Well, I really didn't think that the ATF would have the cojones to change their minds for the fourth time and ban the use of pistol arm braces...they're legal, they're not legal, they're legal, they're not legal. Anyway, now I've got to either remove the arm brace from my SIG MPX or register it with the ATF within 120 days or basically I become a felon. I like a stock on the MPX, so I've decided that I will register it, and I have gone online and set up an account with ATF eforms. At least the AG won't make me pay the $200 tax fee! Besides, once my MPX is registered as a SBR, I can legally put on a real collapsible/folding rifle stock. I know, I'm breaking the NRA's and 2A rules to fight back, but I don't care if ATF knows that I have this one firearm. With my ATF eforms account, I can also quickly register a suppressor (or suppressors) in the future. LOL, please no hate letters! Thoughts?