Home Forums Lever Action Central Big Bore Levers Subsonic Loads for the 45-70?

I have a Marlin stainless guide gun with the barrel shortened to 16 inches and threaded. I plan to put my sons and grandson in the good spots this season while I do some covert meat hunting. I am still developing a 405 grain load using H4895. Hodgdon has determined that H4895 lends itself to reduced loads. The company recommends starting at 60% of the maximum published charge for a given cartridge/bullet combination and working up from there.

I loaded five sets of cartridges with charges progressing one grain per set yesterday. My quest is to find the largest charge that will be "whisper quiet" using my Silencerco Hybrid Suppressor.

Now, if I can just find some time and dry weather to try them out!

Do any of you have experience developing and shooting subsonic 45-70 rounds through a suppressor.

T.S.

Me having suppressor experience, and loving the 45/70 here are my thoughts. Whatever powder you use, don't go below 30% case fill. Use a stout crimp to encourage complete powder burning. I have some data if you need it, don't use cast bullets with a suppressor, a lot of centerfire suppressors aren't user serviceable or cleanable. At your target range, say 50 yards, put your cellphone in the area of the target, and record a video of the shot, see if the sounds are acceptable to you.

Here is 308, Sierra 180gr roundnose that I moly coated. About 950 fps at 50 yards.

.308 Subsonic

Thanks for the advice Jeff. Yes, the 30% of case capacity caution is why I am not using hot pistol powders like some. The smallest charge I have loaded for testing is 30 grains. I'm pretty sure I will be able to go higher than that and still maintain subsonic velocities.

I have a 30-30 load using a 220 grain jacketed Hornady FPs that is that is whisper quiet. By whisper quiet, I mean the muzzle report is a "poof" and the bullet impact is a loud "thwack".Also, I purchased some Atomic brand subsonics for my suppressed 308 (175 grain Sierra Matchking) and they are whisper quiet as well. I'm hoping for the same with these 405 grain jacketed flat nose bullets.

Have you been able to find a 45-70 load that is "whisper quiet" when suppressed?

T.S.

12.0 gr Unique and a 405gr cast RNFP gives 1050 fps in my 18.5" Marlin.

Good info here:

http://www.gmdr.com/lever/lowveldata.htm

Thanks Montana. - T.S.

That's going to be hard to beat. My records show 10 grs of Unique, or 11 grs of Herco, with the 405 jacketed, no filler. This was a Marlin Guide gun. Make sure the bullet is going out the barrel, every time as you test them this low. I home moly my suppressor bullets to lube them.

LOL!!!! So far, the loud smack of the bullet tells me it got out. :-) I also need to make sure the bullet is stabilized and printing round holes with the given load before screwing on my suppressor.

Jeff, what is the advantage of lubing the bullet? Are you moly coating lead?

T.S.

If it were me I'd look to use something like a RCBS 45-500 FN without a GC and get that bullet coated if using a suppressor. Cast bullets have a lot less friction compared to jacketed bullets.

At 1000 fps it is not going to be loud, though a longer barrel would help if not using a suppressor. That particular bullet is designed to fit and function in the Marlin but importantly it takes up a lot of internal space, making reliable sub sonic loads easier to achieve.

Roger that JFE. - T.S.

Just don't brush off a bullet/round you can't account for without checking the bore. No, I am moly coating jacketed. Back in the Stone age ...'70's. We found that the true "cat sneeze" bullet should be lubed to BE SURE it cleared the barrel, we used Crisco. To moly coat, I'm using a small rock tumbler, molybdenum disulfide, and airgun BB's, tumbling them for two hours or so gives lube for the bullet and bore; the accuracy with lubed bullets show improvement also.

This +1; you'll have a much easier and safer time working out a good load with a cast bullet, especially if it's of appropriate hardness and not the excessively hard commercial alloys that are so common.

