The basic problem is it's a Federal crime. That trumps state law, if on the same point. Your chances of a fair or reasonable deal in Federal court is much less then in state court. We used to somewhat negotiate in pretrial in S.F., but, if you go into Federal Court, it's take it or leave it, and, most of the time, you have judges elected for life, who do what ever they want, and don't care much about getting reversed on appeal, so, they are free to make up whatever they want.
If you defend yourself with a silenced weapon, in your home, depending on Castle Doctrine, or local law, you could be prosecuted for some form of homocide, or assault and battery. If found guilty in state court, or if the evidence fits, you could be yanked up to Federal court, prior to trial, for prosecution there.
The bottom line is it's an absurd law, that makes no sense at all. Silerncers, in particular on hi-powered rifles, that combine the features of a muzzle brake, reducing recoil and lift, combined with reducing noise, are a WONDERFUL
and effective technique for protecting the shooter, and being able to enjoy the rifle.
Consider when this law was passed: during the FDR administration, and, you will see why it still exists. The FBI, BATF, and the Federal bench, has to have something to enforce to justify their bloated existence.
Someone will have to challenge the law someday, but, more likely, it will be plead out, so the law continues...