Nothing in NY surprises me, but do you have a reference? In NYC, rifles, shotguns and handguns require registration with the NYPD, IIRC.
NY Penal Law S 265.00 Definitions.
As used in this article and in article four hundred, the following terms shall mean and include:
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3. “Firearm” means (a) any pistol or revolver; or (b) a shotgun having one or more barrels less than eighteen inches in length; or (c) a rifle having one or more barrels less than sixteen inches in length; or (d) any weapon made from a shotgun or rifle whether by alteration, modification, or otherwise if such weapon as altered, modified, or otherwise has an overall length of less than twenty-six inches; or (e) an assault weapon. For the purpose of this subdivision the length of the barrel on a shotgun or rifle shall be determined by measuring the distance between the muzzle and the face of the bolt, breech, or breechlock when closed and when the shotgun or rifle is cocked; the overall length of a weapon made from a shotgun or rifle is the distance
between the extreme ends of the weapon measured along a line parallel to the center line of the bore. Firearm does not include an antique firearm.
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11. “Rifle” means a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned and made or remade to use the energy of the explosive in a fixed metallic cartridge to fire only a single projectile through a rifled bore for each single pull of the trigger.
12. “Shotgun” means a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned and made or remade to use the energy of the explosive in a fixed shotgun shell to fire through a smooth bore either a number of ball shot or a single projectile for each single pull of the trigger.