What barrel profile for 12.5" SBR?

[raider1v1]

I need to order the barrel for my 12.5" sbr build soon and cant decide what profile to go with.

The two for me to choose from are the govt profile as seen here:

http://www.rainierarms.com/?page=shop/detail&product_id=3108

or the 'heavier' thicker profile. its not a full bull barrel, but somewhat in between like this

http://www.rainierarms.com/?page=shop/detail&product_id=1207

Im not sure if i would need the extra weight and thickness to handle the heat from being suppressed and shot quite a bit. Right now im leaning towards the thicker profile barrel.

 

[BCP]

Re: What barrel profile for 12.5" SBR?

If you plan on putting lots and lots of rounds through the barrel at a time I'd get the chrome lined. For all other purposes I'd get the 1:7 twist stainless.

Also I'd get a 10.5".

 

[popeye089]

Re: What barrel profile for 12.5" SBR?

I would go thicker mainly because of the heat factor. You figure common knowledge states that as the barrel heats POA & POI change. You are already giving up some advantages with a shorter barrel to gain some advantages in other areas.

 

[raider1v1]

Re: What barrel profile for 12.5" SBR?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">If you plan on putting lots and lots of rounds through the barrel at a time I'd get the chrome lined. For all other purposes I'd get the 1:7 twist stainless.

Also I'd get a 10.5". </div></div>

any particular brand/maker for the barrel? it seems that most of the thicker profiles are SS vs chrome lined. i wont be pumping mags through it, so i dont know how big of a deal it will be.

my stamp is for a 12.5" that will be clearing sometime in the next few weeks. i think id go shorter for other uppers but for now, ill just go with the 12.5

 

[raider1v1]

Re: What barrel profile for 12.5" SBR?

also, is there any issue with getting the AMBI extensions if im not running a LH upper?

 

[BCP]

Re: What barrel profile for 12.5" SBR?

If it were me I would look for a stainless, 1:7 twist m4 feedramps wylde or 556 chamber. Second place would be 1:8 twist stainless and third place would be chrome lined 1:7 556 chamber.

Longer barrels I like 1:8 twist but everything I've read makes me think that shorter barrels do a little better with a faster twist comparatively.

FWIW the 10.5" pistol builds I've fired have performed almost like a rifle. So buying a good barrel wouldn't be a waste in a 12.5". It'll probably be damn near as accurate as a good 18" out to 300 or so.

edit: no idea on ambi extension I always go M4 feedramps on 223 and 308. brand Rainier stuff is all good, White Oak is good, Daniel Defense, Noveske, LMT.

 

[sawgunner2001]

Re: What barrel profile for 12.5" SBR?

If/when I ever get around to finishing a trust and submitting myself to the pains of NFA wait times for an SBR, I want that fucker light. I don't care about POA/POI changes because the ranges that I'd use an SBR at, it won't matter. I'd probably also want it chrome lined to last a little longer. I'd give a rats ass about accuracy. If the gun shoots 2 MOA, awesome. Or even 3, who cares. Thats a 3" target at 100yds getting drilled every time. Good enough for me.

If you plan on using an SBR for 800yd sniper comps, get a stainless bull barrel and make sure that bitch is free floated. You're gonna need it

 

[raider1v1]

Re: What barrel profile for 12.5" SBR?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">If it were me I would look for a stainless, 1:7 twist m4 feedramps wylde or 556 chamber. Second place would be 1:8 twist stainless and third place would be chrome lined 1:7 556 chamber.

Longer barrels I like 1:8 twist but everything I've read makes me think that shorter barrels do a little better with a faster twist comparatively.

FWIW the 10.5" pistol builds I've fired have performed almost like a rifle. So buying a good barrel wouldn't be a waste in a 12.5". It'll probably be damn near as accurate as a good 18" out to 300 or so.

edit: no idea on ambi extension I always go M4 feedramps on 223 and 308. brand Rainier stuff is all good, White Oak is good, Daniel Defense, Noveske, LMT. </div></div>

so any of those companies are going to be good. i think for the 12.5" ill be fine.

so im set on that now, the thicker barrel, the weight difference between the two profiles isnt that big of a deal.

so now, if you will permit me more questions, is the twist rate. is the 1:7 vs the 1:8 going to be that big of a difference? What will my gr limitations be between the two?

also this barrel - http://www.rainierarms.com/?page=shop/detail&product_id=1895

the 223 wylde chamber, is that OK to shoot 5.56 through or no?

 

[BCP]

Re: What barrel profile for 12.5" SBR?

Only grain limitation I can think of is once in a blue moon someone shooting service rifle finds out that their 1:8 twist barrel doesn't like 80gr sierras. Really really rare though.

Wylde chamber is fine for 556. I shot lots of 62 grain milsurp through mine without a problem.

My ultra match 16" is great with 75 grain hornady loaded to mag length. I don't see why a 12.5" wouldn't be but you could call Rainier with your concerns about bullet weight and accuracy.

 

[leadbullet]

Re: What barrel profile for 12.5" SBR?

I would go for as light weight as possible, so a standard M4 profile is more than enough to last a lot of ammo.

 

[raider1v1]

Re: What barrel profile for 12.5" SBR?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">Only grain limitation I can think of is once in a blue moon someone shooting service rifle finds out that their 1:8 twist barrel doesn't like 80gr sierras. Really really rare though.

Wylde chamber is fine for 556. I shot lots of 62 grain milsurp through mine without a problem.

My ultra match 16" is great with 75 grain hornady loaded to mag length. I don't see why a 12.5" wouldn't be but you could call Rainier with your concerns about bullet weight and accuracy.

yah ill have to give them a call. i think right now im leaning to the WOA due to its price vs the others. they are out of the m4 but from what i can read on the AMBI its got feed ramps modified for LH receivers, it should be OK for normal use but ill need to confirm w/ them.

</div></div>

 

[raider1v1]

Re: What barrel profile for 12.5" SBR?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: attherange</div><div class="ubbcode-body">I would go for as light weight as possible, so a standard M4 profile is more than enough to last a lot of ammo. </div></div>

after looking at the weights, its only a couple oz different. so ill take whats in stock and in budget.

 

[SPDSNYPR]

Re: What barrel profile for 12.5" SBR?

Lighter is better. The whole point of an SBR is a short, light handy package. Once you start adding optics and lights, those few ounces add up.

And I think the 12.5" bbl is a great compromise length. More dwell time, and a bit more velocity. Still very compact.

 

[chainring]

Re: What barrel profile for 12.5" SBR?

Noveske 12.5 inch medium