As far as firearms go this is my understanding:
If it was made prior to 1899 it's generally considered an antique. However cartridge firearms for which ammunition is readily available are NOT considered antique. . . .
Can you cite an ATF ruling or regulation that says an antique isn't an antique if it take readily available ammo?
Firearms Verification
National Firearms Act Definitions
Antique Firearm
26 U.S.C. § 5845(G)
For the purposes of the National Firearms Act, the term “Antique Firearms” means any firearm not intended or redesigned for using rim fire or conventional center fire ignition with fixed ammunition and manufactured in or before 1898 (including any matchlock, flintlock, percussion cap or similar type of ignition system or replica thereof, whether actually manufactured before or after the year 1898) and also any firearm using fixed ammunition manufactured in or before 1898, for which ammunition is no longer manufactured in the United States and is not readily available in the ordinary channels of commercial trade.
