Ok so first off I'm not a FFL, but I am a NH resident. If I want to sell a AR lower to someone out of state and I mail it to their FFL can I use USPS? I've read a lot of conflicting information that Long Guns and Shot Guns are ok BUT does USPS consider a AR lower concealable? IE: same as a Handgun? Just trying to stay out of trouble and do things right.