It does
The bullet has decelerated to subsonic speeds (900feet/s) by the end of its journey.
As far as "anybody shooting back" the only commonly used weapon around those parts capable of shooting back at that distance is the ZPU. If they did not have it, the sniper could (and probably did) take shot after a shot after a shot without them being able to shoot back. Until he (or she - women are actually even better than men at this) hit them.
Biting the hand that feeds IT
