I have a new XCR in 5.56, I got the Bill Springfield trigger job done to it (stock trigger pull felt really bad) and am having some problems with it. I first had the bolt that was cutting nice little holes out of the primer due to an improper chamfer. Got a new bolt in the gun and since then I have had many failure to fires due to light hammer strikes. Now I honestly don't remember if I had any of these before I got the new bolt or not since I only fired 10 or 15 rounds and the gun locked up so tight I could barley get the action open, then I saw holes in the primers of the brass. I contacted Bill about this and he said the only thing his trigger job may have done to contribute to this is the hammer spring is bent at about a 45 degree angle to lighten the trigger pull slightly, so I put the hammer spring back the way it was. Robinson said to finish the break in period and see if the problem goes away. Well I am now past the break in period and I am still getting lots of round that are not firing. When I take some of these rounds and run them back through the gun they sometimes go off, not always though. And my Kel tec loves this ammo, it eats just about anything, so I think the ammo is good. The ammo that does this the most is 5.56 Guat surplus, but this also happens with radway green and HSM. The strikes look kinda light across the board, but not always consistent. Anyway has anyone else run into this problem? After waiting so long for this rifle I am really trying hard to find a reason to keep it, but it just doesn't seem to work well for me.