Encyclopedia
Rimfire 101
Everything rimfire, explained in plain English with a source for every fact: how rimfire works, where it came from, the cartridge family, actions, uses, competitions, ammo terms, safety and storage.
What is rimfire?
How a rimfire cartridge fires, why the priming compound lives in the rim, how that differs from centerfire primers, and why rimfire cases aren't practical to reload.
Rimfire history
A sourced timeline of rimfire cartridges: Flobert 1845, .22 Short 1857, .22 Long 1871, .22 LR 1887, .22 WMR 1959, 5mm Rem Mag, .17 HMR 2002, .17 HM2, .17 WSM and .21 Sharp.
Rimfire cartridges
Every common rimfire cartridge in one table with sourced bullet weights, velocities and pressures: .22 CB, Short, Long, LR, WMR, .17 HM2, .17 HMR, .17 WSM, .21 Sharp and 5mm Rem Mag.
Rimfire actions
How bolt-action, semi-automatic, lever, pump and single-shot rimfire rifles differ, what each is good at, and current examples with sourced specs.
Rimfire uses
The main jobs for rimfire rifles: plinking, small-game hunting, pest control, training for centerfire shooters and youth programs, with links to our guides.
Rimfire competitions
How the main rimfire disciplines work: NRL22, PRS Rimfire, ELR22, ARA and RBA benchrest, ISSF 50 m smallbore and biathlon, with links to each governing body's rules.
Ammo terminology
Plain-English definitions of rimfire ammo labels with sourced examples: subsonic, standard velocity, high velocity, hyper velocity, match, lead vs plated, heeled bullets, CB and shotshell.
Rimfire safety
Core rimfire safety: safe direction, backstops and how far a .22 can travel, hearing and eye protection, hangfires, and why 'it's just a .22' is a dangerous idea.
Rimfire storage
How to store .22 ammunition and rifles based on SAAMI's guidance: cool and dry, original packaging, away from solvents and heat, separate from firearms and secured from children.
Misfires and dry firing
Why rimfire misfires happen, how long to wait after a failure to fire, whether dry firing damages a .22 (Ruger and CZ manual quotes summarized), and snap caps.
Ammo shortages
A short sourced history of the 2013 and 2020–21 .22 LR shortages, why rimfire production is hard to expand quickly, and practical ways to buy and store ammo.
Where to shoot and legal basics
Where you can shoot a rimfire (ranges, clubs, public land, private land), plus the general legal basics on buying and hunting, with links to our detailed guides. Not legal advice.
Rimfire FAQ (40 answers)
What, why, when, how and where, all sourced.
How we research: primary sources first (SAAMI, makers, governing bodies), encyclopedias second and cross-checked. Where sources disagree we say so. Our method.