Short story... I know the guy who started the latest bump fire craze (poor man's machine gun). He can do it on almost any rifle and has just about perfected it. He actually can shoulder the weapon and do it. There was a bunch of talk about legality etc. He wrote the ATF, and on official letterhead it says it is not illegal. That was several months ago, unless someting has changed since. Go out, practice, have fun! ;D