I recently purchased one of their stocks. It installed just fine and fits well. Problem is when I clamp everything down it causes cycling issues. The gun ran fine before and runs fine when I put it back into the original configuration. I suspect is has something to do with the rear clam shell but I cannot figure out the problem. I have fitted brand new magazines in hopes that would resolve the issue but it does not. Without the Kushnapup stock installed it will function fine with low brass Federal. With the stock it is 50/50 with high brass ammo and I might get two rounds to fire consecutivel