Bare bones explanation, Each NFA item requires its own tax paid and its own set of paperwork. In the case of silencers, they can be freely used on any host gun (within that silencer's capabilities) without any further paperwork. SBR's and MG's need their own tax paid as well, but once they are...
This is a legit concern. Pleas everyone read up on it and comment. Even if you don't own any Nfa items, you might want to one day!
Please please please, at minimum copy and paste what he has provided.
As others have said, ANY transfer of a silencer is the same. A form 4, a $200 tax, and about a 6-8 month wait.
There is NO huge investigation or anything. It is essentially the same background check run on you when you purchase a gun from an FFL. It just takes a lot longer.
Spread the word...