Also, this is very important - when developing subsonic reduced loads, work DOWN in powder charge, not up! You aren't worried about an upper pressure limit, you're trying to stay above the lower limit of sticking a bullet in the bore, so you work down towards that instead of guessing at a low charge when you don't know where the sticking point is. That happens at much higher velocity for jacketed bullets than for cast. As velocity decreases, you'll notice velocity variation of the jacketed bullets will go nuts shortly before you stick bullets. Cast bullets should be fine down to 600 fps or less, but your jacketed bullet may stick as high as 800-900 fps in that big 45/70 case.

It might be overly optimistic to expect "whisper quiet" from a 16" 45/70; that's a lot harder to do in the big bore than in medium/small bores. 30+ grain powder charges won't help you in that goal either; that's why most experienced suppressed/subsonic handloaders look to small charges of fast pistol powders.

Russel I did something similar last year and cut my 1895GS to 16" for use with a Hybrid. H4895 will work but running the numbers on Quickload, the max charge of H4895 will result in only 66% of the powder being burned in the barrel. The rest has to go somewhere and what doesn't get shot out will wind up in your action and suppressor. I have found Unique and Trail Boss are much better suited for subsonic loads and result in 100% burn for that length barrel. Of the two, I get quieter loads using TB.

If you can find them the Remington 405 JSPs work really well though lead bullets work fine if you powder coat them first. This prevents sticky waxy lubes from building up inside your can since the Hybrid cannot be taken apart for cleaning. I have had good luck with the Lee 405 bullet for subsonic 45-70 and 458 Socom. If you want to shoot me a PM I can share whatever subsonic load data I have for the 45-70. FWIW I just finished my 44 SBR build so am getting ready to convert another 1895GS to a 12" SBR which should make for easier handling with a can in place. Even at 16" I find the gun somewhat unwieldy and nose heavy with a can.

12 grains of Trail Boss with a 405 homecast tumble lubed. Velocity 980 fps. Good accuracy. Not shot through a can.

Thanks guys.

I have a hollow base mold for the 45 muzzleloader. Wondered about it in the 45-70? Maybe at the low velocity for a suppressed marlin turn it around, cavity forward, powdercoat and use TB for the load. 100 yards or less I'm guessing. May or may not stabilize. I have had too may projects to get to this one.

That bullet is a tumble lube wadcutter style of bullet. Was thinking of dead soft lead to cast them.

rusty, I don't have enough experience with this to answer your question or even express an opinion. Sorry. - T.S.

Sounds like a good experiment. Cast some up and see what shakes out. But I don't have approval on my Hybrid can yet. ATF is slow to slower at times. Would get me moving to know I was picking up the Silencerco. And of course the threading isn't done yet. Will require some smithing. Have the desire to set up the Marlin as a threaded takedown. Then the loads can be experimented with. Rusty.

I tried some loads of 405 Remington FNSP using large rifle CCI primers over 15.2 grains of Unique yesterday. I had several Failures to Fire even though the primers were clearly struck hard. Plus, among those that fired I had sticky extraction. The primers were not flattened and the brass looked OK but I think I was experiencing high pressure spikes. I put those loads away and will disassemble them this week. I am going to stick with my H4895 loads. They shoot dirty like Remington's trapdoor loads but are well-mannered and appear accurate.

T.S.

AA5744 lends itself to light loadsçl as well. 15 to 20 grains works nicely in my Buffalo Classic.

I had forgotten 5744, thanks the _shootist.

Trailboss..........Unique

I experienced powder bridging throwing Unique in a rifle powder measure. I was trickling the last bit of powder so it was obvious right away. I broke out the old school Lee dippers, and dipped/trickled.

I don't know if you may have possibly been having powder bridging issues, but I have never had inconsistent ignition or indicators of pressure using Unique with the 405gr cast bullets.

Pretty versatile powder.

Anyone done further shooting?

Montana, the loads were correct and consistent. Since they were so light, I trickled each one. But, thanks for the caution. I have not tried any more loads with Unique. I'm staying with H4895. It's not "cat sneeze" but it's pretty quiet.

