In most states, yes. Silencer is a misnomer, you can't totally silence any round, but we are talking about the same thing. Suppressors are very legal in Florida, just like full auto machine guns. Yes, full auto. It requires some specialized paperwork, some waiting time, and a background check, but that is about it. Only slightly more complicated than getting a concealed weapons permit. I am unsure of the laws of Pennsylvania, but a quick check with your local gun shop should get you the info you need.
My apologies to the OP for hijacking your thread
