What counts as a handgun, rifle, or shotgun in NH?

I've tried searching but I have no luck with search engines and all that. What are the actual laws regarding classification? I heard that for a handgun it has to have a barrel under 16" but does that mean a SBR is a handgun by state law? What about the others?

I didn't see a definition of rifle or shotgun, but here's the definition of pistol or revolver:

159:1 Definition. – Pistol or revolver, as used herein, means any firearm with barrel less than 16 inches in length. It does not include antique pistols, gun canes, or revolvers. An antique pistol, gun cane, or revolver, for the purposes of this chapter, means any pistol, gun cane, or revolver utilizing an early type of ignition, including, but not limited to, flintlocks, wheel locks, matchlocks, percussions and pin-fire, but no pistol, gun cane, or revolver which utilizes readily available center fire or rim-fire cartridges which are in common, current use shall be deemed to be an antique pistol, gun cane, or revolver. Nothing in this section shall prevent antique pistols, gun canes, or revolvers from being owned or transferred by museums, antique or arms collectors, or licensed gun dealers at auctions, gun shows, or private premises provided such ownership or transfer does not conflict with federal statutes.

You must start with the Federal definitions, (http://www.atf.gov/publications/download/p/atf-p-5300-4.pdf)then work to NH state variations. No state that I know of is less strict than the Federal definitions for Rifle, Shotgun, Handgun, and Federally controlled NFA firearms. (Nor can they be, I believe.)

States like my Michigan are a bit more strict, in that they classify any shotgun that otherwise is a Federally legal shotgun (18" barrel, 26" overall) that has an overall length less than 30" as a handgun.

States can define these terms any way they wish; the federal definition applies to federal law, and the state definition applies to state law. They don't have to be aligned, but the world makes more sense when they are.

Take the New Hampshire definition of pistol or revolver (they don't define handgun at all): it hinges entirely on barrel length, and completely ignores the defining characteristic of a handgun under federal law, that is, a firearm intended to be fired with a dingle hand.

Looks like according to state law, I can have a loaded SBR in my truck.