter) #1) .4150 - .4156 and #2) .4158 - .4167. (I believe these may be two differing lots of ammo/brass.)

Fired some more rounds to do-over some of the measurements.

Method of measurement; Anvil touching rim: anvil above rim on ~ pressure ring



27GR RE-7, 255 Barnes .377, Fed 210

30GR RE-7, 255 Barnes .377, Fed 210

All fired case, factory and reloaded do not appear to measure consistently round, they're a bit egged and I searched for the largest measurement to report.

I shot against a target and the results do not show well for my marksmanship, perhaps it was the rotted stump I used as a rest. I fired a 5 shot group with the 27gr load and a similar group with the 30gr load. The 30gr group certaily has the better 3 of 5 shots but the 27gr group is better overall.

27gr. 2.4" with best three in 1.5"
30gr. 2.8" with best three in 0.4"

This is again with receiver sights and a brass bead front at 70 yards.

I believe I'll need to put a scope on the thing and take it to a range where there are benches to get real good results.

[quote]All fired case, factory and reloaded do not appear to measure consistently round, they're a bit egged and I searched for the largest measurement to report.

Both Winchester and Marlin lever-action rifles are reamed "eggshape" at the rear of the chamber to facilitate chambering. Every rifle from both mnufacturers that I have looked at were similar.
I too always use the largest reading. It is quick to rotate the case in one eigth turns measuring as you go to get the high reading.

If you are using the factory round bead I find these difficult to shoot well with side light. In the afternoon with soft light at your back they will show up well.
You have hunting accuracy but it will build your confidence in your rifle to shoot from the bench and "proove" the accuracy of your loads.

I assume your cases in the new unfired condition are about .4145" ?
Your measurements do not "alarm" me. I regularly see .4199" with 200 grain jacketed bullets in the .375 cases and published maximum loads. I'll post a link to a thread on the Beartooth forum from when I was comparing .38-55 brass to .375 Winchester brass with the same loads. I was reading a lot of brass substitution threads at that time and wondering what all the fuss was about. I did not experience any loose primer pockets or other visual indications of high pressure when shooting .375 Winchester load data in old R-P .38-55 cases.

About the Gun Digest, I meant to say your local Library might have it. If it does not go to the help desk and ask about an Inter-Library loan. Our Inter-Library loan system works great and has given me access to many books I could not hope to see otherwise.

I know you are setting up to be a "one load" guy but if you get the chance do not overlook Hodgdon Benchmark in the .38-55. I use it in the .375 and my father uses it with excellent results in his .38-55's.
Benchmark has one small drawback in the straight wall cases. It will sometimes leave a few very hard unburned kernals of powder in the chamber and these will put small dents in the next fired case. I have had very uniform results with Benchmark and 255 grain bullets in the .375 Winchester. When graphing loads for fps per grain of powder Benchmark seems to act a little more like an extruded powder than a ball powder in that the graph does not "break over" as you reach a maximum load level.
While I dont shoot a .38-55 it is an interesting cartridge and I'll enjoy reading about your load trials.

Edit] Dave, here is a link to a thread at Beartooh. You may want to jump to the second page about halfway down. I compared a few .38-55 cases to the .375 case. There is another longer thread on the same subject but it has escaped me for the moment.
Remeber I have no experience with hot .38-55 loads, I was just taking a look for myself at what some others were reporting at the time.

Go ahead and shoot 375 factory ammo out of your 38-55 <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" /> <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" />...cause you're just another accident waiting to happen <img src="/ubbthreads/images/graemlins/frown.gif" alt="" /> <img src="/ubbthreads/images/graemlins/frown.gif" alt="" />! And when it does you'll be one of those who'll sue Marlin... <img src="/ubbthreads/images/graemlins/mad.gif" alt="" /> <img src="/ubbthreads/images/graemlins/mad.gif" alt="" />

GET YOUR HEAD OUTTA YOUR BUTT <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> AND READ A RE-LOADING MANUAL...

luckeme –

The .30-30 has a 38,000CUP SAAMI rating, the .38-55 has a 30,000 CUP rating and the .375Win has a 52,000 CUP rating. Its pretty clear that firing .375Win ammo in a 19th century .38-55 might lead to undesirable results. In modern firearms, like Marlin, however, the situation is less clear.

It is common for manufacturers to us common components to manufacture different firearms. Do you think that Ruger uses the same receivers to build the .257 Roberts (45,000 CUP) and the .25-06 (54, 000 CUP) or do you suppose they build receivers especially for each cartridge?

Marlin’s part number for the receiver on my Marlin .375Win is the same as the part number for .30-30’s built in the same era. Furthermore, .38-55 brass drops easily into the chamber without resizing, and .38-55 brass that has been resized in my .375 dies and loaded chambers and fires fine. The difference is the .375 uses a .375 bore and the .38-55 typically uses a .379 bore. I suspect .375 ammo fired in a modern Marlin would pose no safety issue but accuracy would probably be unacceptable.


I just now measured some unfired W-W factory ammo cases.

Measured touching the rim.

(from a mixed lot - bag full of rounds)

From a new Winchester box.

I'll read that thread at Beartooth later today.


Thanks or the reply. Your post is pretty much in line with that I'm thinking in regard to the 375 Win and 38-55 Win in the new Marlins.
Some more information about the 38-55.

(I'd say this thread has been officially hijacked and is no longer about 375 Win in a 38-55 Marlin.)

Mentioned previously is the bore diameter on the 38-55s and also blow-by using smaller projectiles.

I have recovered a bullet, a Barnes Original .377" 255gr 38-55 bullet for examination. Under a loupe I can see that there is no indication that the bullet had made contact with the bottom of the groove. The engraving from the lands is minimal and there appears to be a small amount of scuffing before the bullet settled onto a land. The trailing (?) edge of the land striation mark has some curled up and displaced jacket material.

All-in-all I believe the bullet worked well and I have achieved sufficient speed with the bullet from this rifle. Based on the bullet examination and bore diameter listing I do feel there is some level of blow-by and therefore some loss of efficiency.

