What is the difference between centerfire and rimfire ammunition?

• A. They differ only in color.
• B. Centerfire primers are in the center of the cartridge; rimfire primers are in the rim; centerfire is generally more powerful and reliable for most firearms.
• C. They are identical in all aspects.
• D. Centerfire is always safer to handle than rimfire.

Answer: (B)

The key idea is where the primer is located and what that means for ignition and performance. In centerfire ammunition, a primer disc sits in the center of the cartridge base and is struck by the firing pin to ignite the powder. This design allows higher internal pressures, stronger cases, and reliable ignition, plus easy reloading because primers and cases can be renewed as needed. In rimfire ammunition, the primer is formed into the rim around the base, and ignition happens when the rim is struck; this limits the pressures that can be generated and makes rimfire rounds inexpensive and small in caliber, with little practical reloading. Because centerfire primers are in the center and enable more power and reliable ignition for most firearms, that choice best captures the difference.