khan shotgun problem
 

its brand new and shot about 30 times. itwont eject the shells now, the first 15 it worked fine then i cleaned it and they all worked except one. then i went hunting again and not a single one will eject. so i brought it home and took it all apart and cleaned and oiled everything and still the same thing. im thinking that it might be not enough recoil to bring the bolt back all the way. its semi-auto and 3'' chamber and im shooting 2 3/4'' shells because i cant find 3'' anywhere around here unless its steel shot or heavy phesant loads which wont work and where we got the gun they said to use 2 3/4'' and they were working fine. can someone tell me why it might be doing that, im gonna try some shells with more powder tommorow.