Home Forums Hunting & Shooting Custom Rifles & Wildcats Been doing a little more experimenting.........

For a long time I have wondered about how barrel length affected velocity. I had always been told you need a certain length barrel for certain calibers. I have read when folks compared one gun to another with different lengths but I always thought that was not an apples to apples comparision. So I did a few test myself.
<br>All these were Shilen barrels. I used the same brass through out the whole test. All weighed to with 1 grain. Bullets were tested on the Juenke machine. Powder charges were weighed to .1 grain. The same rest, chronograph, Redding press, primers all from the same lot, bullets for the same box, same lathe, same crowning tool, same cutoff tool, and each rifle done from start to finish on the same day. Ambient temperature was the same because I shoot from inside the shop. I held the rifle the same way on the rest every time. I shot ten rounds first to break in the barrel. Then cleaned with Sweets and fired one fouling shot. Then shot five rounds and took the average. I used a midrange load fron the Nosler book, not too hot but certainly not a reduced load. Here is what I got.
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<br>22-250 Hodgdon 380 34 grains Federal GM210M Remington brass 55 grain Ballistic Tip
<br>27 inches 3469 fps
<br>26 3451
<br>25 3425
<br>24 3407
<br>56 fps from highest to lowest
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<br>270 Winchester Hodgdon 4350 54 grains Federal GM210M Winchester brass 130 grain Sierra
<br>27 inches 3115 fps
<br>26 3093
<br>25 3071
<br>24 3054
<br>23 3035
<br>22 3027
<br>21 3001
<br>114 fps from highest to lowest
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<br>300 Winchester mag Federal GM215M Winchester brass 74 grains of Reloder 22 180 grain Partition
<br>27 inches 3055 fps
<br>26 3031
<br>25 3024
<br>24 3003
<br>23 2984
<br>22 2960
<br>95 fps from highest to lowest
<br>
<br>340 Weatherby Federal GM215M 250 grain Sierra
<br> 81 grains Reloder 22 Wby brass
<br>27 inches 2837 fps
<br>26 2817
<br>25 2809
<br>24 2791
<br>23 2777
<br>22 2755
<br>21 2731
<br>106 fps from highest to lowest
<br>
<br>I think I will do a little more thinking before I recommend a barrel length in the future. What do you folks think ?
<br>Charlie

Thanks for posting that. Just about the time I think I know a little bit about rifles someone shows me how wrong I am. I sure did think there would be a much bigger spread, at least with the magnums.

Makes it hard for me to want anything over 22" in a rifle intended to be carried!
<br>
<br>Thanks,
<br>Charlie
<br>

Charlie, thanks for posting that... you've concisely proved what I've suspected for years. The only reason I can see for a long barrel is that some cartridges are definately quieter in longer barrels... I won't own those cartridges anyway.
<br>
<br>Mike, I don't (and won't) own a rifel with a barrel over 22"... except if I get another 22-250 which will wear a 23 or 24" tube. All but one of my four 338 WM's have had 22" bbl's.
<br>
<br>Brad

Interesting data Mr Sisk. I would be curious to see the same test with a heavy charge( max) of slow-for-cartridge powder and a heavy for caliber bullet.
<br>
<br>MM

MM
<br> I have a 300 Wby mag that should be finished about the middle of next week. I am going to use some 220 grain bullets with Hodgdon 870 and Hodgdon 4895 to see if there is much difference.
<br>Charlie

Charlie,
<br>
<br> I'll look forward to your results. One thing that put my mind in the direction I was thinking is the reports folks post with the Light Magnum ammo. I've seen some pretty good differences from 22" to 26" in the 30-06, with the 180gr LM ammo.
<br>
<br> I've been loading 63 gr of RL-22 under 190 Sierra MK moly, in Norma cases, and getting average 2903 fps from my 26" Douglas barrel. quickload estimated 2907 fps and 54,000 CUP for this load. I would be curious to try this one in a 22" 30-06 for comparison.
<br>
<br> This load is 3 gr over book max. but given moly bullets, a slow for cartridge powder, and lower max book pressure for 30-06, I am not surprised this shows no signs of high pressure.
<br>
<br> I've gotten responses bordering on disbelief on my results with this load (the 30-06 is only supposed to beat the .308 by 100fps). I feel the 26" bbl, powder an bullet combo bring the 30-06 to a near optimum for cartridge performance.
<br>
<br>MM