I have been searching for a bullet in the .378 or .379 range that is a standard copper jacketed hunting bullet but as yet have had no luck. I may try some of the hard alloy cast gas check bullets and begin anew with the load workup although that is not what I'd prefer.

Impact velocity for this bullet at 140 yards was about 1550fps and 1350ft/lbs energy, retained weight is 224.2gr (~88%).

[Linked Image]

If you are going to try lead bullets I would suggest you first make an impact casting of your chamber throat. Fill a case with lead and then push a lead plug down the bore onto the lead filled case. Using a piece of drill rod that fits as close as reasonably possible upset the lead plug. When you withdraw the case you will have to push out the lead plug (into the chamber). This will give you a good idea of the throat length and diameter.
If you fill the throat gas will not escape past the bullet as it enters the bore.
A cerrosafe casting will also provide the same measurements

I suggest that you use a little softer alloy rather than a “hard cast” bullet. The vast majority of the bullets I cast and shoot are less than 20 bhn. I prefer bullets with a hardness of between 12 and 14 bhn for hunting critters of deer size and smaller.

You may want to check with Marshal Stanton at Beartooth bullets. Marshal offers bullets heat-treated to 22 bhn or on special order he will furnish bullets at 18 bhn. I believe if you try both bullets you will find it easier to develop accurate hunting loads with the softer bullets. If you fill the throat you will not have problems with leading.
Marshall can provide special sizing diameters and he is familiar with the Marlin rifles chambered for the .38-55 cartridge.
You will not find a better cast bullet than Veral Smith’s LBT style bullets but if you prefer to cast your own and want to get started for the least money you will do well to start with the Lee 255 grain bevel base bullet mold. The mold is low cost and the bullet seems to shoot very well in both my .375 Winchester and my Fathers .38-55 Encore. We shoot them as cast with tumble lube and hand lubed using Javalina 50/50 Alox.
You will have no trouble shooting cast bullets at full power in the .38-55.
04 July 2006 Update

I put a 4X scope on the rifle to test the loads at the range.

I cleared a lot of brass of bullets and powder, factory Winchester and Factory UltraMax Pb stuff, to get the brass for reloading the Barnes. Most of the factory groups were unremarkable but decent. Mostly I just plunk rounds into the berm to empty the brass but I did fire several strings onto paper with the factory rounds.

The Winchester factory went to ~1.494" for a six shot group I shot on paper.
The UltraMax lead rounds on paper went into ~1.93".

I only had 5 of the 30 grains of RE7 loads and didn't want to shoot up all my ammo so 3 shots and they went into ~.449.

[Linked Image]

I fired the 32grs and 33grs of RE7 loads I had left from a few days back, again recapturing brass.

32gr RE7
Touching the rim: on pressure ring
0.4188" : 0.4188"
0.4186" : 0.4187"

33gr RE7
Touching the rim: on pressure ring
0.4191" : 0.4191"
0.4184" : 0.4184

(I have mixed lots of brass and I suspect the two dissimilar readings on the 33gr loads may be due to this Lot issue.)

I had a macro picture taken of the .377" 255Gr Barnes Original bullet I recovered. The posted picture is a small version and the link will lead to a full size image (~1meg). I believe I'm seeing some scuffing at the leade until the rifling lands get a good hold and also I see no indication of any contact with the grooves... You all can judge for yourself and let me know if I'm all wet.

377" Barnes Original post firing in a Marlin 336CB 38-55 24" barrel, 30grains of RE7 chronograph ~ 1850 fps muzzle.

[Linked Image]

Hi-Res .377" Barnes Original post firing in a Marlin 336CB 38-55
An interesting picture. Is the base of the bullet cupped? I am thinking not as the .377" diameter in the .378" barrel allows enough gas to slip by the bullet to prevent this.

With the .377" diameter bullet I would consider the 33.0 grain load maximum. If you switch to a jacketed bullet of larger diameter I would lower the powder charge.
When working with the .30-30AI we went to .422" on many ocassions with no indications of trouble - but - This was clearly a greater pressure indication than we felt comfortable with for hunting loads at all temperatures. There is no point in looking for a problem with your hunting loads just for a few fps increase.

Looking at my load notes for cast bulets I found some stuff on a John Taffin article on the Marlin .38-55 Cowboy rifle from the Feb. 2000 issue of Guns magazine. John used a load of 30.0 grains of Reloder 7 behind the 250 grain RCBS gas check bullet and got 1758 fps from the 24" barrel of his Marlin Cowboy rifle. He sized his bullets to .379". John tried bullets of .377 and .379" and said he could not see a difference in accuracy - I assume he was using only the factory sights.
While it has been awhile since I have been there, I believe John Taffin has a web page linked with Sixgunner.com and many of his articles are posted there.
My notes indicate John called Marlin and Marlin says their .38-55 rifles have a groove diameter of .378".

The base of the bullet is not cupped.

I believe I'll stay with the 30gr load as it's fine for precision in my mind and I have no plans to shoot this rifle much past 150 yards for deer at present.

I'm still considering getting a larger diameter bullet but mostly just for educational purposes. There seems to be a place or two that have .378 bullets and there's always the Hawk soft copper jacket model to try. I would of course and as you state lower my powder charge (essentially start over and beginning load values) when switching bullets.

Here's a link I found to an article by John Taffin... Thanks


That looks like the article I saw in Guns.

1850 fps for a 255 grain bullet is a pretty good load.

While you are gathering data look for a book by Freeman "How To Hunt Deer." Freeman used the .38-55 in Maine. He had one arm as I recal.

I don't read much nowadays (hardcopy books) but if I have a chance I'll hunt it up but I can tell you right from the git-go that I'm not about to lop off an arm to continue using the 38-55! <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />

1850fps is adequate and reasonable, I'm pretty happy with the performance and again its a play thing that I'll use for a few deer, bear and maybe an elk.

I'm very pleased with the results of the 30gr load and I feel pretty confident that the little rifle will perform consistently. This has been a pretty good learning experience for me as I have little experience with lever guns and old chamberings.

