I probably worry about details like this too much, but here goes: You load 11 rounds into each of four magazines. You put one in the gun for your first string, chamber a round and when the buzzer sounds, you are off to the races. You are shooting exceptionally well today and with six rounds you hit all six plates. You now have one round chambered and 4 in the magazine. You change out the magazine for one that has 11 rounds in it. You now have 12 rounds in the gun, the maximum number of rounds allowed is 11 for Glock the Plates. Should you have taken one round out of the fresh magazine leaving you with 10 in magazine and 1 chambered, cleared the gun and then started over using the fresh magazine with 11 rounds or is this something that one doesn't need to worry about? Thanks wilhelm Wanna kill these ads? We can help!