As well as in shorter barrel lengths (~eight″) the 300BLK is much excellent for supersonics, at least. Lengthy barrel 300BLK is in close proximity to pointless IMO, you could find other rounds that outperform it handily in a similar platform, with similar length barrels. Castings are robotically or manually ground https://simonloqtp.blogdosaga.com/37677390/getting-my-300-blackout-cases-to-work