I have seen them do it it and their is no bulge in the barrel they have done this hundreds of times. I personal have never done it or recommend it but seen it and their is no problem. I have shot their gun at turkey shoots with low brass 2 3/4" shells so I have looked at the barrel no problems. The reason they have to pump hard or cut the shell out is the empty shell is larger then the receiver opening. Again I DoD not recommended it but I have seen it done and their is no problem with the barrel. The barrel is a 3" chamber again, they don't shoot 3" in 2 3/4" chamber barrel.