I had some trouble getting the extension tube on. Chopped off the crimped end of the tube (the first time) without any problems but the threads were still a mite to long. Sooo back to the cutting. Was going pretty good until my hand slipped and the end I was working on got dinged. Put it back together and the follower would jam on this spot. Took it back apart, FINALLY got it all made pretty round again and now it feeds like it should. Now to get a box of cheap (yeah I know) shells to do a real function/reliability check.