How many groups did you shoot at 100 yards.
If your shooting good groups at 50 yards 1" that would be 2" groups at 100 yards.
If you are right on the zero at 50 yards your impact will be 1 1/2 inch higher at 100 yards.
Shoot 4 or 5 groups (let your rifle cool between groups) at 100 yards with a good solid rest (not off your coat over the hood of the pickup).
50 yard groups are ok to get you on target at 100 yards, but they aren' t much use for testing out your rifles accuracy.

If your rifle is shooting 1/2 inch groups of 3 shots at 50 yards it should be shooting 1" groups at 100. If you are shooting groups that good at 50 but much worse at 100 (at your scopes highest magnification) it is not the fault of your equipment, you need to work on your technique or your rest.
Good luck!