Be advised that if you are zeroed for 25 yds., using iron sights, and are attempting to shoot groups at 100 yds with a standard velocity .22LR round, your POI in relation to your POA will be about 9 inches low at 100 yds. Use a large target so as to not end up with complete misses. A 2 ft. x 2 ft. target with a 5 inch dot in the center will work for this purpose.