building sub sonic 308 questions..

[AusFclass]

Looking at putting together a sub sonic 308.

What twist rate and barrel length are you running and with what bullets have you found works well.

I'm thinking 155-210gr bullet range any advice on loads and barrels would be greatly appreciated . . . . . . And please don't say "get a 300 BO" haha

 

[boltgunluvr]

150gr SPT flat base Sierra with IMR TrailBoss. 1 in 12 twist.

 

[half]

I tried a bunch of different bullets in my 12 twist barrel, and I couldn't get any of them to shoot consistently. I was trying to find an accurate sub load to do suppressor demos. I also helped a buddy develop a load for his 10 twist, it was a lot easier. I think he settled on 180's and about 9 grs of trailboss. I can get the exact load if you want it. Elevation here is about 3100 feet.

 

[1shot]

10.8 of Trail Boss/180 SMK, 200 SRN, 208 Amax. Great accuracy out of my 16" bolt rifle with a 1-8" twist. Using a Gemtech Sandstorm it makes less noise than un-coupling an air tool from the hose. The 1st time I fired it, I would have bet the farm the bullet was stuck in the bbl. except for the clang of the steel 100 yds out!
I hope this helps,
Lloyd

 

[AusFclass]

So probably a 1-8 or 1-7 would be the go?

And trail boss is the go to powder?

We aren't allowed to have suppressors over here at the moment but there may be provisions in the new act being updated soon.

What makes a good suppressor vs a average one?

even if they don't get approved it would still be a good project.

 

[d.id]

I use a 16" 8 twist, got best results with 12 grains of trail boss pushing 225 hornady bthp.