I hate to disappoint you but generalizing that all rifles shoot high after cleaning is totally wrong.Some rifles will shoot high ,some low some right, some left and some will not change point of impact whether fouled or clean.I hunt with clean barrels as testing has shown that my rifles do not change their point of impact or group size after I have cleaned and dry swabbed them.Your cleaning methods as well as the individual firearm will determine what effect cleaning has on your particular gun.