I thought i was the only one with an HFC M190! Mine's full auto with an extension (about 2" of barrel extra) Sorry i can't help with your questions, but i do have some of my own!
My selector switch has stopped staying on the selected mode (FA-SA/-S). It freely moves from one side to the other. I took it apart and couldn't put the pieces of the floating valve (#30) back together. It has a little tiny spring and a plastic piece to hold it in... i'm finding it impossible to put both back into place. But even with the floating valve in place where it was, i wasn't able to figure out what keeps the selector in any one position. I've fixed it temporarily by jamming a piece of black zip tie around the curvature of the selector, but i would like to be able to switch to full auto, and SAFE! Any ideas?
I'd like to take the extension off, i find it unnecessarily long. When i attempt this i find the inner barrel (#74) (i think that's what this part is called) just comes right out. Is it possible for me to shorten this? Would someone want to trade?
Btw i have the manual with a blow up diagram of the internals in case anyone is interested. I can put it up.