Thanks to all for your contributions to this thread!

T.S.

tag

I would never ever shoot any lubed cast bullets in a Hybrid....

Loading for sub-sonic rule of thumb is minimum 60% of available case volume with bullet seated as close to 100% powder burn in your barrel length. A accumulation of too much unburnt powder in your suppressor can cause a secondary detonation.

I've done a lot of sub-sonic work with the 450 Bushmaster and 45-70....best powder is Trail Boss 100% burn in a couple inches of barrel. Load densities start at 70% you can load up to 100% and do not compress powder.

Some great bullets available for sub-sonic....Makers Bullets....https://makerbullets.com/products.php?cat=3&scri=64
Outlaw Bullets...http://www.outlawstatebullets.com/4.html
Remington 405 gr. cup-core

In your 45-70 a Remington 405 gr. cup-core with 13 gr. of Trail Boss is sub-sonic at 1010 fps in a 16" barrel at 70 F 785' elevation 30% humidity, .5 gr. more depending on conditions may be above sub-sonic. Its very quit had a guy at the range ask me what kind of air rifle it was....lol... Ruger #1

Thanks. That's good info!

T.S.

I have the 500 grain RCBS mold. I haven't been able to get that bullet to stabilize in my Marlins below about 1200 fps. Maybe my alloy...

I doubt the alloy has anything to do with it. It really just boils down to velocity and twist rate.

Old thread, but my experience with the new 410 gr Hornady Sub-X bullet is that it takes 14.5 gr of Unique to push it at 1050 fps. I tried 10.5, 11, 11.5 … and so on until I got the magic number.

This is in the Henry X 45-70. Accuracy is good. I’m using a 4x scope and getting 2” @ 100 yards. I’d like better, but let’s be honest … I’m not shooting much farther that 125 yards with this load due to a massive drop after 100. Of course, YMMV.

I was just shooting Hornady Subsonic in my 45-70 last week. Very pleasant and very accurate

Reloads? Or their loaded ammo?

Factory ammo

Many years ago I bought an old Lyman 255 grain mold that actually threw bullets some where close to .456 in one cavity and .457 in the other. Both leaded my pistol barrel like crazy, so rather then throwing the mold away I tried the bullets in my 45=70 with light charged of Unique. Worked like a charm with 13 grains od Unique with a 2 inch square of TP or Kleenex to hold the power in place. Little noise, no recoils, accurate and 50 rounds didn't cost much, and was a lot of fun. Youngsters liked shooting a big bore that didn't bite.

Unique isn't position sensitive. No tampon needed. I still tilt the firearm vertically before commencing fire.

Liking ~14 gn with a 405 cast.

Never tried not using the wad of paper in the 45-70 for very light loads.

I have been loading Unique in the 45-70 since 1975 and never had a misfire, and never used a filler/wad.

All the way down to 12 grains.

Just goes to show one man's meat is another's poison. You wouldn't think this would be the case...but other variables enter into the picture.

It's why we experiment....

Those loads are "unobtainium" right now, I would like to try some in my new Marlin Trapper/Hybrid46 combo. I ordered the 410gr Sub-X bullets to roll my own and have Unique or AA5744 to work with, have not been able to locate Trailboss locally.

Trailboss in 458WM with 405gn projectiles is subsonic.

I'd avoid Unique - in straight wall cases it will sometimes ring the chamber, irrespective of wad or not. The free space will generate localised pressure spikes for some reason - kinda like what happens with free space in blackpowder loads.

I am missing something here.. why sub-sonic? I was never in favor of reduced ballistics because of the noise.

