6 arc…. 12” vs 16”

[Nomad88]

Help me decide.

I had a 12” briefly a year or so ago and was able to get 105’s at 2500 fps. Looking to run 85’s in this and think the 12” would give very good velocity for its size.
Also will be very handy suppressed.
I’d buy a 12” barrel for my sbr lower.

Or should I go 16” route. Not quiet as handy with a can but more velocity.

 

[David Milisock]

Help me decide.

I had a 12” briefly a year or so ago and was able to get 105’s at 2500 fps. Looking to run 85’s in this and think the 12” would give very good velocity for its size.
Also will be very handy suppressed.
I’d buy a 12” barrel for my sbr lower.

Or should I go 16” route. Not quiet as handy with a can but more velocity.

I'm assuming that you're talking a boltvrifle, correct?

 

[10XSHOOTER]

He said it would go on his SBR Lower. Reading this as a gas gun

 

[David Milisock]

He said it would go on his SBR Lower. Reading this as a gas gun

I'd bet that he's not getting those 105 grain velocities in a 12" barrel at 52,000 PSI! I get a bit more than that in my 16".

 

[Nomad88]

I'd bet that he's not getting those 105 grain velocities in a 12" barrel at 52,000 PSI! I get a bit more than that in my 16".

Are you using factory ammo? I bet if you loaded 105’s with lever powder, you’d get those velocities.

 

[David Milisock]

Are you using factory ammo? I bet if you loaded 105’s with lever powder, you’d get those velocities.

Not with safe pressures, the AR 15 bolt has exhibited lug failures, the larger cartirdge head and bolt face increases bolt thrust. There have been a multitude of documented catastrophic failures.

That's why Hornady shows two sets of data, one for the AR and another for bolt rifles.

 

[gunsandgunsmithing]

So which is faster, velocity wise...a fast or slow twist? I've never seen enough difference to say either way, myself.