To the OP: The reason you are missing the "Magnum" in your loads is because you are, in effect, loading a 38/44, not a .357 Magnum.

The 38/44 pushed a 158 grainer out the door at about 1,150 fps.

The original Magnum pushed a 158 grain bullet out the 8 3/4 inch barrel at 1,550 fps.

If you want to see about what the original Magnum feels like, try Buffalo Bore SKU 19C/20.