If a guy (LOL) put one of the minimalist sized fore grips or angled fore thing on a rather large pistol would that be somehow a violation? No brace or stock. Asking for a friend before he does something stupid...

Is it worth going to prison?

If the answer is anything but NO, run away.

FWIW, I believe ATF “guidelines” mention 90 degrees, but do you trust the ATF to stick to the same story?

A vertical foregrip on a pistol is illegal, brace or not. That makes it an NFA item called an AOW.

If it’s a 90 degree grip, it’s a nope as long as the gun in question meets the legal criteria to be a pistol. If it’s an angle other than 90 degrees, it’s legal. That’s my understanding, and why there’s so many angled grips out there.

Thanks folks! I will tell him it is a no go on the grip and probably not a good choice on the angle grip.

26 U.S.C. § 5845(e) is interpreted by BATFE to define a pistol as a short firearm intended to be fired with one hand and has advised installing a vertical fore grip on a handgun is ‘making’ a firearm requiring registration with ATF’s NFA Branch.

(see Adding a Vertical Fore Grip to a Handgun, U.S. Department of Justice, Bureau of Alcohol, Tobacco, Firearms, and Explosives (May 4, 2006), http://www.atf.gov/press/relea...-adding-vertical-for e-grip.html.)

As described alove, I agree vertical foregrips put you in NFA territory. Angled grips are a gray area; you'd probably win something like a Magpul AFG but it's doubtful beyond that.