Massachusetts Law defines ANY component as "Ammunition" :
Section 121. As used in sections 122 to 131P, inclusive, the following words shall, unless the context clearly requires otherwise, have the following meanings:-
“Ammunition”, cartridges or cartridge cases, primers (igniter), bullets or propellant powder designed for use in any firearm, rifle or shotgun. The term “ammunition” shall also mean tear gas cartridges, chemical mace or any device or instrument which contains or emits a liquid, gas, powder or any other substance designed to incapacitate.