Here is how it works.
First, if you buy from a dealer, they will create all the paperwork and shepherd you through the process. So you don't need to really know anything.
I STRONGLY recommend talking to "big Gary" at Newington Gun Exchange. He is a good guy and knows a lot.
The first NFA item I purchased was done via an individual purchase. I had to get my chief LEO to sign off on it that there weren't any laws prohibiting possession in my town.
I also had to submit the standard stuff. (I believe finger prints and a photo, but its been a while so I forget)
It was a big pain in the ass even though my CLEO didn't have any problem with the transfer.
I personally know people for whom the CLEO refused to sign off even though there were not any statutes prohibiting possession in their town.
So for all subsequent NFA transactions, I set up a revocable trust for the sole purpose of owning NFA firearms.
An SCorp or LLC will work also, but a trust is MUCH easier, and it does not involve any yearly fees.
Now, I can do a form 4 (transfer) or a form 1 (if I want to make a standard rifle into an SBR) in about 20 minutes. NO CLEO signoff, no photo, no fingerprints.
Again, this is a convenience for me. My local cops don't have a problem with this stuff and are happy to do a set of prints. But if you live in a place that tries to make this stuff difficult, then a trust is the ONLY way to go.
OK. So the next question is how do you do a trust.
The answer is that it depends. If you want to own a suppressor or two and maybe register an AR lower to make an SBR, then you might want to use Quicken Willmaker. Its cheap, and the ATF seems to approve trusts made with it.
Because I knew I'd end up owning a bunch of stuff, I spent the money on having an Atty set up my trust. I didn't want there to be trouble down the road after I die.
So now my trust owns all my NFA firearms.
Also, the trust makes it easier for you to let your friends borrow your NFA firearms. Very simply, as the Settlor of the trust, you make your friend a trustee. Then they can legally possess the NFA items.
It paid dividends for a friend who went through a nasty divorce. He wanted to move all his guns out of the house. The NFA stuff would have presented a problem if it weren't for the trust. He simply added a friend to the trust and moved all the NFA stuff out of the house.
Let me know if you have any more questions, I'd be happy to answer them.
Here's some porn for your enjoyment. Its only a M11/9 with a Lage upper and a YHM suppressor. But with the .22 kit in it its just as much fun to shoot and cheap enough so I don't think about money. Lets face it, a machine gun is a nothing but a toy intended to put a smile on the face of anyone who uses it):