The 22 Magnum and the 22WMR (Winchester Magnun Rimfire) are one and the same. The 22 WRF is slightly shorter than the Mag and uses a heavier (45 gr) bullet than the Mag. I say uses because Hornady is once again making 22 WRF. When I was a boy I had a 22Mag/.410 Savage 24 O/U that we hardly ever shot the 22 Mags in. Used it with the WRF's as a squirrel rifle; it being a cleaner killer and more powerful round the the 22 Long Rifle. The 22 Mag back then was only available as a Hollow Point and blew every thing up. The 22 WRF had two loadings: a 40 gr HP that was discontinued by the time I shot the cartridge and a 45 gr flat nosed truncated cone bullet at 1500 fps that was a great small game round. I duplicate that load in my 22 hornet using 4.0 grs of Unique and the Speer 46 gr flatpoint bullet designed for the Marlin lever in 218 Bee. With all the re-newed emphasis on rimfires being shown these days, nice to see the re-birth of a cartridge that can be used for edible game. Don't know if anyone will ever make a rifle these days for the 22WRF, but if they did, I'd sure buy one, and not for just nostalgia. It was/is a great little cartridge.