AR15 Barrel length

Coyotejunki

Coyotejunki

Well-known member
How may of you guys are using 16" barrels to hunt with. I was always a 20" barrel guy until I got a suppressor. Now I am running an 18".

With a 16" barrel does the AR give up much compared to an 18 or 20? How about accuracy, do the shorter stiffer barrels generally shoot better?
 
That 18 inch barrel with rifle length gas tube is about as good a set up as you can ask for running suppressed.

The next best thing down from that would likely be a 16 inch barrel with a mid length gas design.

Shooting Federal 5.56 ball ammo will get you a touch over 3,000fps in standard conditions with a standard 5.56 chamber and a 1/7 twist. I have chrono'ed a bunch of those back in the day.

I am stepping down to a 16 inch 1/9 hunting rifle too. My suppressor is thought to be approved any day now. I went with a carbine length gas system, adjustable block and a David Tubbs buffer spring.

I am hoping a fast powder and the parts combo will band-aid the poor decision to go carbine length?

If i could have found a quality 18 barrel with rifle gas system and a 1/9 twist i would have bought that.

Oh well.... Starting with H335 & AA2200

I am hoping to be on the accuracy node, at safe pressures and at darn close to 3000fps. If not i will try a different powder.

I had been dropping Coyotes on the spot with my worn out MK12, 18 inch barrel with 55 grainers flying just under 2900fps. (accurate but slow load)

I only use 55 grain bullets for Coyotes.

What bullet weights are you shooting?
 
A 20" really starts to feel long with a can on the end. They are just not very handy. We have never had much trouble dropping coyotes with 16" barrels at typical calling ranges using 55gr and 60gr Vmax.

I just received my SBR stamp and am thinking about building a 12" 6.5 Grendel, which with a silencer will end up about the length of an unsuppressed 16" AR. Even a 12" 6.5G has more muzzle and downrange energy than a 20" .223, which is something to think about if you are concerned about the energy of shorter barrels.
 
On a 5.56/223 AR, its my understanding that you lose ~50 fps per inch of barrel removed. Obviously that's a very rough estimate - not an exact number.

Anyway, I recently decided to challenge my own assumptions about barrel length/profile, so I built a 16" upper with a light profile barrel. I just started working on load development for it, and it may be my go-to coyote rifle if all goes well.
 
I hope this suppressor tames the bark of the 16 inch barrel. My 18,20 & 24 inch barrels are much more pleasant to shoot.
 
You aren't giving up much of anything. The 50 FPS per inch is a ballpark figure. You really need to put your rounds across a chronograph to know what they actually do.

I have shot the 123gr Hornady Black, ELD match out of my 16in 6.5 Grendel. Hornady lists the velocity of the ammunition at 2580 out of a 24in test barrel. I chronographed the ammunition from my 16in at 2411 FPS that means that I lost 169 FPS from an 8in drop in barrel length which comes out to be 21 FPS per inch.

Will you lose accuracy? Maybe not. Not if the barrel can still stabilize the bullet. Again, 16in barrel, and we were able to do this, at 400 yards:

19756732_1814915648747914_8381668159719500221_n by Jason Mosler, on Flickr

Yes, you are going to give up some velocity. But the reality is that you can compensate for that. We have shot our 16in guns to over 1,000 yards. It can be done.
 
[
I only use 55 grain bullets for Coyotes.

What bullet weights are you shooting?/quote]

I generally use Sierra 55 SBT's. Though a friend says the Sierra 69gr TMK works great, and it is shooting tighter groups than the 55 so I thought I would try it, or my old standby the 60 VMAX.
Click to expand...
 
Originally Posted By: steve garrettAbout 200 FPS is what you give up. That is something considering the 223 is under powered already.

Thanks for the chuckle... I've piled up plenty of deer and hogs with the .223 Remington cartridge.

I've taken some really big nasty boars with a 77gr. OTM load.









Yes, the .223 can be said to have limitations when compared to other cartridges, especially at distance. I consider the .223 (with the right bullet) when used within reasonable hunting distances (300 yards) to be quite capable of taking game.

All those above kills were with a 16" barrel using either 69gr or 77gr SMK loads.
 
My polygonal rifled 16" is shooting its favorite 65gr SGK load a good bit faster than my 24" land and groove shoots it's favorite 69gr SMK load.

From now on polygonal barrels will probably be the last I buy, great velocity and accuracy.
 
I have AR’s from 7” out to 29”. My go-to Coyote AR most recently is a 10.5”. The 10.5” isn’t a 700yrd rifle, but it gets the job done at calling distances, and with a SiCo Omega our front, it’s no longer than my old Go-To rifles which were 18-20”.
 
Regarding barrel length and velocity, I chronoed a handful of loads through an 11.5" and a 20" and the 20" was consistently about 400fps faster, for whatever that's worth.
 


This is my AR pistol soon to be a SBR 10.5 300 BO with a Specwar 7,62. Got the forearm from Midwest Industries

jzqXBRC.jpg
 
My AR-15 varminter has a 24" barrel on it and a suppressor. Sure, that's a lot of tube but I only shoot small furry critters off the bench with it so I will take all the barrel I can get.

I had a 16" AR with a muzzle break on it and it was so horrible to shoot compared to my longer barreled one that I traded it off. I dont miss it at all.
 
Rustydust,
You could have gotten a linear muzzle brake on that 16" AR and at least directed the blast forward. That's what I have on my 16" barreled calling rifle and it is a more "polite" rifle for my calling buddies.
 
Originally Posted By: HellgateRustydust,
You could have gotten a linear muzzle brake on that 16" AR and at least directed the blast forward.

That gun actually had a 14" barrel on it with 2" of it being a welded on muzzle brake to make it of legal length so there really was no easy way to change the brake on it. It was light and carried well but was dang unpleasant to shoot so it got traded. One of my shooting buddies has a 10" T/C pistol in .223 that is less punishing on the ear pans than that thing was.
 
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