My sons sbe which i owned for i think 7 years , which i gave him, will not fire while shooting trap at least one or two times a round. All the years that i have owned this gun i never had this problem. The gun is clean and properly oiled and i know he is not doing anything wrong while loading it each shot. For some reason i do not think the bolt is fully engaugeing to the fire position. Every time this has happened i checked the shell and no dent on primer either. Any ideas would be appreciated.