A .22 mag is both too large and too long to fit into a .22LR chamber.
There are some .22 revolvers which have a cylinder for each. The tiny difference in the bullets diameter does not seem to hurt accuracy too much.
In short if you have a Ruger Single Six with both cylinders, the WRF and Magnum will both work in the same cylinder. Neither will fit the .22LR cylinder.
I am not basing this on theory. I have fired lots of WRF in magnum chambers.
Ok, I understand that. I have both kinds of rifles. My question is: can I shoot a .22WRF in a rifle chambered for .22LR?
I think you are confusing 22WMR and 22WRF. They are not the same. WMR is to WRF what 22long is to 22short.