Atomic Ammunition 00482: Atomic Ammunitions 6.5 Creedmoor Subsonic ammunition is unlike any high powered rifle ammunition. It is quieter than most .22 Long Rifle ammo, has virtually no felt recoil, produces the same energy and power as many .40 S&W police service rounds and delivers excellent accuracy past 100 yards from rifles with barrel twist rates of 1 in 11 or faster.