In my case, suppressor use. Those big flatnosed bullets make a hellofa sonic boom

Was finally able to work up a couple loads for my 1895 Trapper/Hybrid. It took 25 grains of Accurate 5477 to get the Hornady 410 grain Sub-X to 1060 fps. Also tried some Unique with the Missouri bullet co. coated 405 grain hard cast. Was kinda surprised when only 12 grains got it to about 1070 fps. Would like to try some Trail Boss but haven’t been able to find any local and not willing to pay high shipping fees. Even though they’re hearing safe, they still make quite a bit of racket going down range. The Hybrid is my first experience with a centerfire suppressor and the 45 calibers (Govt and Bushmaster) are not nearly as quiet as the 350 Legend I’ve tried it with so far.

Unique...pressure spikes...ringed chambers? Color me skeptical. Unique was invented for greatly reduced loads in straight wall BP cartridges in 1890...and been in continuous production since. A 130 year track record. In every case I have heard of damaged rifles with Unique, people ignored published data and used case fillers. 40 years and counting, I have used Unique with great success in .32-40, .38-55, .44-77 and of course .45-70.

I just read a match banned over powder wads for loads using smokeless powder due to the prevelence of pressure issues using that method. Trying to find where I read it so I can link it.


**Found it.............The Matthew Quigley match. I copied and pasted their explanatiion below:


Please take a few minutes and look at the new Safety Page on our website. It details specific procedures now required at the Quigley Match in an effort to prevent any further shooter self-induced injuries caused by rifle failures like we have experienced twice in the last several years. Possibly the most controversial is banning over-powder wads of any sort when using double-base smokeless powder (AA 5744 being the most popular in use). Shooter acknowledgement of the procedures and confirmation of compliance will be part of the registration process for the match. Shooters will be required to register prior to any practice on the range. A technical paper describing issues of concern has been published on the Safety Page also.

Safety Issues of Concern

Note: This is not a directive on how to reload. It is a note of caution and a warning about some of the dangers. If you reload for yourself or others, you do so at your own risk.

The last few years it has become increasingly clear that certain reloading practices are increasing the dangers inherent is our sport of rifle shooting. We will try to outline some of these practices and dangers so you are made aware of them. Not all of these are fully understood since the science is a difficult one to observe and the effects are likely variable due to even minute changes in the causing condition, equipment and other parts of the equation.

Three basic types of powder are used in our sport although they are often listed as two (black powder and smokeless). These basic types are more directly labeled as black powder (and substitute), single-base smokeless (nitrocellulose) and double base smokeless (which has an added buffered nitroglycerine component).

The primary problem we have been experiencing has been unexpected loss of control of the propellant combustion.

Powder manufacturers have experimented greatly in this regard and, with loaded ammunition provided by them, have maintained a cautious approach with a generous (though not large) margin for safety. They, by demand, also supply reloading supplies to their customers and by various means have supplied safety guidelines for the use of their product. This is where we come into the picture. We reload because the volume of our shooting demands cost savings.

The problem is showing up as damaged firearms and some explosions that can injure and/or kill people. There is always an inherent danger in our sport, but the practices of some are making it more so.
A number of rifles have emerged with the dreaded chamber ring. This is often first noticed as sticking cases and, when inspecting the cases, a noticeable, protruding ring is found around the case approximately where the base of the bullet would be inside the case. Carrying this inspection further shows a ring in the wall of the chamber at this point. This chamber ring is an indication of being close to the pressures that will burst the gun.

So far, virtually all of these known instances have been with the use of double-based powder and usually (admittedly) using a wad in the case that held the powder back against the primer. These are usually lighter loads in large cases.

The facts are that the manufacturers have sold this powder carefully marked as double-based and have made efforts to inform the user not to use an over-powder wad with it (card wad, cotton wad, polyester fiber wad or other types). Some have cautioned not to use reduced charges (below a recommended minimum charge).

The use of a wad over the powder provides an air space between the ignited powder and the base of the bullet. The powder is ignited and burns from behind, pushing the unburned powder in front of the burn. The unburned powder gains momentum and gathers heat. The air is compressed but the bullet remains stationary. Then, the unburned powder slams into the base of the bullet. The powder is sensitive to temperature and impact. At this point, both are provided and a new rate of burn and energy release comes into play. It’s best thought of as a new, highly volatile explosion, usually called detonation, of the unburned powder.