MM
<br>Looks like you are ready for hunting season !!!
<br>That combo with a good 2.5 x 8 scope will certainly put meat on the table.
<br>Charlie

Thanks for the info:
<br>
<br>This will really help my thinking about my next project which is intended to be a sub 5lb (scoped) BP rifle. I was thinking 21" now maybe I'll go 19" or less?
<br>
<br>I'm thinking maybe a 'cat on a 250 sav. case in a short Sako or Wby Varmintmaster. Action will have to go on a diet of course.
<br>
<br>JimF

i would also be very interested in reading what you come up w/ using max/near max charges of slow burning powders - especially in a magnum of some flavor.
<br>
<br>your initial results show me that 22" is all that is required...but before i start lopping barrels down, i'd be interested in seeing what you come up with.
<br>
<br>

I see the light! Thanks for sharing your research with us. And just in time before I have my mountan rifle twisted up. Since I am locked into building on a long action, I was thinking of going with a 25-06. I was concerned about bobing the barrel back on that caliber, not wanting to give up too much of it's speed. Now I will rest easy and have the barrel cut to a length that offers good ballance. Thanks again Charlie.

Thanks for taking the time to post the results from your hard work and time. Makes me really change my train of thought on 'dream' projects.
<br>
<br>JimF- I'd be greatly interested to hear how that project turns out.

Charlie,
<br>
<br>Thanks for posting the info. I too would be intersted in seeing further comparision between a variety of powders and projectiles.
<br>
<br>Blaine

Carlie, would you be able to tell us what the difference in felt recoil is in those various barrel changes ? I am looking to build a light weight gun but being of medium frame recoil is a big issue to me . I have been shooting a Sako deluxe 7rem mag for years and love the gun all 11 scoped pounds of it ,but its to dam heavy to carry up the mountain anymore. If I am unable to have a reasonable rate of recoil I will change calibers possibly to a 270wsm or similar after more reaserch. Not sold on what other caliber to switch to if nessasary but would like something that shoots as flat as my 7 mag. Thank you for your help and willingness to share the results of your test with us.

Wildone
<br>I couldnt tell much difference if any in the recoil. Its hard to judge . I dont have any way of measuring it either. If I were you I would consider a 7mm Rem mag in a 7 or 7 1\2 pound gun with a 22 or 23 inch barrel. That 11 pounds gets heavy after a while. Depending on what you are hunting and how light you want to go a 7mm-08 may be a good choice. Give me some more info and I will get back with you.
<br>Charlie

Charlie, I am leaving to go Bou hunting I'll get back to you when I get back . Dean

Update
I tried this same experiment on a 257 Roberts and a 338 Win mag and got the same results. I can post the results if anyone is interested.
Charlie

Charlie,
Myself and others would be interested in the 338 Win mag. What podwer and bullets did you try? Thanks, MtnHtr

I'd love to see all of them, since so many people seem to think that is not the way things work. Thanks for the insight.

Here is the info about the 338 Win and the 257 Roberts.
338 Win mag
Winchester brass
Federal GM215M primers
Reloder 19....73 grains
250 grain Partitions
27 inches.....2806 fps
26 inches.....2787 fps
25 inches.....2761 fps
24 inches.....2743 fps
23 inches.....2716 fps
22 inches.....2697 fps
21 inches.....2676 fps
20 inches.....2656 fps
150 fps from 27 inches to 21 inches

257 Roberts
Federal GM210M primers
Remington brass
H-4350....45 grains
120 grain Partitions
27 inches.....2860 fps
26 inches.....2834 fps
26 inches.....2815 fps
25 inches.....2815 fps
24 inches.....2798 fps
23 inches.....2775 fps
22 inches.....2760 fps
21 inches.....2739 fps
20 inches.....2717 fps
143 fps from 27 inches to 20 inches
I want to test this on the next 450 Marlin I build and on a 222 Remington. If I get the same results with those, in my mind the test is over. I think this will be enough data to support the findings. Are there any folks out there who have a degree in this sort of thing ? Maybe explain how many data points would be needed to be able to say this would work with the majority of calibers ? Someone with experience in statistical(spell check) quality control ?
Charlie

