The TulAmmo KVB-7.62 primer is NATO spec and less expensive than most and creates the lowest velocity SD's I've seen. The only real technological downside is They are really a slightly limited in shape, so you wish to be extra watchful for getting them underneath flush with the case head. https://zndhtchencci30091345.59bloggers.com/31966783/cci-550-no-further-a-mystery