And my advice is worth what you pay for it, but here it is. As I understand it, the Feds consider the "intent" to silence a firearm, without their prior approval, to be a crime.
This view covers alot, even homemade "silencers", even ones that don't actually work are prosecutible, because "intent" is a crime, along with posession.
Then there is the whole "creative posession" or "constructive posession" thing. The legal idea that since you have the parts (and tools) to make something illegal that it is the same thing as having the illegal thing. Sometimes this gets shot down in court, but other times it flys. Why risk it?
And finally, your tax stamp and paperwork is your proof that you have complied with the law. You would have to produce them for any LEO who asks, or face arrest. You might have to show them to the range officer/range managment in order to be allowed on their range, but that would be a private matter between you and the range.
If you want actual valid legal advice, find (and pay) an attorney who understands Fed/state gun laws. That way if you get bad advice, at least you have the benefit of knowing you were lied to by a professional.
