A friend was shooting his Armalite this weekend at targets set up at 850 yards. There were several shooters trying their skill at long range shots. The first shooter did quite well hitting the target three times in his first attempt. The next two shooters were impacting the ground about 24" above the target on their attempts. The first shooter shot again and hit the target twice with both tries. My friend asks why did/could the point of impact change with no adjustments in the scope, loads, or conditions, only the shooters. Could it be just the way each indivual sees thru the scope? The scope is a Leupold 6.5x20-50mm in a 30mm tube. It is mounted securely with no loose ring or base screws and no apparent failure in the scope.
Of course more shooting is planned but in the meantime he is looking for any advise and or comments from others.
Thanks, Chief

I would think the difference in point of impact has more to do with how the different shooters are holding the rifle and the difference in the movement of the gun in recoil.

The harder, ie more a gun moves, in recoil, the bigger difference you will see in differing points of impacts with different shooters.

The POI can also vary with a single shooter if he shoots the gun from different positions.

For instance with me shooting a 308 heavy barreled rifle I shoot one inch lower at 100 yards when using a sling prone vs using a Harris Bipod. I shoot with a fairly taunt sling.

Shooting off a bench at 500 Meters I hit 2 minutes lower, than I do standing...

That is @11 inches at 500 meters.

It is not uncommon for several people using the same 50 cal. to have different zeros.

Sometimes windage can be effected as well.