bigred0383:
.45 ACP by modern standard is quite low pressure - 21,000 PSI, which although considerably higher than the .44 Special & .45 Colt that that particular gun was originally designed to shoot, is only marginally higher than the .38 Special round which was being manufactured on the smaller K frame at the time.
S&W were confident enough to buy back a large number of unused guns from the army after WWII & resell them to the public.
Your gun is built on the large N frame, which in the 1930s was used to chamber the 36,000 PSI .357 magnum and in the 1950s to chamber the .44 Magnum. So the frame is strong enough.
Because heat treating of cylinders was not introduced until 1917-1920, depending upon the model, I can't tell you wether your cylinder is heat treated. Because of this I would say that your gun is safe to shoot with standard pressure ammunition, but I would avoid PlusP ammo.
There is a revolver checkout thread stickied at the top of this sub forum. If your gun passes it then it is safe to shoot.