Thanks for taking the time to help me along and for the very informative links and such, its made this part of this adventure faster, easier and more informative. I'd imagine there's a lot more to learn but this particular part is setting well right now and I'll rest here for a little bit before I venture onto the next level. I have a few hunts coming up soon and I also need to ready other gear, archery elk and mule deer if I'm lucky.

You may or may not have run across these threads in your looking around. At least two of them fit in with you brass question






Thanks for the additional information, it was very informative.

I just recently added to my levergun collection and now I have a Winchester Big Bore in 375, a 94AE in 356 and a pair of older Marlins (circa 1950) in 35 Rem (336A 24" barrel) and 30-30 (336 R.C.). I guess I'll be slugging bores in these too.
I prefer the .307 to all of the modern "Big Bore" lever actions but I have been shooting the .356 for quite awhile and like the cartridge very much. I prefer the .307 and .356 to the .375 Win but I have no complaints with the .375.

For your .356 the 200 grain RCBS bullet will prove very useful. I have never heard of a Winchester M-94BB that would not shoot the RCBS bullet well.

There are lots of old threads on the .307, .356 and .444 on the Beartooth forum that will provide plenty of insite into bullet and powder selection. Every one has a different favorite combination!

Check out this link to a thread on leverguns. I am sending it as there are links to five interesting .35 Remington threads on the Marlin Owners Board. This is a continuation of a series of threads that started on the old Marlin Talk board. These deal with the loading of the Modern or +P .35 Remington for modern rifles. Makes for an interesting discussion.

Just a bit more info to round this out.

I made a cast of the chamber on this 38-55

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The bore measures .3806 at the chamber near as I can tell.

There's no (minimal) leade/throat as I can see either.
"the 375 is 1/10" shorter than the 38-55"

The .44 Special is 1/10" shorter than the .44 Magnum.

The .38 Special is 1/10" shorter than the .357 Magnum.

Once fired cases, would be longer than new brass.


It would appear from your pix that you chamber is normal for the 38-55. There is little or no leade in these rifles so the OAL must be controlled. Any over lenght loads will not chamber. I have several rifles in both calibers and all are critical on loaded length.

Is it safe to shoot 375 Win. in a 38-55? Yes it is! But it will not be accurate so why do it? Doing so will offer no advantage or benefits.

The .375 was a stretch for the 336 action in the first place, as it operates considerably above the 336s safety threshold of 40,000 psi.
375 brass is heavier constructed than 38-55 in order to stand up to the extra pressure, an the .375 uses that size projectile, while the 38-55 uses between a .377 an .379.
Couple thousands of an inch might not sound like much, but thats all it takes to scatter bullets instead of droppin em in.
.38-55s have dimensions all over, some guns run as much as .380, others considerably tighter, brass also has been shortened recently. Marlin claimed their 38-55 to be right in the .379 range, but I know of at least one gun where the chamber was too small fer anything more than .377. Options here-chamber ream, or shoot jacketed.
Anywho, the reason folks tell all of you not to shoot .375s has to do with a few things-fist of all, the cartridge is shorter, an will not fill the chamber, if you follow up shootin with a standard oal number you could wind up imbedding the chamber, an at the very least creating a hassel of cleaning, at the most causing damage to yer gun.
Secondly, yer .375 is gonna be accuracy challenged at best, an at worst shootin that undersize of a bullet could wind up damaging both grooves an lands-at the very least, youll have a bunch of blowby, which greatly increases yer chances of extra work removin all that fouling.
Third is that the .375 pressures are rated well over the threshold for the standard Marlin action, an this means you could run into head space issues real quick.
Sure, the ol .375/336s look identical, but will anyone swear that the newer cb recieved the same heat treating? I sure won't.
Last, if you need yer 38-55 to have greater velocity, then go to a slightly lighter bullet-its no sweat to shoot 220s or even 200s an get to or even better a little the 2,000 fps range.
If you really have a hankerin for the .375, I know there are still a few floatin around, save yer coin, get one of em, an keep that cb in shape.
Good luck n good shootin

MAK's post is a little overstated but correct in substance.

Where did you find that arbitrary "safety threshold" of 40,000 psi? That is rubbish and you know it.

The .375 was a stretch for the 336 action in the first place, as it operates considerably above the 336s safety threshold of 40,000 psi.

375 brass is heavier constructed than 38-55 in order to stand up to the extra pressure...

Third is that the .375 pressures are rated well over the threshold for the standard Marlin action, an this means you could run into head space issues real quick.

Sure, the ol .375/336s look identical, but will anyone swear that the newer cb recieved the same heat treating?...

Mak -

Marllin seems quite happy putting a 44,000 CUP (.444 Marlin) or 43,500 PSI (450 Marlin) pressure limit on the 336 actions, so 40,000 PSI is a little low.

Whether .375 brass has thicker walls is a matter of debate. I have WW brass in both and will check for myself one of these days, but others claim they ahve found no difference.

Firing a .375 Win cartridge with a .375" bullet is going to reduce pressures considerably when bore is .377" or larger. How much I will leave to others to test.

The receiver part numbers for my Marlin 375 and Marlin 336's of the same era are identical. What does that say about heat treatment? Also identical.
OK-40,000 psi range.
Guess I just consider a few thou over or under still around 40,000. Besides, cartridge components will have pressure variations, just the nature of the beast, an with a 40,000 psi limit you'll never break yer gun.
Point is, the Marlin 336 in standard form has an acceptable pressure limit of around 40,000 psi, or about the same as the Winchester 94.
Yep, the 375 will have a bunch of lower pressure in the 38-55, cuz so much of the gas is whooshing on by-by the way that horrible sound will be your barrel sayin bye bye. I suppose I'll reiterate that the .375 is not interchangeable with the 38-55.
I tell ya, I'd sure as heck hate to get a hold of a used gun from you folks, probably work as a chile stirrer an not much more.
I dunno what ever happened to common sense in this counrty, but it sure gives one pause...
If pressure is an issue, you reduce your charge or you change your component/powder choice-you don go to a cartridge your gun is not chambered for.
I would not go by a cusrory review of part numbers to make my conclusion about pressure. Marlin, remember has never chambered another 50,000 psi cartridge in their 336-coincidence? Maybe, but I guess I like my guns an finger to be intact-I know, thats patently ridiculous, but there it is.
So, the advice from me, Mr. slow an low, is to review yer field performance before you fill yr head with all kinds of numbers, you'll find, if yer honest, that at levergun ranges, with good bullets, that those low velocity numbers work right fine-your ears'll agree an so will yer shoulder.
So, if you need more fire, refrain from usin the 375 in the 38-55. Go get you a real 375, or go custom an have one made from a BB action. Then, you can brethe all that fire till your shoulder is as numb as a politicians sense of honesty.
Mak -

I’m not recommending shooting a .375 in a .38-55, just pointing out that the pressure would be lower than in a properly sized .375 barrel. In fact I DON’T recommend it. If I was going to hot-rod a .38-55 I’d use .38-55 brass and properly sized, gas-checked bullets. Not recommending that, either, but I do recommend a .375 Win.

