Wasn't sure if I should post this here or in the NFA forum. Mods, please move if necessary.

At the local gun show today I saw a number of S&W M&P22's with what appeared to be an A1 flash hider. According to S&W's website, it is an "A1 style comp". Does anyone know if a Gemtech HALO would mount to it? Any issues using a HALO with a .22?