It will shoot 22Mag!
WMR= Winchester Magnum Rimfire.
So any 22Mag bullet from the shot shells, the high velocity 30's ( 30, 32, 33, 34, and 35 grain of various bullet designs) ( these equal or surpass the 17HMR out to 100yards) up to the 40 grain standard rounds in JHP, FMJ, and Soft point and up to the 50 grain Federal JHP rounds.
You can not shoot the 22 CB, Short, long, or long rifle in the gun. They are a smaller diameter and people have made the mistake in a handgun and not had any problems but with a rifle expanding gases may come back and hurt you.
A 22 mag is not like a 357 mag that can shoot 38Spl or 38S&W.
The 38 special version of WMR is the 22WRF round that is a little hotter than 22LR but not much.
I guess you could shoot 17HMR through it but it will not be accurate. But they will fire. Would be like shooting a 270 out of a 30-06 rifle or shooting 357 sig out of a 40S&W handgun.