[jwparkerjr]

I’m curious, where is the primer on a rim fire cartridge. I know the difference between them, but not sure how the rim fire works, despite the fact I grew up firing thousands of them on the ranch as a kid.

Thanks!

[Buffalo Head]

There is not a separate primer, per se, in rimfire ammunition. Primer mix is forced into the internal cavity formed within the rim of the shellcase. The firing pin in rimfire firearms crushes the rim, which ignites the primer mix contained in that peripheral cavity which in turn ignites the propellant powder.

[calex59]

The primer compound is spun up into the outer edges of the rim, inside the case of course, so when the firing pin drops on the edge of the rim the primer compound ignites. Primer compounds are actually types of fulminates.