Follow-Through
Maintaining the same shooting position and sight picture through the trigger break and after the bullet has left the barrel.
The bullet is in the barrel for about 1.5 milliseconds. Any movement during that window pushes impact off the call. Follow-through means staying in the same position (same cheek weld, same trigger contact, same grip) until the rifle has fully cycled.
One telltale sign of weak follow-through is a group that strings consistently in a particular direction. In that case the shooter is unloading the rifle just before the bullet leaves, and doing it repeatably.