I have that same rifle. It belonged to my grandfather, then my dad, then me. It will not feed or eject any other .22 rimfire ammo (my dad tried before he knew what he had) but it will make them go bang. /ubbthreads/images/graemlins/laugh.gif
.22 WRF ammo isn't too hard to find. Winchester produces a limited run of ammo every couple of years. If you can find some, stock up. I bought a case from Cabelas last year. You can often get it at gun shows - if you can stomach the ninjas, dragon slayers, and paramilitary nut jobs.
I can't remember what I paid for the ammo, but I don't think it was too bad.
Good luck.