Yes--I have a friend who has a 721 chambered for 300 super mag
The model 721 was produced from 1948 to 1962
Winchester Model 1200
A Winchester Model 70 is a rifle.
Made before 1962
Your Winchester model 42 was made by Winchester in 1935.
The Remington Model 721 in .300 H&H was manufactured in 1948 with a 24" or 26" barrel.
Winchester did not make a Model 30
No
Your Winchester model 1894 was made by Winchester in 1940.
Your winchester model 70 was made by winchester in 1965.
your winchester model 1894 was made by winchester in 1979.
your Winchester model 1894 was made by Winchester in 1928.