Best barrel length for precision AR

[Cal-gun Fan]

What do you guys think would be the best barrel length for a bull-barrel .223 AR-15? It probably will be an RRA upper.

We probably won't have an opportunity, at least not on a regular basis, to shoot beyond 400 yards, and would like to hunt with the rifle as well. So what do you guys think? 16, 18, or 20 inch barrel? Thanks!

 

[Squidward]

I don't hunt.. But My stag 16 inch Barrel is good out to 400 yards on a 12 inch gong. So I don't think you need a heavy or long barrel. What I do think is important, if you want precision, is the quality of the barrel and the twist rate. At typical .223 velocities, a 1:9 twist will stabilize bullet lengths equivalent to lead-core bullets of 40 to 73 grains in weight; quite a spread!

As I said, I don't hunt so I'd say start with the ammo you intend to use for hunting, find a quality barrel and get it with the appropriate twist rate. People more knowledgeable than me like Noveske and LMT.

 

[JHenry]

20 in" would be your best if your looking for a good trade off of additional accuracy and lost mobility

 

[madcratebuilder]

The quality of the barrel and chamber is more important than the length. Most precision AR's are around 20" +/-. At your 400 yd range you well not see much difference from a good 16" vs a good 20". I have a 12.5" Colt barrel that shoots very nicely out to 200yds.

 

[jmr40]

For a general purpose AR used for plinking, informal shooting and self defense I like a lightweight 16" barrel. When I tried to set up my 1st AR for more precision shooting I went with a 16" heavy barrel. After a few years I got tired of the muzzle blast and sold that upper and went to an upper with 20" target barrel.

This gun is much heavier and longer than my other AR's which have lightweight 16" barrels, but is more pleasant to shoot. It may be just a bit more accurate than my 16" target barrel, but I doubt it is the extra 4" of barrel. I rarely shoot farther than 300 yards, but if I ever do those extra 4" could make a difference at longer ranges because of slightly better velocity.

Just my opinion, but I don't think you'd gain enough velocity going to anything longer than 20" to be worth the trouble.

 

[68wj]

I like a good 20" .223 barrel unless you need it to be shorter.

 

[Redlg155]

I've been a fan of 18" barrels since my last build. Manueverable enough to use in CQB but long enough to provide the characteristics and stability a longer barrel offers. I've been nothing but happy with my DPMS MK1 barrel.

Longer barrels do not offer any additional accuracy, only longer sight radius and mor offhand stability.

 

[gotigers]

20" HBAR, Stainless, .223 Wylde chamber, 1:8 twist. White Oak, Fulton Amory (Criterion blanks), Kreiger, shaw, Lothar Walther. This combo will be more accurate than you can shoot.

 

[451 Detonics]

If you are going to use a free float tube I would go 21 3/4 without a flash hider and an 11 degree target crown.

 

[mortablunt]

20 inch barrel is the best of the options you listed.

 

[MachIVshooter]

20" heavy.

A 24" will gain a small amount of velocity, but IMO, not enough to justify the additional length and weight. 20" is optimal for most .223 loads.

A 16" or 18" can be just as accurate in a vacuum, but the lower velocity means environment has more time to act on the bullet in flight in the real world. At longer ranges, wind may not be (probably isn't) constant from muzzle to target, which means it cannot be accounted for 100%. The more time a crosswind is pushing on a bullet, the farther off target that bullet will be. All else being equal, faster bullets are more accurate.

 

[Cal-gun Fan]

We currently have a 20 inch HBAR upper, but its not a target rifle upper. Believe that its a J&T Distributing upper, but it has no markings on it. Thats kind of why I was thinking the 16 or 18 inch barrel.

 

[Zerodefect]

410 SS 18" with rifle length gas, but more of a straight medium contour. Not HBAR, but still plenty heavy.

Any bigger than that and I'd rather have a larger purpose built bolt action rifle with a heavier caliber.

 

[kfgk14]

look at Bravo Company Mfg's SS410 barrels. I have their 16" mid-length, and I've shot their 18" rifle-length a lot. Both are laser-accurate, sub-MOA out to 400 yards. the 16" I have was turned down to about .700 under the handguards with deep fluting, the 18" was just fluted and contoured for an OPS collar and brake.

A 16" is plenty for what you want to do, an 18" would stretch the range to about 600 meters, perhaps a bit more if you do your part with good glass and ammo.