I like my guns intact, too. BTW, Marlin DID chamber another 52,000 CUP round in the 336 frame – it was called the .356 Winchester. I have not heard of any .356’s or .375’s blowing up with factory ammo or even handloads for that matter.

A cursory review of part numbers? You go to order a blued receiver for a Marlin .375 Win or a 336 made in the same time frame and there is only one part number to order. If you can find a different part number please let me know.

By the way, the .356 Winchester may have had the same receiver part number as well – I think so but can’t recall, looked it up once but since I don’t have one the answer didn’t stick in my memory.
All the .356, and .375 receivers are the same as every other .336 receiver. Marlin did try using a different barrel thread design to strengthen the action for the .307, but abandoned it.

That is until now. They use the modified barrel thread design on the new .308 marlin express receivers.

Yep, the 336 was also chambered in the late, great .356 WCF.
If I recall correct, the .375 predated the .356/.307, an like W. says, the 307 was announced an never built.
In any case, the 356 was indeed a high pressure number.
My point about heat treating is that certain parts may have had a lil extra dose, or may not, I've asked this question of others more in the know than me.
Marlin in those days apparantly did not do a ruger, they did a kimber-their parts were chosen for their gun, an rode along together till done-thus part no.s alone won tell the whole story.
Maybe you know more n me, an maybe you can put it to rest?
Anywho, were lucky that there still are .375s/.356s out there-they really are great cartridges.

Marlin in those days apparantly did not do a ruger, they did a kimber-their parts were chosen for their gun, an rode along together till done-thus part no.s alone won tell the whole story.
Maybe you know more n me, an maybe you can put it to rest?
Anywho, were lucky that there still are .375s/.356s out there-they really are great cartridges.

The other parts would not go along for the ride during heat treatment, and that’s where the difference in strength would come from. Here are a few part numbers from Marlin schematics:

407690 = Receiver, Marlin and Glenfield 336C (.30-30)
407690 = Receiver, Marlin and Glenfield 336ER (.356 Win)
407690 = Receiver, Marlin and Glenfield 375 (.375 Win)

That’s Marlin’s part numbers and the Marlin drawings they were taken from. The actual description is the same in every case, including for the Model 375:

“Receiver, .30-30, .35, .44, .307 & .356 Cal. (FFL Req'd)*”

Note that the .307 is listed, even though Marlin never shipped any.

I agree those who have .356’s and .375’s are lucky.
Please take this as intended. I do not wish to raise hackles or throw insults.

Among the cartridges that will “shoot” in a .38-55 rifle are the .38-55 (duh!), the .22 Savage Hi-Power, the .25-35, the 7-30 Waters, the .30-30, the .32 Win Special, and the .375 Win. Add to that list a host of non-factory rounds like the .30 Herrett, .357 Herrett, 7mm IHMSA, .25 Bullberry, .35-30, .30-30AI and several more.

But “shoot” should mean more to us than the ability to chamber and go “bang” - or perhaps “pop” or even “fizz.”

If Marlin had intended their rifles to shoot both the .38-55 and the .375 Win, they would be roll-stamped as such. They are NOT. A person can argue all day long about part numbers, barrel alloys, heat treatment and pressure levels, but those arguments prove absolutely nothing except the possession of a creative mentality or perhaps wishful thinking.

Doing so is poor judgment, period. It serves no useful purpose. If you want a .375 rifle, by all means buy one. The .38-55 is perfectly useful and usable as is – and that's how it should be used: AS IS.
This little exercise has been a bit of an adventure for me, and once again by simply stepping around the stones and ruts in the road I have ventured forth and learned a good deal of useful information. I would like to thanks those with a likewise adventurous spirit for the assistance they provided and to the others I hope the dust of our passing by wasn't too uncomfortable.

If Marlin had intended their rifles to shoot both the .38-55 and the .375 Win, they would be roll-stamped as such. They are NOT. A person can argue all day long about part numbers, barrel alloys, heat treatment and pressure levels, but those arguments prove absolutely nothing except the possession of a creative mentality or perhaps wishful thinking.

Doing so is poor judgment, period. It serves no useful purpose. If you want a .375 rifle, by all means buy one. The .38-55 is perfectly useful and usable as is – and that's how it should be used: AS IS.

If you go back and reread my posts you will see where I stated:

"I’m not recommending shooting a .375 in a .38-55, just pointing out that the pressure would be lower than in a properly sized .375 barrel. In fact I DON’T recommend it. "

That said, the receiver part numbers are indeed identical.

FWIW, my .375 chamber is overly long and I have used .38-55 brass to build longer .375 Win loads. Shooting .375 brass in the chamber is somewhat like shooting .38 Specials in a .357 Mag chamber. After some experimentation, however, I gave it up as I only had 50 .35-55 cases and 500 .375 cases and didn't feel the effort to keep them separate was worth any potential gains I might get from the .38-55 brass.
Guess what I got back in the mail today! My marlin 30TK rebored from 30-30 to .375 winchester. Took 12 days including ship time and cost $170 including shipping and insurance both ways. I hope it shoots as good as it feeds.


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Great news, Weagle. Anxious to see how it performs.
Weagle,who done the work ?

