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Precision Rifle Gear Optimal barrel length for a 6mm BRA?

smooth

Private
Minuteman
Apr 8, 2018
43
25
Hey folks. I have a friend who is doing a custom build 6BRA, He's planning on a finished length for his barrel to be at 29". Seems a bit too long to me. Is there any ballisical advantage for that length of Barrel?

Thanks in advanced..
 
Essentially it's free velocity at the expense of weight/balance/awkwardness. I have a 30" tube on my 6.5-06AI for this reason, it doesn't have to be super mobile and gives me the velocity I want without pushing the limits of everything else.
 
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What’s the gun for? Does he run a suppressor?

26-32 inches, depending.
Field matches, long range targets in the mountains. Recreational shooting. I know he is looking at velocity gain in that length of barrel. I guess I'm curious at what point does barrel length peak in velocity performance.

EDIT: Not suppressed.
 
30 inches is probably about right for something that is closer to a benchrest gun. I think 26 is perfect for a more mobile requirement.

assuming you are shooting 105 gn-class bullets (103-108 gns, for example), there seems to be a sweet spot for accuracy right around 2850-2900 fps. You can get that with 26 inches of barrel, possibly shorter. So, that’s my ideal length for a gun that needs to negotiate barricades and in which I shoot 105 hybrids exclusively. If you want to shoot 115s and you expect 3100 fps, probably 30 inches or more.
 
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free speed and weight out front

it really isnt that big of a deal being a little longer. no worse than a 24" plus a can

ive run 31" barrels in PRS. it's nbd

there's a definite advantage to going longer than 24/26"
 
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free speed and weight out front

it really isnt that big of a deal being a little longer. no worse than a 24" plus a can

ive run 31" barrels in PRS. it's nbd

there's a definite advantage to going longer than 24/26"
weight out front is not always a good thing...and the speed past 26"-28" in these small cases is not huge...i wanted to run H4350 in my current barrel...25" i can get 2850ish with a slightly compressed load in peterson brass....my smith runs a 28" barrel he can get 2880ish but he can get .4g more powder in his lapua brass slightly compressed...for me the other 3" is not worth it.

ive ran from 22" out to 28" and for me he perfect all round length is 25"....its short enough to be maneuverable and long enough that im not giving up much velocity....a 25" 1.25" straight taper in an MDT ACC with full internals steel bag rider and rear weight balances slightly front heavy about 2" in front of the mag well and weighs in at 23.2lbs no mag or bipod.
 
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2" in front of the magwell is maybe balanced or still slightly rear heavy except for maybe a pint sized GC underneath

considering most stocks/chassis are rear heavy. extra 2" of barrel may mean buying 1 less weight kit for a chassis or getting a perfect balance with a McMillan/Manners/Foundation

no doubt 24/25/26" is more maneuverable. i shoot a 24" 223 (didnt choose barrel length). but i dont notice the difference when shooting stages
 
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I run a 28" 6BRA with a hellfire brake and a 27" 6.5x47 with a sidewinder brake - Both wind up really close in total length and both are just about as long as I could go and still fit in a pelican 1750 without a folder. Both balance exactly the same because they are in ACCs and I can easily adjust weight placement to make them balance the same. My weight placement on the two rifles is not the same, but the balance is.

I guess I look at it a little differently than others. I dont really see much benefit to cutting an extra inch or two off the barrel on a heavy match gun. I ran plenty of 26" barrels in the past and I dont really feel a difference in terms of length and moving the gun around. But I do have a little more weight, little more speed, the ability to set them back if I need to and not get stupid short.. so why not? I think its really more of a preference thing than anything. They all work, just pick what you like and run it.
 
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5B77990E-073F-4A98-8445-8F9EE9302CD9.jpeg

One of @b6graham rifles. He likes them Thicc
 
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I run 26” in Heavy Varmint (whatever the manufacturer du jour is calling a 1.25”x5” shank and a single taper to 1” at 27”…I think Bartlein calls it a #9). With an Ultra 7 out front it’s annoyingly long anytime the barrel has to go out through a port/window. Might do the next at 24”. With just the brake, 26” is fine.
 

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