Originally Posted by Axel
Strap one to a firearm, and if it muffles the report by 1Db, then yes. Any of the mundane items mentioned above--pillow, potatoes, pop bottles--do become silencers when used as such.
...vs a purpose-built item to muffle a projectile, which may not need to be actually used as such for NFA regulations to apply.
It is a legally murky topic. "Law" and "intent" are murky subjects. How does the law define "intent?" Consider that in many jurisdictions, you can be charged with D.U.I. simply for sitting in the driver's seat of a parked car with the key nearby. Maybe you 'intended' (English) to sleep it off, but in court, your 'intent' (Legalese) is defined for you by statute.
Another example: in Virginia, certain knives with assisted-opening blades are not illegal to possess... however, they are illegal to sell, and possession alone, according to statute, is prima facie evidence of intent to sell. In other words, you can be arrested, charged, and convicted* of selling an assisted-opening knife simply for possessing one. Why the legislators did not simply outlaw possession, I haven't the foggiest idea.
The point is that law need not be logical, and it need not conform to commonly understood definitions. If 900 pages of law, 12 volumes of regulations, and a panel of justices decide that the sky is green, they can do so if they are inclined to. People laughed when Clinton quibbled over the definition of the word, "is," but he really only used standard legal tactics.
*...and here's a demonstration of the risk of amateur lawyering! I just re-read parts of the Wikipedia article on prima facie, and apparently it means that possession would be enough to take a case to trial, not necessarily convict of its own weight.
As I've said before, I think that this is and should be legal, but not sure enough to do it myself.