. 22 Subsonic rounds are sometimes fitted with extra-heavy bullets (46-61 grain) to facilitate better terminal ballistics of the smaller and slower projectile. A common example of a subsonic round is the Aquila .22 LR SSS “Sniper SubSonic” while a popular hyper-velocity round is the CCI Velocitor. The former is a 60 grain round while the latter is a 40 grain.