I've used 38-55 brass in my 94 BB 375 Win. for several years,since the brass is thinner you can get more powder in it.I also make brass for my 375 Winny useing 30-30 brass...
no problems..ask PACO over at Leverguns.com forum..He will tell you the same...
Jesse Ocumpaugh out in Oregon did the conversion. He advertises on Gunsamerica.


He doesn't list the .375 conversion on his flyer, but I talked to him and he said he could do the .375.

I ran a couple of boxes of factory ammo through it yesterday and it was very accurate. Most of the 3 shot groups were right at an inch and I think it would do a litlle better once I clean the trigger up (possibly the worst marlin trigger I've ever tried)

Buckeye, it is my considered opinion that much of what Paco Kelly says is downright dangerous. Many if not most of his top-end loads raise the hackles on my neck in trepidation.

Using reformed .30-30 brass for full power .375 loads (or above with even MORE powder!) is simply foolhardy. Again, my opinion only. It's your face snuggled up next to that receiver, not mine. I sincerely wish you well.
While I find it potentially interestin to imagine any 336 capable of digesting BB pressures, I also find it interestin that when Marlin creates their own cartridges, they stay well below Win BB pressure limits.
The exception to this rule seems to be their new 30 cal, yet Marlin admits to several upgrades to handle this lil number.
I've been called old, slow n low, an in fact even worse, but my personal point of view goes back to 40,000 or so. Maybe I'm just a stick in the mud, but I think theres a reason Marlin stays around 40 thou with darn near ever cartridge.
Goin back, the .375 was a bold move by Win an Marlin. It was an attempt to update the ol Ballard number with modern components. They changed it around in order for the two rounds to be obviously different, thus most folks would be savvy enuf to not load one round in the other type of gun.
Paco has been all over the internet with his views on hotrodding anything that fires a cartridge, an hes been vocal on usin 38-55 brass in the 375 for more powder capacity. He seems to think that even the .375 should go faster. Well, considerin how many guns hes blown up, other folks should be lookin at his stuff a lil sideways.
1ST-the 38-55 brass wont hold up to BB + Paco levels of pressure past a couple of loadings. Bein straight walls, they won't warn ya before they let go. Paco should know this, but I guess hes a great internet hero, an above all this mundane stuff.
Just like with the .35 Rem., the 38-55 is limited to its pressure levels. Thats why we have the .358 Win and the .375 Win.
Any who, any 336 may be able to handle BB pressure levels, but I personally am more comfortable in the 40 thou range.
You are a wise soul, Mak.

In the flying community, we have an axiom:

There are old pilots and there are bold pilots.
But there are no old AND bold pilots.

That holds true for reloaders as well. At least for reloaders with all their original body parts still intact and attached.
What about Chuck Yeager, Neil Armstrong, etc?
or Pugs (heck, even ME!)

No, there's a difference between aggressive but competent bold and "Hold my beer and watch this" bold.

I have met Yeager, Deke Slayton, "Hoot" Gibson, John Young, Bob Crippen, Joe Engle, Mike Smith and several other famous pilots and astronauts. I have flown and worked with a host of combat pilots. All of them were bold in the sense of being willing to push the corners of the envelope to achieve an immediate and pressing result. None of them were in any way "bold" in the sense of wildness or insanity.

But that's far from the point of this thread. The point being: Load safe and you'll shoot often. Load crazy and you may shoot only once.
Best to let it go Dave. The intent of your original post is irrelevant; the thread no longer follows your question. It is unlikely current posters understand the intent of your original question.
The bending of your thread would have taken place without regard to the cartridge or action type under discussion. This is not a fault peculiar to this or any other Forum nor is it my intent to disparage the comments of those who have very real safety concerns over the advisability of loading cartridges to higher than SAAMI specifications.
Due to discussions on internet forums and writing in the mainstream press – as exemplified by Christian Helbig and his Gun Digest article – yours was a legitimate question with regard to bullet fit and high-performance loading data. The cartridge in question has been loaded to higher velocity levels for quite some time as is evidenced by examining data referenced by Phil Sharp in his book: Complete Guide To Handloading and by reading magazine columns such as the American Rifleman’s Dope Bag, as “orchestrated” by Al Barr.
All open forum discussions of high-pressure loading data for wildcat cartridges intended for use in lever-action rifles will take this turn sooner or later. And this is with posters on both sides of the issue having the best of intentions. I am not aware of an open forum where the discussion of reloading for wildcat or special use cartridges will not eventually become a heated discussion with the original intent lost in the swirl of dust from post and counter post. If there is a forum on the internet where a handloader is able to discuss reloading for cartridges such as the .25-35AI, .30-30AI, .30-.348AI or other high-performance wildcat lever-action cartridges, I am not aware of it.

