Just occasionally give the cartridige time to "rest". That's one reason you'll hear complaints about a 1077 not getting many shots, it's a repeater. I try to take a couple of guns to target with so that when I've squeezed off a couple of mags. from the 1077 I shoot something else for a while (I've got 3 1077s plus several other air guns.). The cartridige chills as you shoot, pressire drop=tempture drop and vice versa. Let the cartridige rest and it will give you a few more shots.