When I was shooting NM/Bullseye many years ago, it worked for me that I would use center-mass for 50 yd, and 6 o'clock for 25 yd. I didn't have to change my sight dope. I used the same technique for .22, CF, and .45, and it was not unusual to end up with 99-9X, or possibles on both strings. Like most shooting techniques, "if it's stupid, but works, it isn't stupid."