The manufacturer has carefully tested the powder in single-cavity chambers and has provided guidelines for such use, but the separated cavity with the wad and associated airspace hasn’t been (and presently can’t be) fully accounted for. The pressures generated will displace solid steel by extrusion, shear or rupture depending on the strength of the steel and the pressure generated by the exploding force. Small increases in powder charge or resistance to the movement of the bullet can be the difference.
The difference between a chamber ring and a burst barrel may be only a couple of grains of the unburned powder before the detonation. Double-based powder is very useful without the wad. With an over-powder wad, it’s a dangerous commodity – the air gap being the problem and not the wad itself. Air compresses a long way before much pressure is generated. A case full of air compressed down to almost nothing won’t move a bullet.

It should be noted that a wad isn’t needed to supply the air gap. Simply pointing a lightly loaded rifle straight up (providing a volume of air space between the powder and the bullet without a wad) will do that and, therefore, a rifle loaded with a chamber-ringing below load data level of powder will ring the chamber without the presence of a wad.

All gun powders are temperature and percussion-sensitive but single-based powder (nitrocellulose) is much less sensitive than double-based powders and within reason can be controlled.
The use of a wad and air gap with single-based powders is much less apt to damage or destroy a firearm than with double-based powders, but it can be done with improper load data and careless reloading procedures.

Black powder is also very sensitive to heat and percussion and does cause this phenomenon of sudden increase in pressure in the presence of an air gap, but in equal quantities develops much less pressure than either type of smokeless powder. However, too much of any gunpowder will blow up and destroy a firearm.

The air gap phenomenon described above does occur with black powder, although with a relatively milder detonation. With certain loads it can blow up a gun and has done so in the past. The use of a small quantity of smokeless powder or finer grade of black powder (4Fg or dust) to ignite a normal load of black powder will cause the coarser powder to burn with a greater intensity and pressure and present the danger of burst rifles. An included air gap will also add to the pressure – sometimes greatly so.

An overcharge of any powder can blow up a gun and many things can and do cause pressure increases. Some of these are: heavier bullets, longer bullets, bullets engraved into the rifling, harder bullets, dirty bullets, bullets with inclusions, obstructions in the bore (even soft things like mud or a bug, sometimes even water), hotter primers, cases too long for the chamber and wrong powder. Since some shooters are pushing the envelope of pressure already, any of the aforementioned items can push the pressures beyond what can be contained, and an unexpected, uncontrolled explosion will result.
Another consideration is the strength of the steel of the barrel and the rifle action. Modern steels are in general much stronger than antique steels, but some modern steels are stronger than others. Be aware of the strength of your rifle.

Be safe and stay within known guidelines. We want you all to enjoy the sport of shooting for many years to come.

Never had a chamber ring in a my rifle or shotgun, so I skipped the rest of the article.

Interesting, thanks for that. I didn't see reference in particular of the ringing issue to the use of reduced loads using fast burning powders ie pistol powders. There's plenty of cases where ringing isn't an issue with reduced loads using fast rifle powders with spaces and/or fillers. The only ringing issues I've heard of were reduced loads with pistol powders in straight wall cases with or without wads.

Graeme Wright wrote a little bit about it also in his "Shooting the British Double Rifle" - I'll have to reread it.

Lehigh Defense has some subsonic data for their 325gr bullets. Just as an FYI. Hope it helps.

https://lehighdefense.com/458-diameter-325-grain-xtreme-defense-bullets-50-count.html

Google "trans sonic instability".

Anyone try Shooters World, Buffalo Rifle?

I have been using Unique behind a 410 gr Hornady Sub-X. It’s pretty quiet w the Hybrid 46, but nothing like a 300 BLK with 4227 or H110 and an Omega. That gun is insane how quiet it is.

