I too have a Winchester Model 74 Semi Automatic rifle, mine is in .22 Long Rifle caliber. The rifle was made between 1939 and 1955. They were made in both .22 Short and .22 Long Rifle. (introduced in 1940). I wouldn't think that the two calibers are interchangeable (different chamber lengths) and the higher powered .22 Long Rifle fired in a mechanism designed for a .22 Short could cause the rifle to jam and possibly damage the action.