HD/CQB/Carbine Class AR15 Barrel Profile

[Doc7]

Hello,

Do AR platforms have the problem with "whippiness" (not regarding accuracy - regarding handling) that one sees with light weight hunting rifle builds? I see next to no comments on this online unlike say a discussion of a Featherweight profile vs Pacnor Sporter etc when rebarreling a Savage or whatnot.

I am considering a build with either a 14.5" pinned/welded or 16" in either a Faxon Gunner or Faxon Pencil profile.

Is there anything suboptimal about handling characteristics for the shortest and lightest of the 4, a 14.5" Pencil? I know in a hunting rifle this would sound like a practically unmanageable length.

 

[FL-NC]

I don't think so. The first rifle I was issued (M16A1) and carbine (CAR 15 variant) had the pencil barrels. If anything, they help "handling" Actually firing is a different story, at least to me. I like the M4 or "heavy" profile 16" barrels if for no other reason than that they are front-heavy and do better for tables/drills where multiple rounds are fired very quickly, not to mention heat factors.

 

[Zerodefect]

14.5" Larue Predator .300blk barrel is the best carbine I've shot to date. Very light swing weight. AR's don't get whippy. Lighter the nose for carbine training the better. BCM's enhanced lightweight barrels and uppers are another choice if you want a chrome lined barrel.

Keep in mind that if you'll be using a 1x red dot and the stock set short for "nose to the charging handle". With the stock set that short, AR's get very stable, like a bullpup. It's a totally different feel compared to a lightweight bolt action hunting rifle.

I'd recommend:
14.5-16" barrel, as thin and light as possible. 16" Larue Predator 5.56, 14.5" Predator .300blk, 14.5" Larue Stealth, 14.5" BCM ELW for examples. The Faxon pencil barrel you mentioned looks great. I haven't shot one yet to know if it's reasonably accurate. Lightweight barrels rule, especially the ones that are tapered.

Mid gas
Carbine or A5 buffer tube.
Larue stock, with a standard cheap A3 carbine stock available to try less weight.
Stag Ambi safety
BCM large charging handle
Larue Grip
Eotech XPS
Larue Eotech QR mount/riser

The thinnest 13" keymod or m-lok hand guard you can find. My carbine is the Larue Ultimate upper kit, my 3gun carbine uses a thicker ALG EMR GenII m-lok rail that is an excellent budget rail.

Larue Tranqillo mussel brake, or a Battle comp 1.5 if you want a little less blast. Pinned and welded of course. Precision Armament makes the best mussel brake, the m4-72, but it may be a bit annoying for a long class. The M11 is a great comp, not annoying at all, but a little bigger.

The kit I used for my new defensive carbine:
http://www.larue.com/larue-ultimate-ar-15-upper-kit

I want to build another in 5.56, but a few cases of .300blk ain't going to kill me either. I might just use .300blk for my next carbine class. No reason I can't shoot my 5.56 3gun rifle for a bit as well to save ammo cost.

I bring about 20 magazines to training. 30, 20, 40, and 1 set of clamped 20, 30, and 40 round mags. All Pmags.

My 3gun rifle uses a BCM SS410 18" rifle gas barrel. It's heavy. But usually, long range shots in 3gun require a table, barricade, or barrel. So heavy is good. Very good if you want to see your hit in the scope. None of that is good for a CQB carbine class with 1x scopes. You want lightweight for that.

So it depends on the rifles use. Lightweight is great with 1x scopes. Always go as light as possible with iron sight carbines and reddot carbines. But if we're using 1-8x scopes and supported long range shots, more weight is nice.

 

[briansmithwins]

556 is a very soft shooting round out of an AR. Personally I'd go with the lightest barrel for a short handy carbine. I also wouldn't bother with a free float tube if it adds weight over a stock handguard. Midlength gas is also preferable for 16" barrels, in my opinion.

For long range shooting I'd go with almost the exact opposite.

BSW

 

[Jackal]

I dont think so. My 11.5" carbine is very light and it swings great.

 

[MachIVshooter]

A carbine that is very light in the front will be more difficult to steady for precision at range, but will also be better handling for the uses you intend.

Think inertia (resistance to movement) and momentum (resistance to cessation of movement). More mass will have more of both. Lighter weight means the same amount of force will accelerate and decelerate the object in less time.

 

[MistWolf]

The Faxon GUNNER profile is better than a pencil profile. It's tapered so there is more mass at the chamber end for better heat management, and tapers to a thinner profile at the muzzle for lighter weight while keeping the center of gravity closer to the rear. It's the same as a sporter barrel profile found on good hunting rifles.

That's not to say a pencil profile bare is a bad choice. The Faxon pencil profile barrel is a little bit lighter than the GUNNER

 

[Doc7]

Thanks all!!!! This answers all my questions.

I am very excited to have a second upper to go with my SPR build and have an AR15 ready for any of my conceivable purposes!