Which of the following best describes rimfire ammunition primer location?

• A. In the rim of the casing
• B. In the center of the cartridge
• C. Under the primer cap
• D. In the stock

Answer: (A)

Rimfire primers are located in the rim of the cartridge base. The priming compound is distributed around the edge of the rim, so when the firing pin hits, it crushes that rim and ignites the powder behind it. This placement is what distinguishes rimfire ammunition from centerfire, where the primer sits in the center of the base under a primer cap. The other options don’t describe where the primer is found: placing it in the center would be centerfire, suggesting something under a cap isn’t how rimfire primers are arranged, and “in the stock” isn’t part of the cartridge at all.