Well it's awhile since anything has been added, I've been distracted with other things but there is some progress. As a matter of fact, I'm about ready to do some preliminary tests. Here are some pics of the nearly completed test tube, so to speak. I'd like to add more but I can see there is a limitation. All I have to do is cut a slot in the backstop for the triggering mechanism. As I've stated before I'm paranoid about closing the bolt on a hand grenade so I'm working on a pneumatic actuator that does away with all of the cocking mechanism other than the firing pin, bolt shroud and cocking piece. Unless there is another stray asteroid in the wings, it will be fool proof. Realizing, full well, there is no such thing. The first rounds are going to be tame just to test the system and this I'll do with the regulation parts, and, a Kevlar glove.