Winchester, Mossberg, Remington
The answer would requires a few hours of research.
Only if that is what is marked on the barrel. 22 LR and 22 WMR are not interchangeable.
win. mag. rimfire
Yes
As in .22 WMR? That is the full name of the cartridge- the .22 Winchester Magnum Rimfire- usually called the .22 magnum
The Winchester Magnum Rimfire is a larger round, and is capable of producing twice as much energy as the .22lr. I do believe that Ruger is making a rifle capable of handling the .22WMR, but a standard .22lr rifle is incapable of safely firing the .22WMR.
There is a .22 WRF, and a .22 WMR. WRF is Winchester Rimfire. Bigger than a ,22 Long Rifle, but shorter than a .22 WMR- Winchester Magnum Rimfire. If someone is using the term .22 MRF, it is an inaccurate term.
No
.22 Mag shell only.
Yes
Winchester Magnum Rimfire (WMR)
No. The case of a 22 WMR is longer than that of a 22 lr, so the cartridge won't fit in a rifle that is chambered for 22 lr.