Cartridge
A complete round of ammunition — case, primer, powder, and bullet assembled together.
Not to be confused with “bullet” (just the projectile) or “shell” (a shotgun term). A 6.5 Creedmoor cartridge is the whole assembly, ready to chamber.
Cartridges are named after the case, not the bullet — .308 Winchester refers to the case design, which can be loaded with bullets from roughly 110 to 220 grains.