Yeap

Its great to find loopholes in the laws. That's the fun part.
Rather than make lawyers richer, I prefer to spend my cash on more productive endeavors: firearms, accessories, ammo, cleaning supplies, cases, targets and frames, gas for the car, vacations to areas I can enjoy my guns, etc.
Pushing the envelope of the legal system might give you a stiffie, but at some point in time you will more than likely have the item in question confiscated if it isn't registered until a judge hears your case. You and your lawyer will have to appear in court, and you'll waste valuable time preparing ... all for a foregrip on a Glock?
If the firearm in question all on its own were more "fun" (explosive, full-auto, 15+ round mag, sound suppressor, etc.), maybe I could see the point. If it's purely a matter of principle, then there are PLENTY of other rights and firearms under attack by the anti-gunners to defend. No need to invent another weapon to have to protect from a potential ban!
Just my opinion. If this sort of "windmill jousting" trips your trigger, then have at it!
