Best Bullet Weight 300 BLK Supersonic 8.5" 1:7

Barnes 110gr TAC-TX do pretty good.

Take a look at lil gun for the 300 blk. It’s my favorite powder for it and I have h110 on my bench. I use lil gun exclusively in 300 blk supers and in 450 bushmaster. I despise the name of the powder but love the performance.

I've got no .300BLK specific recommendations, but keep in mind that what stabilizes a particular bullet at a certain twist rate is more about it's length than it's weight.

Which means that, for example, an all copper bullet ( like those from Barnes) that stabilizes well in a particular rifling rate will be significantly lighter than an equally well performing copper jacketed lead projectile.

But a 1:7 twist is fast enough to stabilize even 220gr all cooper bullets even at subsonic velocities. 1:7 is fast enough to stabilize any supersonic bullet you might shoot out of 300 Blackout.

I've had good accuracy with 125grn Sierra prohunters in 8.5 and 16" using g h110. However, you do not get enough velocity out of the short barrel to get expansion with them, so they are not a good hunting bullet. But they cost about half what the Barnes bullet does.....

Also, it cracks me up that Sierra lists different load data for h110 and w296, given that they are the same thing.