Thanks Charlie,

Appreciate the 338WM experiment. Since I chopped mine from 26 inches, to 22 inches, those were the figures I was interested in personally. Looks like about a 90fps velocity decrease between the two lengths. Not too big a loss, for having 4 fewer inches of barrel. I'll take that trade anyday! <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />

Charlie,
Thank you also. I had mine chopped also from 26" to 23.25" for a loss of 64fps. RL19 is the powder I plan on using also so you hit her on the nose. MtnHtr

Charlie,

Had to take a semester of statistics but didn't pay much attention. If I get some time tomorrow I'll break out the text book and see if I can help you out.

Conventional wisdom has velocity change at about 25 fps per inch. You got about 20 and I will use your data now.

We do get carried away with long barrels for hunting rifles and they don't handle as well besides the weight.

Don_Martin
This wasnt meant to be the gospel. I know the test I performed were done properly but there may be variables that I havent considered. I used a lot of Partitions and a Hornady may work differently, I just dont know. Different primers with different powders may have an effect also. Could a three land barrel versus an eight land barrel make a difference ? I dont think so but again I dont know. I am curious if a 30 caliber barrel that is .3080 would loose the same speed as a .3085 barel would. Would crimping versus not crimping make a difference ? What about leade angle and freebore ? What would happen with a paper-patched lead bullet ? Boat-tail versus flat-base ? I dont think any of these things will make all that much difference. I think barrels from one to the next will vary more . I have decided that on my own rifles I will use this data for fact but I will let the customer make the decision until I have time to do more testing. Has anyone else tried these things ? If anyone here would know I bet Mr Howell would . Sir, what do you think ?
Charlie

Sounds like you've got more testing to do Charlie

I guess I have disagree about longer barrels not handling as well as shorter barrels. In my opinion,a sporter weight 24" barrel seems to balance best and be the easiest to shoot off-hand on most guns. I have handled many custom big-bores with relatively heavy 24" barrels on Mauser and Model 70 actions. To me, with a proper stock, these big guns point like fine shotguns (although heavy ones). I just bought my wife a Rem. M7; the short, lightweight barrel on that gun handles horribly for me (hard to quickly acquire the target and hard to hold steady off-hand). I guess that's why the manufacturers make all sort of different guns, and men like Charlie will make whatever you want. Everyone's a little different.

Charlie, thanks for the excellent post.

MrMD,

In my experiance a big game rifle with light ends handles best for all around use.

Shooting from the standing position or offhand might be broken down into taking a shot at a stationary target where there is time to aim. For this purpose a rifle that has more weight in the barrel is better for the reasons that you gave. However shooting from standing, for me at least, seems to be at moving game and then the light barreled rifle is much faster to get on target and to move with the target.

If there is time to stand and aim for a moment there may be time to get into a steadier postion also.

Mr. Sisk, re:your question on .3080 vs. .3085 bores

In my .30 cal. BR guns, I haven't seen any real velocity loss as we've reduced the barrel length. The .30 cal. Liljas I use usually run right at .2998-.3000 and are three groove with both 1:15 and 1:17 twists using a leade angle of 1.5 degrees. The case is based on the 308 Lapua and is shortened to hold an average of 48.0 gr. of water.

I believe the throat angle, freebore, number of grooves, and neck tension have as much to do with a barrels velocity as anything..within reason of course.

My gunsmith just finished a 250 Savage Ackley Improved for me. From a 22" barrel, the 75 VMaxes will go 3680 and the 87 gr. Sierra flat based bullet 3400. A short throat, snug bore (especially on a .25, as most bullets measure around .2565-.2568 for the .257 bore) and an efficient case sure does wonders for velocities.

Neat experiment..thanks for the info. -Al.

Bump
Thanks for the info. Makes my decision easier

Very cool Mr. Sisk. Lots of folks talk about theoretical outcomes...you've actually done the tests and drawn your own conclusions.

Excellent old thread. Whatever happened to Charlie Sisk?

