energy. since the subsonic .22lr, fired from a rifle, still has that much energy left at 100m, and since 90+ % of the NONACCIDENTAL hits in combat occur at 100m or less, why would anyone "think" a silenced 10-22 Ruger AINT lethal, ferchrissakes? Even with "mere" leg hits, the cutting of a major blood vessel is still pretty likely, along with shatter of femur, nerve damage, etc. Aiming at hip or upper thigh, in ACTION, will OFTEN mean a gut or pelvis or privates hit, with high likelihood of death, if not in a GOOD hospital within a VERY few minutes.