And in shorter barrel lengths (~eight″) the 300BLK is far top-quality for supersonics, at the least. Very long barrel 300BLK is around pointless IMO, you'll find other rounds that outperform it handily in exactly the same System, with exact same size barrels. You'll have to tweak subsonic handloads depending on https://brass-300-blackout27278.aioblogs.com/91163719/300-blackout-reloading-can-be-fun-for-anyone