Tuesday evening coaching a probationary member who's using a club Anschutz 1907 standard rifle. Basic process OK but position was a little slack and tending to move the butt around in their shoulder during the detail.
So, tightened the sling one notch and a discussion about letting the sling take the weight, and maintaining the shoulder pressure particularly during operation of the bolt to help keep the butt-plate in the same location as moving the butt-plate fractionally will move the NPA.
I have to say, the results are not normally this impressive. The first two diagrams are groups of 5 each. Then the changes/discussion. The third diagram is a group of 6!

Crack on and keep up the good work!