Probably working to pay the bills.. 'tis hunting season as well..

I talked to him about 6 weeks ago about a rifle project. He told me he was going to post some data here soon on Bore Coated barrels.

Seeing Charlie Sisk posting again is nice.
Wish I would see Talus, AFP and If It Flies It Dies. Those guys welcomed me to the fire when I went by the login name youngbuckaz86. A lot of great people on this campfire.

Interesting to see the difference in FPS between 22 and 24 inch tube but also 26 and 22 inch tubes. I am looking at the data on the 270 since it would be close to the 25-06 I am building but also the 257 Roberts. The rifle won't be losing much with that 22 inch tube i'm gonna buy for it.

Kique

Folks
Charlie Sisk is alive and well. Working every day, trying to stay afloat. Still building 300 Win mags 50% of the time. I keep telling myself I'm going to start posting more, but I've got more work than I can say grace over.
Charlie

Why do you think those 300 win mags are so popular....

Marking this thread. Good stuff. Thank you

That's the most important part !!

Very interesting, Charlie... I appreicate you publishing this info. I've got a 24" barrel on a 336-06 I think could likely be trimmed back 2-4"...

After owning an 18" .270Win I can tell you there are other benifits to a longer barrel other than FPS. I personally like the way a 22"-24" lightweight barrel balances.

Never was into the sub six pound rifle fad anyway.

Great info but wonder how some of the speed demons would react to the same treatment. Cartridges like the .257WBY or the .264WN, better or worse?

Terry

Terry Happy Birthday!

My thoughts exactly, on all points. My rifles all weigh 9-12lbs and have 25-18 inch barrels and I love 'em all. I have long wanted to do this experiemnt with those cartridges you mentioned as well as the STW, RUM and (Pick your caliber)/378 rounds. I suspect that the results would be different, but could not say for sure. Would sure be worth trying it out. If someone wants to fund such a project I would do the work.

TC1
I didnt test the two you mentioned, but the 300 RUM , I tested with H870 and H4895. Same results as a 308 or 223 or any others. In my opinion and testing, modern smokeless gunpowder burns like modern smokeless gunpowder. No amount of case shape, advertising, endorsements, etc, has any effect. Dont take that as the gospel, thats just what the chronograph and strain gages tell me.
Charlie

Charlie -- rather than posting the average velocity at each bbl length I think it would be interesting, and maybe more informative, if you posted the velocity for each shot at each bbl length.

Where the actual, individual velocities "clump" might be more informative.

Fascinating! I would have bet folding money that the 300RUM with H870 or other slow burning powders would have shown larger velocity gains with the long barrels than would have a more pedestrian cartridge using powders of moderate dosage and burn rates.

So, how does one determine now an optimum barrel length for a given cartridge and bullet? Surely we are not suggesting 16 inch barreled 257STW's. Not being a smart aleck, genuinely curious and want to think this through or perhaps begin creating a formla. Someting like with X size bore and Y size case capacity velocities are optimal and will not sufffer significant velocity loss vs (what to date has been the gold standard for uberfast rifles) 26 inches or longer, at Z length of tube.

How many times have we read, both ere and on the gun rags, "the 264 WinMAg with a 22 inch barrel is just a loud 270" Seems to not be so! Or "better hold out for a 257WBY with a 26 inch barrel, the 24 inch tube on the Vanguard and Remington will not allow the 'ol Roy to do what it was designed to do"

What to make of all this is the million dollar question.

Balance and blast count.

That said, whether an 18 or 28" bbl, if you put a good bullet thru vitals, the animal will never know.

No doubt I too like shorter than longer, but want a balance of the variables that get affected.

Charlie Sisk,
What a tremendous amount of work and foresight went into this experiment. We all owe you a lifetime of gratitude. All the gun writers in the world couldn't answer the question in 100 years better than you did. Thank you is inadequate, but THANK YOU!

+100

Now, give us an optimal barrel length formula!

Thanks Charlie, it's alway's been a theory of mine that 99% of the powder in a cartridge is consumed in the first 1" of the barrel anyway and the rest of the barrel is only a means for the pressure created in the first inch to react on the bullet. I've been taken to task for this several times but still think I'm right about it.