Check these uppers out from BCM:
http://www.bravocompanyusa.com/BCM-SS410-16-Mid-Length-Upper-Receiver-Group-p/bcm-urg-mid16%20ss410%20vtrx13.htm

http://www.bravocompanyusa.com/BCM-SS410-18-Rifle-Length-Upper-Receiver-Group-p/bcm-urg-18%20ss410%20vtrx13.htm

Both offer modular handguards (sling, bipod, illumination if you're hunting varmints and hogs at night), flat top uppers and rails, and SS410 barrels.
They're about $100 more than comparable RRA Varmint uppers, but they're far lighter and equally if not more accurate. You'll appreciate the lightness when you hunt with the rifle.

Bravo Company sells lowers, but building your own is more fun, allows you to know how it went together, what parts went in, and will save you money over buying a lower at the gun shop just to replace the stock/trigger/pistol grip later. Also, you'll have all the necessary tools to do maintenance yourself (replacing worn springs, sears, etc.).

 

[Cal-gun Fan]

We've got a Colt lower, don't need that, just looking to get a new upper

 

[kfgk14]

Oh, I see. Good choice on the Colt lower, by the way.

 

[Cal-gun Fan]

Thanks, its my dad's though
This is kinda a christmas present thing for him, and not sure if he looks at this website or not, so I was trying to play it down a bit.

edit: I really like those BCM uppers too by the way. Thats not something I had thought of!

 

[kfgk14]

The guys at BCM are top-notch, customer service is awesome.

 

[FMJMIKE]

My 16" stainless steel barreled Bravo Company upper is pretty darn accurate. Almost puts every bullet in same hole at 50 yards.

 

[Redlg155]

A 16" or 18" can be just as accurate in a vacuum, but the lower velocity means environment has more time to act on the bullet in flight in the real world.

Velocity is not the answer to all. In the "real" world there are just too many variables in play that affect accuracy. In some instances pushing a heavier bullet at lower velocities can be more accurate, hence the popularity of heavier. 223 match loads. I doubt that many long range shooters use the ultra fast light nullets.

 

[MachIVshooter]

Velocity is not the answer to all. In the "real" world there are just too many variables in play that affect accuracy. In some instances pushing a heavier bullet at lower velocities can be more accurate, hence the popularity of heavier. 223 match loads. I doubt that many long range shooters use the ultra fast light nullets.

Never said it was.

But I guess you chose to ignore the part where I said:

All else being equal, faster bullets are more accurate.

Of course we're talking rifles here. Handgun bullets that transcend the sonic barrier before reaching the target suffer. So do rifle bullets, but since they all start out super-sonic, the ones that stay super-sonic further out are more accurate. So, I repeat (concerning rifles, which is the subject here), all else being equal, faster bullets are more accurate.

 

[redneck2]

Rifle accuracy boils down to quality of the loads and quality of the barrel. I have a 24" barrel on mine that shoots WAY under MOA. It shoots incredible groups with loads that are supposedly less than optimum.

Bench rest shooters use short barrels on their rail guns.

Length is the least of your variables IMO

 

[MachIVshooter]

Bench rest shooters use short barrels on their rail guns

18" is the minimum length for both IBS and NBRSA.

http://www.benchrest.com/FAQ/5.7.shtml

 

[Redlg155]

"all else being equal " may be a valid assumption in a controlled situation, but nothing is equal in real life. I can take 2 identical rifles, with identical barrel manufacturers and ammo selection and chances are that one of these rifles will be more accurate with any given load.

I'm guessing that Schuetzen shooters would also agree with lower velocities.

 

[MachIVshooter]

"all else being equal " may be a valid assumption in a controlled situation, but nothing is equal in real life. I can take 2 identical rifles, with identical barrel manufacturers and ammo selection and chances are that one of these rifles will be more accurate with any given load.

I don't know why you chose to argue this point, but I promise you, it's a losing battle.

I'm gonna say it one more time; The faster the bullet, the less time environment has to act on it to alter it's flight path. I am NOT saying that a lighter, faster bullet is more accurate than a heavier and slower one.

Let's say it's an 80 gr. Sierra matchking we're playing with. Let's use two muzzle velocities; 2,600 and 3,000 FPS. I plugged it in with my pre-loaded 8,000 ft altitude, 40*f temp and 29.9 Baro for hunting conditions. At 1,000 yards, the bullet that started at 2,600 FPS will have a 1.663 second flight time, and a 10 MPH constant crosswind will push it 90.1". The same bullet driven at 3,000 FPS will have a 1.41 second flight time to 1,000 yards and the same wind will only push it 72.6". That's a quarter second of flight time and foot and a half less wind drift with a mild breeze. Take into account that wind speed across a 1,000 yard distance is unlikely to be constant, your margin or error with changes in windspeed is going to be that much greater with the slower bullet.

This was the entire driving concept behind the .408 Chey-Tac. Look it up.