AR barrel advice for using 50-55gr 223 ammo

[Ghillie Zen]

Need some experienced advice. I'm looking to build an AR upper purely dedicated to shooting 50-55 grain 223 ammo accurately from 100-300yds.

Would like to keep barrel around 16".

What barrel brand/type, length and twist rate would best fit my needs?

Thanks!

 

[CanPopper]

Re: AR barrel advice for using 50-55gr 223 ammo

Barrel type: bull contour cut rifled barrel made by one of the fine barrel makers such as Krieger, Rock, Shielen, Satern, etc.

Length: you answered it yourself

Twist rate: 1:10 to 1:12 (note 1:9 is good for the 60gr bullets)

 

[eli polite]

Re: AR barrel advice for using 50-55gr 223 ammo

try black hole weaponry i have one of there 16 barrels with poly3 and it does very well

 

[Howie Feltersnatch]

Re: AR barrel advice for using 50-55gr 223 ammo

I agree with 9 or 10 twist. Anything faster than that and will create accuracy problems. If you go with a 9 twist you do have the option to also shoot the heavier 60 gr's if you wanted to.

 

[salmonaxe]

Re: AR barrel advice for using 50-55gr 223 ammo

I'm partial to Compass Lake Engineering. They'll chamber a better AR barrel from krieger blank than krieger will. Get it with a matched bolt.

Something akin to an SPR contour but shortened to 16" will be both accurate and handy.

 

[Ghillie Zen]

Re: AR barrel advice for using 50-55gr 223 ammo

some good suggestions.

so, what would be a fair estimate to have a pof upper shipped/sent back and fitted with a descent 16" 1:12 twist barrel with standard threading? Part costs, shipping and labor?

also, will the pof's gas system cause issues for fitting a barrel? maybe add to cost?

there seems like a lot of options for barrel services out there, but which ones tend to have a rep for both quality and good turnaround?

 

[carbinero]

Re: AR barrel advice for using 50-55gr 223 ammo

I have no accuracy problems with 1:7 twist and 55 grain. From what I've read, that becomes an issue more with varmint bullets in lighter weights, although I've never tried 'em. Noveske N4 16" mid-length.

 

[Hellbender]

Re: AR barrel advice for using 50-55gr 223 ammo

Even a 1 in 9 twist can frag very light jacketed (Blitz, etc.) 50 grain bullets at high velocity.

A 10 or 12 twist is optimal with 50-55 gr bullets.

 

[MKSMN]

Re: AR barrel advice for using 50-55gr 223 ammo

Don't get a 1/12. Unless you plan on shooting extremely lightweight (40 gr.?) varmint bullets, there's no point to it. Most of the good stuff for an AR now is the heavier 60 to 77 grain, especially in match-grade ammunition. I could see a 1/12 for a dedicated bolt varmint rifle, but why in an AR?

1/9 is a decent compromise that I've never had an issue with, but I like 1/7 better. The faster the twist, generally the better for heavier bullets, and slower is better for the flyweight stuff. Check out some of the data in previous posts on similar topics. Google is your friend here.

Hell, ask the military why they switched from the 1/12 to 1/7.

 

[Greg Langelius *]

Re: AR barrel advice for using 50-55gr 223 ammo

If the 5.56 case had more capacity I'd give the 1:7' twist some more worry, but it doesn't and I don't. My only concern about twist would be about blowing up some bullets, and I don't think that's a terribly serious concern with the 5.56 in a regular AR barrel length. For most of the world, a 1:9" or a 1:7" should be fine. If I was trying to pick off flies at phenomenal distances, I wouldn't be using an AR anyway.

OTOH, for an accuracy priority at 100-300yd with an AR, I'd be most comfortable with a 1:12" twist, and I'd go longer than 16" if I could. I honestly believe that if your 1:12" AR won't shoot sweetly with a 52gr SMK and 26.0gr of Varget, there's something wrong with the gun.

Greg

 

[355sigfan]

Re: AR barrel advice for using 50-55gr 223 ammo

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ErikTaylor</div><div class="ubbcode-body">I agree with 9 or 10 twist. Anything faster than that and will create accuracy problems. If you go with a 9 twist you do have the option to also shoot the heavier 60 gr's if you wanted to. </div></div>
That is incorrect in my experience. The 1/7 1/8 shoot the 50 grain and 55 grain pills just fine. The 1/9 is ok up to about 69 grains and some 1/9 guns will handle the heavier bullets some won't.

A 52 grain SMK reload fired in my 1/7 twist Noveske.

The average with this load was 1.20 at 100 yards. One of the best loads for this carbine.

Basically its an internet myth that the faster twist guns will not shoot lighter bullets accurately. What can happen is with really light bullets (45 grains or so) you can have the bullet spin itself apart. I have seen that.
Pat

 

[carbinero]

Re: AR barrel advice for using 50-55gr 223 ammo

http://www.m4carbine.net/showthread.php?t=63446

"A semi-automatic AR-15 is not going to shoot as accurately as a precision bolt-gun, but today’s precision AR-15s are capable of a level of accuracy that is truly outstanding for a semi-automatic rifle. The 10-shot group pictured below was fired from one of my Krieger barreled semi-automatic AR-15s from a bench-rest at a distance of 100 yards. The barrel has a 1:7.7” twist. I used Sierra 55 grain BlitzKings that were hand-loaded on a Dillon XL-650 progressive press. The load was developed using the Accuracy Node Detection Technique. The group has an extreme spread of 0.452”."

 

[Greg Langelius *]

Re: AR barrel advice for using 50-55gr 223 ammo

Re-reading, all I have ever heard about CLE confirms my assessment that if I were in the market for an AR, they'd be my main choice.

What <span style="font-style: italic">I'd</span> do is bring these questions to CLE, and get their best guestimate of what will work. If anybody knows accurate AR's, and anybody knows <span style="font-style: italic">their</span> AR's, it would be them.

I think they understand that the best gun for a customer is the one that makes the customer happy. I think they can manage that task.

Greg

 

[bustin]

Re: AR barrel advice for using 50-55gr 223 ammo

big difference in what is considered accurate.
some consider 1MOA, some try to beat 1/4 MOA.
Any true match grade AR should do 1/2MOA with a good scope, trigger and driver.

OP, A true match grade 1 in 9 twist will work fine, if you call 1MOA good any SS RRA or Armalite NM may work, if you want 1/2 MOA then get a true custom not a production barrel from a big manufacture that calls them NM barrels.