William Iorg
Things have changed quite a bit since the time of phil sharpe.
In his day, 38-55s were loaded with special high velocity powders by the factory, for specific actions. There was lil thought or consideration for longevity of the firearm, an it was assumed that the user would be smart enuff to just use em in the offically sanctioned guns.
The 375 is not directly interchangable w/38-55. This should be obvious. There is nothin wildcat about the 375 nor 38-55, an those who load to +P+ levels are not makin a wildcat.
Even heavy loaded 38-55s were low pressure numbers compared to the 375. If I recall correct, the Western HV loads clocked at around 1750 fps with a 250 gr bullet. Using this as a baseline, even todays so called modest loads of 1850 seem a lil steep.
If you or anyone else has a burnin need to load a cartridge to the point of a grenade, an publicise it, then expect somebody to wave a red flag.
What is really irrelevant is tryin to turn every levergun cartridge into a competitor with todays short magnums for borin bolt guns.
It can be argued indefinitely about loadin levels, component choices, an action strengths, but the real value of leverguns an traditional cartridges today is their low muzzle blast, handy dimensions, fast aquisition, an effective-yep effective cartridges at what seems like crawling speeds in todays world.
Its the nature of man to always work to improve, but its also the nature of man to recall whats valuable, what works, an stick to it.
Nicely done, Mak. Bravo.
I went back and re-read the entire thread. I don’t believe Dave King or I ever advocated the .375 Winchester and .38-55 are or should be considered, interchangeable. Dave King was pretty clear in his initial postings the question was out of “curiosity.”
I believe my comment about the high-pressure .38-55 being treated as a wildcat or special use cartridge is reasonable – loaded to higher pressure it is not the same cartridge. I express this thought as I think of writing in the main-stream press and in books of higher-pressure loading data for the .38-55, .250 Savage and .257 Roberts as examples. Special use cartridges such as Ron Carmichaels .356 Rimless are perhaps best described as a semi-wildcat as it utilizes a standard cartridge case (.358 Winchester) loaded to a shorter overall length with different types of bullets (flat nose Vs spitzer).
I don’t believe either of us suggested loading data that would produce a “grenade” when used in a rifle of recent manufacture.
I prefer somewhat heavy for the caliber bullets in my lever-action rifles and have experience with the remarkable killing properties of the heavy bullet driven at modest velocities. I do not agree that all lever-action rifles must be short in order to be handy.
Personal experience with two 26-inch barrel .30-30’s has proven to me these are powerful and quite handy rifles. I primarily hunt West Texas whitetail deer and pigs with my lever-action rifles. I use most of the modern lever-action cartridges. I have experienced more “one-shot-dropped-in-its-tracks-kills” with the .307 Winchester and the 170-grain bullet driven at 2,350 fps than with any other modern lever-action rifle. This is not a maximum load for the .307 cartridge. The words of Townsend Whelen and T. R. Truesdell – no one hunter can gain enough experience to make definitive statements on killing power are applicable here.
As a teenager I read articles by Ken Waters (1958 Gun Digest comes to mind), Dean Grennell, P. O. Ackley, Homer Powley, Frank Hemphill, H. V. Stent, Henry Stebbins and others comments on the killing power and handiness of lever-action rifles. The effectiveness of cartridges such as the .348 Winchester and its Model 71 rifle and carbine were discussed. There were a number of discussions of wildcat cartridges such as the .30-.348 and the improved version. The .25-35AI, ,30-30AI. .308/.444 and several other wildcat cartridges were discussed and I have played with several of them – recently. I see little difference in a discussion of one of these wildcat cartridges and the high-pressure loading of the .38-55, as long as the approach is tempered with caution and a definite goal is established prior to stepping outside the lines.
In discussions of this type my skill at communicating my thoughts often comes up a bit short. Shooting and reloading is simply hobby for most of us. It should be fun and interesting. If we cannot have a reasonable discussion of these questions on a well moderated shooting forum such as the Campfire, where can we?

William Iorg
Originally Posted by Mak
...If you or anyone else has a burnin need to load a cartridge to the point of a grenade, an publicise it, then expect somebody to wave a red flag.

...the real value of leverguns an traditional cartridges today is their low muzzle blast, handy dimensions, fast aquisition, an effective-yep effective cartridges at what seems like crawling speeds in todays world.
Its the nature of man to always work to improve, but its also the nature of man to recall whats valuable, what works, an stick to it.

I would have to reread the thread, but I don't think anyone was recommending loading a cartridge to the point of a grenade.

Is it reasonable to shoot a .375 Marlin or a Marlin in .356 Win, both of which have the exact same receiver as a .30-30 made in the same era - per Marlin's own parts lists for the respective models? Yes.

Would Marlin would have released rifles for the 52,000 CUP .375 or .356 cartridges if they were grenades waiting to explode? Not at all likely.

Did Marlin do enough research to know if these loads would be safe or not? Almost certainly.

Is the margin of safety less than for a 38,000 CUP .30-30 built on the same receiver? Of course. But that does not mean they are unsafe.

Is a person a lunatic if they take a modern Marlin in .38-55 and load it beyond the 30,000 CUP SAAMI spec? I guess that depends on how high they take the pressures.

30,000 CUP .38-55
38,000 CUP .30-30
43,500 PSI .450 Marlin
44,000 CUP .444 Marlin
52,000 CUP .356 Win
52,000 CUP .375 Win

Then there are the 40,000 CUP .45-70 loads offered by various powder manufacturers that are specifically for Marlins, with Marlin's tacit approval. And the new .308 Marlin is expected to be in the mid-40's KPSI.

Seeems to me the modern Marlins can handle well above 30,000 CUP.

Does it make sense to shoot .375's in a .38-55? Not to me, for several reasons. Is it dangerous? Given the .375 bullet in an oversize .377-.378 bore, I'd say probably not.

The real value of leverguns varies depending on who is doing the valuing. I enjoy my .375 and .45-70 a lot, in spite of the additional blast and recoil compared to a .30-30 or .38-55, and I load 130's to 2500fps in the .30-30 for plinking clay pigeons at 200 yards and beyond - hardly a "crawling speed". They all have scopes, which is heresy to some folks. Not that I give a rip what others think about my levers or how they should look or what loads should be used in them. So far they have been 100% effective on game, from antelope to elk, with loads and acoutrements of my choosing.

Remember how many rifles turned to shrapnel that were chambered for the .30 Newton?
Remember how howlin mad folks got when Rem released the .35 Whelen? Seems folks were overloadin that number. Read any of the threads here about folks shootin, an some of the velocities claimed? Seems I recall a recent thread where the poster was talkin 2500 fps out of a 45-70.
Folks, you have to be aware that reloading is a safe an rewarding discipline only when it is that-a discipline. I have personly known several folks whose only qualification for reloading was that they had the daneiro to buy all those nice shiny tools.
You can't talk about 375 velocities in the 38-55, for instance, without taking those steps into this zone.
Sorry, guys, but this to me is a hairs breadth away from the proverbial grenade.
One of the reasons we still admire Phil Sharpe is that he brought some science to the alchemy. Unfortunately, we still have to contend with folks who think the bigger the case, the more powder they should pour in.
These days, there are so many good cartridges, the slots where wildcats can fill is pretty small, but if thats where your at, thats fine. I've heard that Texas has a few really good ballisticians, and they have the advanced equipment to study things like pressure an which powders work best. Why not look em up, you might be on to the next fun thing-your wilcat.
Well, it happened again, just heard about another gun blow up and yep-it blew up with reloads. The first five or six went just fine, but somwhere in the next series of shootin, kaboom. Yep, there was injury.
I've got to say, that the pecieved strength of the reciever is but one part of the equation.
I've got say, that nothin here is indended as a personal attack, it is intended as a call to responsibility, to discretion and to sound practice. Accidents can happen to anyone, but when we follow safe procedures, we minimize that chance.
Weve already covered the pressure issues, weve already covered the 375/38-55 and right now, I have little to add about it.
Its not about scopes, guys, its not about huntin, an its not about about bein onery. Its about SAFE SOUND PRACTICE.
Good luck n good shootin
Mak -

I don't know anything about the rifles that were chambered for the Newton, nor are they relevant, except its a reminder as to why I don't shoot antiques. The question at hand regards Marlins of modern manufacture.

