check with the prosecutor's office
Unfortunately yes. But there are ways around it.
if a gun has a threaded barrel, (required for a silencer) it is classified as an "assault weapon" and is illegal in California.
yes silencers are illegal in montana
Depending on who you are, no.
That is an extremely difficult question to answer with any accuracy, but the basic answer is, just like anything else that is illegal, somebody in the legislature doesn't think you should own one, so they passed a law saying you can't.
Depends on who is using them and for what.
Silencers are illegal in SOME states for the general public, but only a few. See link below
No Virginia restrictions, but you must comply with Federal law.
JUSTICE BROWN
YES
Yes, provided you have complied with the FEDERAL law regarding suppressors. This is governed by 18 PA.C.S.§ 908.