Actually
Centerfire groups are measured using a device that returns center to center measurement. No subtracting occurs. The reason for the device is the inconsistent size of a single bullet hole.
nobody measures center to center in group benchrest matches, maybe in your back yard, but not at the supershoot, or any other offical match. and wether you shoot at 10 feet from the target of 1000 yards its still the same. outside to outside less the bullet"""""""""
Centerfire groups are measured using a device that returns center to center measurement. No subtracting occurs. The reason for the device is the inconsistent size of a single bullet hole.