Ar pistol barrel length

[fadetoblack188]

Ok I’ve been trying to do a lot of recent and can’t decide between 10.5 and 11.5 inch barrel. What’s the word around here.

Looks like the the 10.5 obviously is a inch more compact which is nice but might run into some hiccups. The 11.5 is an inch more cumbersome but velocity wins. Obvious this will be a 100 yard max.

Thoughts ?

 

[Eli17L]

Non expert.
10.5 ok and more choices.
11.5 better fewer choices.
I like velocity no matter the range.

 

[alamo5000]

It depends on the use. My 10.5 is my most shot firearm. It's extremely reliable as well. I love it. Velocity will be dictated by ammo choices. That sounds like a obvious statement but I have been doing testing lately and I got over 180 fps more out of my loads using specific powders than factory ammo of the exact same grain weight. I am sure I can get even more velocity once I get some more other OOS powders to test.

For terminal ballistics 62gr soft points and up to 77 grain projectiles tend to do better.

 

[UpSideDown]

12.5 > 11.5 > 10.5

An inch of compactness doesn’t necessarily make that much of a difference in handling.

I love my 11.5 BCM. There is a significant velocity difference between 10.5 and 11.5, and a healthy change going to 12.5. Since they typically all run the same length gas system, the longer the barrel the smaller the port can be, giving you a softer shooting and reliable gun. Any of them can be made rock solid reliable. If you go 10.5 I’d probably grab a Daniel Defense or LMT barrel since there’s a lot of them. LMT might also make an 11.5.

 

[Steve_In_29]

10.5" is a lot harder on the gun as cycling is more violent.

11.5" is a bit easier on the gun and gives a bit better terminal ballistics (what I went with)

12.5" if I had to do it over

 

[TonyTheTiger]

I've got a 10.5" CLGS and a 12.5" MLGS. Everytime I shoot them I remember why I'll never buy a carbine gas barrel again. The 2" length gain is negligible, especially considering the increased velocity, range and shootability.

 

[fadetoblack188]

Looks like 11.5 is the sweet spot

 

[shoobe01]

10.5" for pistol calibers of any sort, and .300.

12.5" for 5.56.

 

[Steve_In_29]

10.5" for pistol calibers of any sort, and .300.

12.5" for 5.56.

And iirc you can get a mid-length gas system in a 12.5".

 

[ut755ln]

Ok I’ve been trying to do a lot of recent and can’t decide between 10.5 and 11.5 inch barrel. What’s the word around here.

Looks like the the 10.5 obviously is a inch more compact which is nice but might run into some hiccups. The 11.5 is an inch more cumbersome but velocity wins. Obvious this will be a 100 yard max.

Thoughts ?

10.5

 

[McCrazy]

For an AR pistol like the OP said you are fine with a 10.5" setup for .223/5.56mm.

If we were talking about SBRs though I would recommend the 12.5".

We ran 10.3" Daniel Defense uppers in my old unit. The velocity loss was substantial. Muzzle flash unless you used a suppressor was a major detractor but adding a suppressor also added length and weight back onto your weapon. Without a suppressor the pressure of the muzzle blast from you and others firing within rooms and enclosed spaces is also less than ideal. Bolt speed was also very high and gave the sensation of more noticeable recoil.

All of these negative effects get reduced substantially with a 12.5" or slightly longer barrel, especially if you go to a mid-length gas system.

If you get too close to 14.5" though you might as well do a pinned muzzle device and skip the SBR though.

 

[Nik H]

I have an LWRC piston driven version with a 10.5" barrel that's chambered in 6.8 mm SPC.

It is a riot to shoot and deadly accurate with a red dot