Which feature on a cartridge base indicates the manufacturer and caliber?

• A. Primer
• B. Case
• C. Headstamp
• D. Bullet

Answer: (C)

The marking on the base of a cartridge, known as the headstamp, is what identifies the maker and the caliber. It’s stamped into the metal around the primer pocket and usually shows the manufacturer's initials or name along with the caliber designation, sometimes plus a year or lot code. This is the best answer because the headstamp is specifically designed to convey who produced the cartridge and what caliber it is. The primer’s job is ignition, the case is the container, and the bullet is the projectile—none of those inherently indicate the manufacturer and caliber in the standardized way that a headstamp does.