As well as in shorter barrel lengths (~8″) the 300BLK is much outstanding for supersonics, no less than. Very long barrel 300BLK is around pointless IMO, you could find other rounds that outperform it handily in exactly the same platform, with similar size barrels. Castings are robotically or manually ground https://tysonncqak.fireblogz.com/70361599/5-easy-facts-about-brass-300-blackout-described