well a .22 LR is a rimfire
there is also a .22 Win Mag that is also a rimfire though
still when i hear 22 rimfire i think 22 lr, usually people (here anyway) say 22 mag when they are talkin about its larger cousin
There different types of 22 rimfire, as many folks have already noted. You need to be sure which you need. Eg. 22 WMR, 22LR, 22 short. Within 22Lr, there are other subsets, like for the Hyper velocity rounds (which can ruin a High Standard 22 target gun - specifically designed for 22 LR in regular velocity).
yes my .22 LR conversion unit states that you need high velocity and that .22 normal or hyper velocity wont ruin it but you wont experience good results with it and i have found that to be true
can get good accuracy w/ high velocity and cant group 3" with hyper velocity at 25y