And in shorter barrel lengths (~8″) the 300BLK is way remarkable for supersonics, at least. Long barrel 300BLK is close to pointless IMO, you could find other rounds that outperform it handily in the exact same System, with similar size barrels. There are numerous three hundred Blackout masses that meet https://300-blackout-cases58754.luwebs.com/39839127/getting-my-300-blackout-brass-to-work