I have an issue that some times I fire a shell in my gold 10 and it ejects the shell fine, but the next one is not picked up and loaded. The bolt closes and there is no shell. The other two shells dont move from the magazine at all, they are not getting jammed any where. I manually pull the bolt back and the next shell pops up no problem. This happens about 1 out of every 15-20 shells I shoot. Any ideas?