[joering2]

Just a nit pick: the government only knows where each item is so long as the owner has reported it moving around, as required per ATF laws. Wanted to mention this because someone may imagine there is a GPS attached to lower receiver of FA. If you travel with your fully automatic you need to report it to your local sheriff office (stating purpose as well); also when you move to a different city/county/state.

Another nit pick: the approval is not some sort of interview or questionnaire as of why you need it. There is so-called ATF stamp (i.e. $200 for silencer) than you need to submit altogether with FBI fingerprints. These days mojority of ATF applications is registered thru "trust", instead of an individual. This creates all sorts of issues for LE in case they want to run extra background on you etc. So 90-something % of people chose $50 ATF "trust" that Sheriff cannot technically decline over the other option which is petition as individual and getting close to 100% chance of denial. The biggest hurdle is not some LE not liking your tattoo, its that ATF has a year long backlog. So you pay for your FA $25,000 today but its only delivered to your local licensed gun store, and they won't let you pick it up until ATF sends them document with green light. That take sup to 1.5 year these days. You can come and touch it and take few photos but they will not allow you to load it of course, or to take it out (including shooting range).

Finally, as OT mentions fixed supply, a so-called lower receiver of a fully automatic gun, a piece of metal not much bigger than a door handle (which does not even have any fancy engineering) is literally the most expensive piece of metal that you can buy on American soil. Some examples in extremely good shape go for $35,000 these days (check gunbroker dot com)