I own a Remington model 760 GameMaster chambered in .270 and I am having a problem. When i make a shot, and quickly slide the pump back, eject the shell, and am ready to feed the next one in, that bullet im feeding in jams up.iv tried everything , making sure i completely eject the shell, slide the pump all the way back, put her forward relatively quickly, i dont what to think. has anyone else had this problem, and if so, is there anything i can do to fix it ??? thanks.