Re: dumb full auto question
A reliable 10/.22 NFA gun is going to cost a LOT. Previously, meaning about five years ago when I was still shooting select-fire guns (owned a half dozen, shot more), I recall one selling for around $8k. This was a John Norell conversion, considered by many to be the best.
Another option, and there are a lot more of these available, is the American 180. Still pricey, but more were manufactured and they do come up from time to time on the NFA boards, but you're still looking at - easily - $5k to $8k.
A good investment. And there are 300 (360?) round drums available. You can literally write your name on a berm with one of these. Takes forever to load by hand (some special tools were available at one time for reloading), but is a LOT of fun to shoot.
Good luck finding what you're looking for.