AR15 Question,Bullet weight vs Barrel twist

[375rum]

Application is a 16 inch barrel,heavier profile,chrome bore
1 x 9 barrel twist.What is the heaviest bullet weight I can
use with any accuracy?Thanks 375rum

 

[Airborn_69]

Not too sure on the heaviest but I'd say 69gr BTHP's would work well.

 

[375rum]

Thanks Airborn,ran a search this morning on my work comp
(klunker at home is old and dialup) and see this has been
hashed out plenty before.The consensus seems to be up
to 69 grn bullets.Thanks 375rum

 

[Paulinski]

You can try 75gr and 77 gr to see if your barrel will stabilize them.

Some barrels are 1 x 8.8 and some are 1 x 9.2 for example bottom line is you won't know until you try.

 

[KevinB]

Stainless barrels with tighter chambers seem to do better as a rule of thumb. Higher velocities help (which is why the above). The issue is the length of the projectile not specifically the weight.

M856/C78 Tracer is 60gr but 1:9 will not stabilize them due to the length of the round.