A:
Definitely NOT,although the bullet calibre is the same (and the very same bullet used by most of the producers) the overall cartridge length is considerably shorter. If fired in the HMR chamber the HM2 case would surely come apart and cause dangerous consequences. I'm no ballisitician so I don't have details, but I know it would be VERY unsafe!
How about a GREAT website for rinfires?---- just search "Rimfire Central"--- all kinds of shared info!