Terry

I Just came up with a brilliant idea! a 2 inch barreleld snubie revolver in 300 RUM! Titanium and scandium parts.... Wow, that would stop a bad guy in a hurry

I would suggest engraving your name, address, and spouses contact info on top of the barrel so when they dig it out of your head they know who to contact.

Good idea! See, when two great minds work together great plans come about.

I was joshin ya, of course. I mostly agree on the gunpowder gets all burnt up quicklike, but the gasses do expand for a while after. The big question is, for how long and at what pressures and gas speeds and for how far along the barrel.

Maybe the throat erosion of a well used rifle reveals the powder and gas burn??? Some worse than others. Seems like the barrels don't wear as much the further you get from the chamber, and it doesn't seem like the bullet speed changing would account for all the difference. Any thoughts?

I think that you are right on the money with that, and I have put forth that idea for a long time as well. Think about it, if it was bullet SPEED that wore out a barrel, then the MUZZLE end of it would be worn down the fastest! As it is, the predominant theory and logical one at that is that the throat erosion is caused form unburned and burning powder being blown down the tube like flaming and mega hot sandpaper particles. That, along with hot gases acting as a cutting torch. From about 2 inches or so on down, we have only expanding gases working on the base of the bullet and for the most part negligible wear all the way to the muzzle even though the bullet might be reaching 4000 fps out there. If someone ever solves the puzzle of barrel wear at the throat with high intensity cartridges a lot of financial success will come their way, I would guess. Maybe Roy Weatherby had it right with freeboring those high velocity rifles so as to 'pre wear' the most affectd areas and not lose rifling or have it go gunnybag since there weren't any there to begin with.

Here is another "thank you,Charlie" and good job
Could you see any obvious difference in noise/muzzle blast with the shorter lengths?
Eventhough we know we should wear ear protection hunting, a lot of us don't.
Huh? What did you say?

The 300 Rum with an 18 inch barrel has quite a blast. Didnt seem to make much difference using H4895 or H870. I was wearing ear plugs and muffs, not using a decibal meter.
Charlie

+1. Excellent info!

I have a spreadsheet that gives the optimum barrel time for any barrel, given length. The time is in mili-seconds, and you need a program like QuickLoad to translate that into FPS for any given load. Send me a PM and I will e-mail it to you, if you wish. Or, you can go to here: Linky to read more about it.
It is not an exact science, but it does cut down on load development time, and shots fired.

Thanks to Charlie Sisk for all of his work on the barrel length project. Very valuable information!

R.

Doesn't seem like 20 years ago...

Goes by pretty fast doesn't it.
Glad your still here.
dave

CharlieSisk,

Based on your observations, and experience what would be an optimal barrel length for both the .308 and 30-06 cartridges, if the person was building a precision-oriented hunting rifle with longer shots expected due to the terrain/environment?

Charlie Sisk' info is very good & relevant years later, & I thank him for his time & effort.

For more like it, rifleshooter.com has cut quite a few barrels for several cartridges & reported. The articles are hard to find for me, but if I scroll down the page & click on pic of 1" long barrel drops, or one of a chop saw, I can find several test.

Still love seeing a well done comparison especially when it requires hard work most people won’t or can’t do. Even better when it sets a bit of old dogma off in a corner where it should be.

Yes and still valid today, and we all thank you for all you did then, and still do.
I was turning 47 when you did that, where does the time go?

What I do on my own rifles is this....I build leaving the barrel at the 28 inch blank length. Then finish the rifle, add scope, and dummy rounds in magazine. Then throw it up to my shoulder. Then cut off a bit. Throw it back up. Cut a little more until it feels the way I want. After that, I don't measure.
Charlie

I was thinking of asking a question about feel and balance, but it was answered with this post. I do better with 24" barrels (and 26" for that matter) than 22". They seem to balance better and hang steadier than the shorter ones for me. Maybe it is because of my build at 6'4" and 240 lbs. I do have a 28" med. hvy. barrel on a #1 that is too much of a good thing but from the bench or bipods.

I also prefer a 24" to 26" inch barrel simply due to a preference for a "weight forward" feel...

tag for later

Thanks Charlie for some good info