Alright it looks like it might actually indeed have a built-in nub... what do you guys think?
So given that, any ideas on how to get it to extend into the chamber? Just fiddle with the gears and orientations until I can get something to happen? I assume even at fully extended it should only just show up when looking down the barrel, given the millimeter tolerances we're talking about here, correct?
Thanks for the help so far guys.