Answer:
WMR stands for Winchester Magnum Rimfire- and is the proper name for the 22 Magnum. They are the same cartridge. The 22 WRF is the Winchester rimfire, and is a shorter, less powerful version of the 22 magnum.
First answer by C3shooter. Last edit by C3shooter. Contributor trust: 352 [recommend contributor recommended]. Question popularity: 2 [recommend question].