The very first thing, it has to be transferable. However it works, the ATF has to have it as a recorded weapon, weither it was a bring back, registered before the old cut off date etc. I looked at an AK a few years back to find out it was never documented, I just walked away and deleted the guy out of my phone book.You just gotta get a special permit for it, right?
I agree, a friend of mine has a slide fire on his AR and it screams. It works very well. Never jams or causes any hiccups.Just buy an ar-15 and buy a slide fire stock. Bump fire and be done. Not sure how good they are, but beats dealing with the hassle of class 3 and YouTube has some cool videos! Just stumbled on them today looking at ar pistol vids.