I got an email reply from Shooters World saying you can safely use Buffalo Rifle at reduced loads. Kind of like Trail Boss.

Anyone try it?

Also, who has experience with Unique vs H4895? Is one quieter than the other?

My load, over a chronograph is 14.5 Unique at almost exactly 1050fps.

Maybe my expectations weren’t reasonable with the 45-70 subsonics.

I've read it's almost identical to 5744, which is what I use for my 410gr Sub-X load. I used Unique for my 405gr cast bullet loads since I'm running low on 5744. I haven't been able to find 5744 or Trail Boss locally so I might have to pick up some Buffalo Rifle if I see it, looks to be more available than the first two.

H4895 is borderline too slow for full-up loads in the 45-70, although you can reduce it, you are screwing up. H4198 is the sweet spot burn rate - I run 405gr jsp @1800fps Guide Gun. When I have loaded subsonic, I used fast pistol powders, no fillers, CAS data as provided in the link earlier.

Here's the link again
http://www.gmdr.com/lever/lowveldata.htm

OUnless the air temp is 15°f, 1070fps is not supersonic.

The CAS data link you were given shows the sweet spot at 11 grains of Unique for a 405gr cast bullet. If you want to run even slower then go up in bullet weight - I used to run 500gr at 750fps.

Did not mean to infer those loads were supersonic, they weren't. Only pointing out that even at subsonic speeds the .45 calibers are not exactly whisper quiet. Much louder than smaller bores to my ears.

I have loaded for velocity, killing effect, recoil avoidance, etc, but never for noise reduction or very low velocity. In fact, higher velocity has often been the objective to provide a flatter trajectory or more killing effect on the target animal.

May I ask why the effort to keep rifle velocity subsonic?

A loud magnum revolver has made my ears ring, no rifle shot by me has done that.

The point of a suppressor is to quiet the muzzle blast, it can do nothing for the sonic boom the bullet makes. Shooting unsuppressed that "boom" is masked by, or blended with, the muzzle blast and not as discernible. To make the shot even quieter shooting suppressed, the bullet velocity needs to be kept under the speed of sound. That's kinda the mechanics of it.
The reason people want to quiet their shooting varies and I can only speak for myself. I like to shoot, but I'm not fortunate to live in a secluded area and I have neighbors a few hundred feet on either side and a mile behind. I'm not a fan of packing up equipment and driving 5-15 miles to one of the local ranges, unpacking, paying a fee and dealing with the inevitable know-it-all idiots and the "range nazi". I do have a safe shooting spot out back with a large dirt berm, but it does nothing to abate the noise. I have good neighbors and respect their right to the same peace and quiet I enjoy, so I limit my shooting of "noisy" firearms to only a few rounds a year. After I got my first rimfire suppressor, I discovered the joy of just walking out back with my .22 handguns and running hundreds of rounds through them, without hearing protection, and not disturbing the neighborhood. After finally receiving my Hybrid 46, I'm hoping to be able to replicate that to a degree with some of my centerfire rifles.
My reason, YMMV

tmitch,
Thank you for the best non- military and non- SAS explanation that I have seen.

I too live on a few acres in the country (with my south fence being the city limits ) and where I can legally shoot varmints and such with a pistol or small caliber rifle, but where regular target practice could disturb neighbors. And my larger caliber center fire pistols and rifles really need a backstop.
There is a gun range 10 miles one direction and a friends farm 20 miles in another direction where I go as needed , but it would be nice to be able to practice on my property. Guess that I should just move the family and horses further out in the country.

Loading a .45-70 to "be quiet". We all thought that was pretty...funny. When I want a firearm to be "quieter", I put on ear pro.

With ~13gn of Unique with a 405gn cast you get the two part report of a Winchester from the old Western movies.

Unique is NOT position-sensitive, so fillers/wads are nonsense.

11-13r of Trail Boss is quiet(er) with 400/405gr bullets.