At the velocity of a 300BLK SBR I would guess that they would be adaquate. A head/neck CNS shot should work fine.
If the deal is to shoot one controlled shot,then spray and pray as they scatter,I would suggest a bullet with more penetration and momentum.
The Barnes 120,110,or the 130gr "pulls" should work fine. The 125gr Nosler BalTip Hunter should be another. All these are fairly expensive though. Scan the interweb for "pulls". A buddy and I went together and bought some that came from the Remington Hog Hunter line of ammo. It is a solid copper 130gr bullet that is similar to the Barnes TSX but with a more gradual taper. ---- pruhdlr