Extra short barrel?

[seb]

Gentlemen,

What kind of accuracy (say in MOA) do I expect from 12.5" .308 and 10.5" .223 barrel?

- This is for hunting gun & probably some plinking at the range.
- Bolt gun, no barrel length & suppressor restriction here.
- Interchange barrels & bolts.
- With integral suppressor (1.75"x17" or so)...hopefully I could also interchange barrels just by hand tightening at the range...?
- Want the gun to be as short as possible.

This might sound "over-confident" or stupid...can I expect, say 3" (+/-) accuracy @ 300 yds?
Assuming all things done properly.

Have seen some in youtube but never have an SBR so far.

Thanks & Best Wishes,
seb.

 

[Minesweeper3433]

I am in the process now of getting an 18" 308 together were I cut the suppressor mount into the end of the barrel. Barrel is a 1.250 straight from krieger 1-8twist 5 groove rifling non ratchet type. Hoping it is accurate with 185 bergers and my subsonic loads as well all in the same platform. Was going to go shorter than it is but to be honest I didn't need it and you can't hunt with SBR's here.

My LWRC RPER 12" shoots quite well for being what it is but that isn't a good representation of bolt gun accuracy out of same length barrel. Accuracy has very little to do with barrel length in regards to getting worse with shortness. With a good barrel chambered right 3" at 300 should be very obtainable even with factory loads.

 

[Toolbreaker]

Just thinking out loud, but with the proper load workup for the barrel length, I'd think that it might be more accurate than the same rifle with a longer barrel. Just from sheer rigidity with less barrel "whip". Of course, environmental effects come into play with the lower velocity obtained, so that part may be a wash in the end.

 

[284driver]

The only thing I've lost with short barrels is velocity.

 

[hogan]

Why the 1:8 twist for a .308win?
Is this a suppressor thing?
One in 11 would be excellent for up to 200gr unless you are doing some super-long VLD bullet have to single-load for....

Seems like a super-fast twist and might be detrimental to all but the thickest bullet jackets. Really don't get into real thick bullet jackets until go .338 or larger diameter. I recall the early Nosler 155s comps, made with J-4 jackets would come apart in flight. J-4 Very Highly Regarded jacket for .30cal match semi-custom bullets... 11.25 is the standard twist with 1:10 for the heavy VLDs... Curious as to why the 1:8????

thanks in advance...

I am in the process now of getting an 18" 308 together were I cut the suppressor mount into the end of the barrel. Barrel is a 1.250 straight from krieger 1-8twist 5 groove rifling non ratchet type. Hoping it is accurate with 185 bergers and my subsonic loads as well all in the same platform. Was going to go shorter than it is but to be honest I didn't need it and you can't hunt with SBR's here.

My LWRC RPER 12" shoots quite well for being what it is but that isn't a good representation of bolt gun accuracy out of same length barrel. Accuracy has very little to do with barrel length in regards to getting worse with shortness. With a good barrel chambered right 3" at 300 should be very obtainable even with factory loads.

 

[Minesweeper3433]

Need a faster twist to accurately stabilize heavy bullets in subsonic applications. I can get a 1-10 to stabilize 190grn subsonic loads reliably but 200 grn and up class bullets go sideways pretty quick. The rifle will primarily be used with subsonic loads almost full time and supersonic shooting will be a secondary function for the rifle. Plus I have read of much faster twists being made to work well with 308's with only a few negative side effects such as higher wind deflection and spin drift. So I figure a 1-8 would work fine. Plus I got a good deal.

 

[d.id]

I have a 1in8 16" 308 win.
Standard 43.0 varget / lapua / f210m / 178 amax can shoot inside 1/2 moa out 600 but starts to open up after that.
My best subsonic is a 12 grains of trailboss with 225 hornady match, roughly 1 moa maybe 1.25 out to 200...not yet tested farther.
I do not need to chase velocity and therefor love some short rifles but would not bother going into SBR specs with the 308..........not to shed 3.5" and expect going that far down would probably be counter productive for supersonic suppression anyway.
.
I saw good potential from heavy amax and vld but they could not run effectively at mag length in this gun. My last short action.

 

[seb]

Thanks for the replies gentlemen!
Sounds that I'm "on the right track".
My .308 barrel twist is 1:10, would try 168/180 gr and probably 155 gr pills, too. The .223 barrel is 1:7.7, just have 69 gr pills to try.
Wouldn't be subsonic load, I don't have proper powders here. The integral suppressor is just to make it more quite. Will build from scratch.
I would be very happy already if the rifle could shoot around 1 m.o.a. (=hopefully under 3" @ 300 yds, 5 shots)... that's all I need for this gun.
Cheers,
seb.