No, it is/was not.
yes.The Winchester model 9422M was chambered in .22WMR.
The letter M after the model number 9422 indicates that your Winchester lever action rifle is chambered for the 22WMR(Winchester Magnum Rimfire) cartridge.
As the number 3 indicates,your Winchester model 42 can chamber either 2 1/2in,or 3 inch 410 shotgun shells.
Winchester stopped the regular production of 20 gauge in 1963 and the 20 gauge magnum shell wasn't introduced for several years later.
The winchester model 670,and magnum models were made from 1967-1973.
There was no 300 Winchester Magnum cartridge in 1939. A 1939 Model 70 would be marked "300 Mag"...and it will be chambered for the 300 H&H Magnum cartridge. There was no other 30 Magnum cartridge in 1939 in the Model 70. The 300 Winchester magnum cartridge was introduced in 1963,...the last year the Pre'64 Model 70 was made. Your 1939 Model 70 may have had a later barrel swapped in to it. 300 Winchester and 300 Win Mag are the same cartridge.
Your Winchester model 70 bolt action rifle that is chambered in .300 Win Mag,has a twist rate of 1 in 10.
it stands for Winchester Magnum Rifle.....it takes a 22 MAG BULLET
The only Winchester chambered in 45-60 was the Winchester model 1876 rifle.
at least 10000
This question would be better directed to a qualified gunsmith.The .22 magnum round is operating at a higher pressure then the regular .22 long rifle cartridge.He would be better able to know if the Winchester model 72A could with stand the higher pressure involved with this rechambering.
Winchester model 275 is a .22 cal. magnum (WMF) slide action rifle. It is identical to the model 270, which is chambered for standard .22 cal. short, long and long rifle. Though no longer in production, it is following its predasessor, the model 61 as a sought after collectors piece.