S&W .22 mrf?

[powernoodle]

I inherited a S&W model 51 6-shot revolver which is marked ".22 MRF CTG".

So is this S&W's designation for 22 Magnum and 22 Win Mag? I'm just trying to figure out what kind of ammo this gun will eat.

Edit: I think I figured out that 22 MRF = 22 Magnum = 22 Win Mag.

Thanks!