I don't have to pick up a glowing horseshoe to know it's hot.
Edit to add:
I guess it's rude of me to not explain. I apologize for coming off somewhat brusque.
I'm not part of the NFA world, but I do read about what interests me -- a lot! One of the secret legends in that world was Kent Lomont, who passed away just over a year ago. While little known to the general gun community, and completely unknown to the Fudd world and non-gun people, to say that he was legendary with machineguns and ammunition development would be the epitome of an understatement.
Have you ever read
Unintended Consequences? Let's just say that John Ross would have had to tone down Kent Lomont to make him a believable character.
He actually did inspire some of the characters and events in the novel, and is referred to in passing, which brings us back to Knob Creek...
In 1986, we had changes to the Gun Control Act which are positive for the vast majority of gun owners. Foremost is what is commonly called "FOPA", the provision that guarantees safe passage when transporting guns through a jurisdiction where they would otherwise be illegal. Also, the restriction of only buying rifles or shotguns from dealers in states contiguous to your state of residence was lifted; now, you can buy them in any state, so long as the sale is legal in both states. These were good things, but the trade-offs were ghastly.
It also made huge negative changes for the tiny minority of gun owners who work or play in the full auto world. It banned machineguns made after May 1986 from possession or transfer to any private citizen who wasn't a Class III dealer. Licensed manufacturers could no longer make machineguns without paying the Special Occupational Tax, which is an extra $1,000 per year on top of the Manufacturer FFL.
These changes created a huge rush to make and register MG receivers before the cutoff date, and also a very healthy black market to register receivers made after that date, or which had been made earlier but never registered. The market for illegal MGs had always been small, because they were neither popular nor expensive, but the newly restricted market created a huge surge in price for those that could be legally transferred.
And so it was that a fellow approached Kent Lomont at his table at Knob Creek, and asked how to register MG receivers. Kent said he couldn't help him, but a fellow named Hunter had papers. That was it.
Hunter was an informant, and the whole lot were prosecuted, including Kent Lomont, for conspiracy to violate the Gun Control Act and National Firearms Act.
Long story short: go to Knob Creek, play with the goodies, have fun, but don't buy or sell anything, or talk to anyone about anything of questionable legality.