Subsonic .308

[xryan.jacksonx]

I'm on the verge of picking up a .308 rifle for use with a suppressor. Looking at the subsonic offerings on ammo, most list 1 in 10" twist rate and a few say 1 in 12" are required for bullet stabilization. Is this the minimum or is it required to be exact? For example, would ammo rated at 1 in 12" stabilize out of a 1 in 10" barrel?

 

[wsenefeld]

For subsonic .308, you will have a long, heavy, and slow moving bullet. Therefore, you will need a faster twist to stabilize it and avoid having a baffle strike. The 1:10 twist will still stabilize anything else you want to shoot out if it but it may not be as accurate with the lighter bullets. I have an 18" Mega barrel with a 1:10 twist and it stabilizes 147gr M80 bullets just fine. The 147gr bullets aren't that accurate but they do stabilize.

The 1:10 will avoid potential damage to your suppressor with subsonic ammo. To achieve moa accuracy with supersonic loads you will most likely need 168gr or heavier.

 

[DarrenL]

I agree, gotta be careful to avoid baffle strikes.

 

[r6vr6]

I have a rem 700 aac (1:10) I have used 208 gr hornady match projos with trailboss powder. Accuracy was okay but it was whisper quiet. It loves 168 gr match projos for supersonic loads. Some of its favorite ammo is HSM 168 gr or atomic 168 gr.

 

[M67]

I've had some fun with about 8 grains of red dot and a 180gr bullet. They stabilized in my 1:10 twist and I just loaded them to play with them and ring steel at night

 

[sgreen3]

Ive been researching this same question for a while now and it seems like a lot of guys favor the 208gr Amax over TrailBoss powder. Not real sure on the OAL their using but from what Ive read it very hush hush....

 

[ryknoll3]

Ive been researching this same question for a while now and it seems like a lot of guys favor the 208gr Amax over TrailBoss powder. Not real sure on the OAL their using but from what Ive read it very hush hush....

2.800" OAL is pretty much good to go in .308. That's what my Hornady load book lists as OAL for the 208 AMax's.

 

[Slow Hand]

I have shot some .308 suns through my FNH PBR. I believe it has a 1:12" twist barrel on it. I think I was shooting Sierra Game Kings, 200 gr. It was very quiet but obviously hit way below standard velocity POA. The best way to be sure is to put a target up pretty close, like 10 feet from your muzzle and shoot some rounds through it before screwing your can on the rifle. Some bullets will 'settle in' at further distances and will look like they are shooting straight but can still give you baffle strikes.

[video]https://youtu.be/zOOLnMRDM6c[/video]

 

[sgreen3]

2.800" OAL is pretty much good to go in .308. That's what my Hornady load book lists as OAL for the 208 AMax's.

Yea my Lee manual lists them at the same OAL. Good to know though, I just didn't know if there was any difference with running them subsonic or not.