First of all I have broken no laws. Suppressors are a completely unregulated and legal item in New Zealand.
I few weekends ago I was at the range with a few mates plinking set steel targets with my .22 when I realised that I had an empty 600ml Pepsi Bottle and roll of insulation tape. So we decided to make a comparison of my mates suppressor and my Pepsi bottle. It works quite well (get's bonus points for double-take effect when people see it, as well).
Anyway, next range trip I took a tapered reamer and took a hole out of the centre of the bottle cap to allow me to just wedge it into position on my bbl and not worry about tape.
Anyway, I have two questions about the US Legal implications of this.
Firstly, Could possession of tape and an empty plastic bottle be called constructive intent if they really wanted to throw the book at you?
Secondly, Would the bottle cap or the actual bottle be considered the suppressor? E.g I know a threaded barrel could be used for a muzzlebrake or flash suppressor and in itself not illegal but the suppressor that attaches to it requires a Class 3 Permit.
P.S. If you're unfamiliar with the registered shoelace, here it is
Edit: And this would be better in the NFA section not GDF.