By the way, 2500fps out of a .45-70 is perfectly reasonable - depending on the rifle used. In a Ruger #1 a 300g can easily be pushed that fast. Under 50,000 CUP according to Hodgdon. Definitely not something I would try in my Marlin.

On another forum I was blasted by the owner for suggesting that someone might find that .38-55 brass , resized in a .375 die, fit their Marlin .375 Win better than .375 brass, as it does mine and several other Marln 375's of which I am aware. He also blasted me for suggesting velocities that might be obtained by doing so, even though the velocities and pressures I was discussing were well below maximum for the .375 Win. The owner later admitted he had no idea what pressures or velocities were or what the situation was with Marlin 375 rifle chambers as he had no experience with the caliber. He was just blindly working off the idea that you don't fire a rifle using brass with a different headstamp than what is on the barrel. (Guess all the guys reforming brass into a different cartridge are doing something dangerous, regardless of the situation.) The owner looked like a fool and later deleted the entire thread.

The Marlin 1985 is chambered for the 28,000 CUP .45-70 cartridge, yet 40,000 CUP data abounds and Marlin doesn't complain. If the 40,000 CUP data was dangerous you can bet that Marlin would insist that the data providers not list the data as being safe in Marlin rifles.

It might be that Marlin, when Marlina was making 38-55 Cowboy rifles a few years back, went to the expense and effort of designing completely new receivers and made them substantially weaker than the receivers used in other 336's, when the raw recievers Marlin was already using would have worked just as well with no or only minor modifications to the final dimensions (like perhaps a slightly longer ejection port). The economics of modern manufacturing dictate reusing the same basic receiver, just as they have done before.

The situation is very much like that with my .257 Roberts, a Ruger M77. The .257 Roberts has a SAAMI limit of 45,000 CUP yet Ruger chambers the same receiver for cartridges that go as high as 54,000 CUP or 65,000 PSI. It is little wonder that I feel perfectly safe using +P data provided by powder manufacturers when loading for the Roberts.

There are a couple points here. The first is that the modern Marlin .38-55's are not necessarliy a grenade waiting to go off if the 30,000 CUP .38-55 SAAMI pressures are exceeded - it depends on the pressure being reached. Do I recommend doing so? No. The second is that each reloading situation needs to be evaluated on its own merits. Using +P data or loads is not necessarily unsafe simply because it is +P.

Is it possible to safely obtain .375 Win velocities in a Marln .38-55? I wouldn't try it for a number of reasons. Do I think firing a .375 Win in a .38-55 marlin is going to cause it to explode? Not likely, for a number of reasons, including the .378" bore diameter Marlin used in the .38-55s and resultant lower pressures. Could it? Its possible - stainless Sako rifles were blowing up with factory loads, too. Are the results likely to be satisfactory. Probably not.

I brought up the Newton an the Whelen to point out that wilcats often enuf operate at wilcat pressures, an that as I said before, this can lead to fireworks of the wrong kind.
I dunno about this other forum, an if you are drawin a parallel, be corrected that I'm not personally attackin anybody, an if the other parrallel is that I'm an idiot like this other guy-well, you are welcome to your point of view.
I'm gettin to the point of repeatin myself again and again here, but I do it, cuz folks on this electronic gizmo seem to think that like the guy with the 45-70 Marlin, that anything goes.
I'm gettin to think that we have a large number of suisidal reloaders in this country.
Headstamps can be a convenient method for organizing cartridges according to pressure, it all depends on your system.
Pressure for any hobby reloader are at best an indirect estimate, I wont go into all the variables, I'm gettin too tired to delve back into it all.
Pressure variations are common even with factory loads, we need to expect it, thus we need to cut the potential for accident down-for high pressure loads, my opinion is to use suitable heavy duty brass.
I've worked with a friend who I consider to be one of the best hobby reloaders I've ever known, and the thing about this hobby to remember is that everything effects everthing else-get it right an you'll take home the lever action silhouette trophy, do it wrong, an well...
So, if you want get your 2500 fps. I could say go get you a 458 Win mag., leave the 45-70 alone. I could say the 38-55 will do anything its supposed to do at 1500-1700fps, but it won't matter, there'll still be some suicide jockey whos smarter n me, who will justify the desire for extra speed, an who will argue about it till the cows come home.
I'm tired of this thread, but I still need to reiterate to any who are reading this that reloading is potentially dangerous, potentially deadly, an if you follow the rules, you'll stay safe, and that if you really think your smart enuff to break the rules, well, youre probably not.
Said my piece.
Mak -

It was absolutely NOT my intent to suggest you were a fool. In fact I think we agree on much more than it might look like to some reading our posts.

Pushing a 300g bullet to 2500fps in a Marlin is suicidal IMHO - a point I was not clear on in my previous post.

Here is a link to a very interesting thread on the Lever-guns board.

The new unprimed .375 Winchester cases run 2.010” as I measure them but some list them at 2.020”.
The current production Winchester .38-55 cases measure 2.080”.
The few original .38-55 cases I have measure 2.129”.

I wish this poster would have measured the center case in the picture and given us its length.
This will certainly warrant some caution on the part of those who have anxiously awaiting the original length Starline .38-55 brass. A chamber cast is a necessity prior to proceeding with over length cartridge cases.

