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
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<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
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<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!
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<br>Thanks,
<br>Charlie
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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.
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<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.
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<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.
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<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.
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<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.
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<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.
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<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?
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<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.
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<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.
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<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.
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<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