barrel length for suppressor

[trickyric]

I am not sure if this is the correct forum but I'll ask anyway.
I have decided to upgrade the barrel on my Remington 700 build to a Bartlein .30 1:10 M24 r5.
My original AAC-SD barrel was 20 inches and I only shoot it suppressed. Since I am doing this new barrel I can have it all the way up to 26 inches.
Any recommendations for proper length for best accuracy?

 

[CanPopper]

I've found that shorter actually gives me better accuracy. And I get way less POI shift too. My 17" DTA .308 has about 0.5" of POI shift while my 26" Win Mag has 3" on the same titanium suppressor.

For my AR, my 24" AR has a more unpredictable 3" down while my 16" AR has a very repeatable 1.8" up.

In both cases, the groups for my custom loads are tight so not much of a difference there. You could need to do a load test with a suppressor on due to changing harmonics but the shorter barrels definitely gives you less POI shift.

 

[Outlaw1]

Good stuff to know!

 

[nfoley]

I have found the same with POI change - shorter barrel has less POI change.
I have not found any difference with accuracy though - have used mine on 26" 6.5 CM with no change in accuracy.
I really like shooting my 16.5" 308 suppressed - just feels easier to move around with.

 

[trickyric]

I think I am going to keep it 20 inches.
I use this rifle for 1000 yards.
We also decided to true the action and order a custom PTG bolt.
I am also changing the rings and mount to a Nightforce directmount.
I am trying to eliminate any possible cause of shift in zero.

 

[Delta4-3]

18" is as long as I ever build a .308, but I like 16" better.

 

[trickyric]

We are talking about a bolt gun?

 

[RELOOP]

I make good hits @ 800 with 18.5" barrel / Surefire FASS, groups tightened up with the can.

 

[mpw20]

nfoley-- is this the same supressor run on both the 26 inch 6.5 CM and the 16.5 inch 308?

 

[Enough Said]

Shift in zero from what reference? Non-suppressed? Expect that, but you won't experience it if you always shoot suppressed or not.

 

[trickyric]

the zero was moving a half mil from a rifle with a suppressor on it. After 4-5 shots the zero would move exactly the same amount.