This particular example validates the view taken by Rocky with regard to shooting .38-55 ammunition in the .375 Winchester. I still believe that your well thought out approach to this question is valid but the picture is a good example of the result of shooting the original length .38-55 cases in the shorter .375 Winchester chamber.
I still believe Winchesters conservative approach with regard to bullet diameter and case length was well thought out and will prevent accidents if a .375 Winchester cartridge is inadvertently fired in a .38-55 rifle of modern construction.

Here is a link to the thread and very interesting – if limited - comments.

Interesting thread, glad I found it.

Dave, I haven't tried 375 ammo in the 38-55 CB since I hardly ever use factory stuff. But I can offer the following data fired in a CB with .3809" grooves.

All loads use Benchmark:
Horn 220FP 375"/37 gr =2001 f/s
Barn 255FP 375"/35 gr =1847
Barn 255FP 377"/35 gr =1892
CP260LFNGC 380"/36 gr =1989

The low sigma and small group with the Horn indicates that they may be slugging up somewhat.
The 377 Barnes grouped much better than the 375 version though the Cast Performance is the overall winner by a long shot. Pardon the pun.
As you discovered, OAL is best kept well controlled.

And yes, I still have all my fingers, and the cases extract effortlessly, though I consider the above loads max in my rifle.

Has anyone tried 32 Special cartridges in a 38-55?

How about 30-30 in a 32 Spec.?

There are stupid people and there are people that are stupid. Argue semantics all day long and it still ends up the same.

All this post does is point up the fact that...no matter what is said...it will be mis-construed, mis-interpreted, mis-read, mis-understood and mis-spelled.

No matter the amount of rhetoric or how well or poorly presented,after a few people have uttered their tripe, it turns into a bunch of people running around with their puds in one hand and a keyboard in the other, beating both to death and not getting any satisfaction from either.

Some mindless people think it is great fun to keep the pot boiling either by jerking others around, others by showing just how knowledgeable they are, and/or others by not having anything positive to do with their time and living on the net vicariously.

Oh, by the way, I have a NEF 45-70 Buffalo Classic 32" barrel that runs 300 gr Sierra, Speer or Hornady bullets well over 2600 fps using several loads out of the 2006 Hodgdon Manual at Marlin levergun pressures. When I posted that fact on one site people went nuts. It was patiently obvious that NO ONE who went berserk really read or understood the words. I pointed out ALL the facts yet those without a clue started jaw flapping. I don't post ANY reloading information what-so-ever now.

Way too many people don't have a real clue about reloading, a limted understanding of the basic principles of how to go about reloading, yet will argue incessantly using their limited knowledge, interminably...while the "experts" do the opposite...argue interminably from an elitist position...neither perform any kind of usefull service to and for the reloading community...just to their own highly inflated egos.

Wonder which ones will go to hammering in response to this post? I would bet on all.

Forgot to mention, Buffalo Bore makes a 38-55+P load listed as 255gr cast @ 1950 f/s. Must have rifles blowing up left and right.

Dear Dave King;

I don't know if you're still around, but I thought I'd tell you my experience with this question.

20 years ago, handloaders increasingly loaded the 45 Colt cartridge to warmer levels than the old SAAMI specs for the cartridge. When this happened, we heard those handloaders were crazy. Eventually, though, the loads were standardized in 'modern firearms', and it became normalized within the shooting community. Reloading manuals included the data, all of them eventually accepting it. There are very few people interested in your question so it is unlikely the 38/55 warm loads will ever become standardized.

There is no difference in the situation regarding the 38/55 and the 375 We are talking about pretty much sraight walled cartridges that headspace on the rim. In a modern firearm, I decided to load the Marlin 336 chambered in 38/55 more robustly than the ancient SAAMI specs. It is a personal decision.

Of course there are insults waiting for one who goes off the path. All the reloading manuals tell you the two cartridges are not the same, and the 375 loadings are not safe in 38/55 rifles, making no distinction between modern rifles and ancient ones.
Thus naysayers have the documentation to back up their position. There is no point in discussing this. They'll tell you you'll blow your rifle and go straight to hades- exactly what Bowen and Linebaugh and Keith and others were told when they warmed the 45 Colt. And they'll tell you exactly what nay sayers to the warmed up loads for the 45/70 were told 20 years ago when that ancient round was reexamined. All the loading manuals at the time said not to warm the 45/70, that the rifles and brass could not take it. Well, we see where that went; there are now 3 or even 4 levels of load data for the 45/70, depending upon shooting platform.
Ken Waters is not bad company to be in today.

I would watch the brass carefully. I've experienced no problem, and have been doing this for years. I'm the quality assurance for my decision, and as I said, it is a personal decision. Your
original posts raised all the relevant points.


People urging caution regarding this matter are correct. We've all seen reloaders who just can't leave a cartridge alone, and push it past its limits. For years the 45 Colt was used as an example- every other reloading manual showing a blown cylinder out of a Ruger blackhawk. Reloading manuals are our Bibles. We trust them. There is a plentitude of people proposing unsafe reloading practises, so we don't allow change to the reloading manuals unless it is very carefully thought out and turns the test of time.

35/55 warm loads will not have a sufficient 'lobbying' group to move the peg forward.

It is because of old rifles that Marlin made the 450 marlin. It is because of old rifles that Winchester made the 375 Winchester.

I will not make any reccomendation for others, but I've reached my own decisions regarding the 38/55 and warmer loads.

It is a difficult topic and I don't anticipate a resolution.

Does anyone here have experience loading the 32 H&R mag to equivelent SAAMI pressures of the 357 and 41, 44 mag in a modern handgun? Does anyone say that is unsafe and dangerous? It is a common practise among knowledgeable re-loaders. It cannot be done in a HR firearm. I doubt anyone is going to publish data nor reccomend it.

Are many aware that the 32/20 was loaded hot in suitable firearms for the NRA hunter shooting classification? Was this a bad thing? Several reloading manuals used to have this data.

There is even warmed data for the 45 acp!!

The truth is the 38/55 simply does not have enough fans to get this issue seen clearly.

I think the bottom line to this and other reloading questions are, "Who is doing the reloading?"

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