Possible Ithaca 37 problem

[Armadillo]

Ive got a newer style Ithaca 37 pump 12 guage and when I fire it the shells get hung up inside the barrel and wont eject after being fired. This occurs roughly every 5th shot The gun has not been used very much so I was wondering if it just needs to be shot for a while or if there could be a possible problem here. Ive also fired several different brands of shells in it and the problem is still there