I have an XT. Last week it started hitting light on the bottom barrel. At first I thought maybe I ran into a bad batch of primers. As it started being more frequent, I put the shell in the top barrel and it went off. So I shot my top barrel from there forward with all shells firing off first and then all shells went off in the bottom barrel there after. Any thoughts on what might be going on? Bottom barrel firing pin? Hammer Spring? Any help would be welcomed. Havent shot it thst much considering I got it new. I wouldnt think there's 3000 rounds through it.