The TulAmmo KVB-7.sixty two primer is NATO spec and less expensive than most and produces the lowest velocity SD's I have observed. The only technological disadvantage is they are a slightly limited suit, so you need to be added very careful to obtain them under flush with the case head. https://zndhtchenccibr241772.bloguerosa.com/30717797/detailed-notes-on-cci-zündhütchen-large-rifle-200