If I remember correctly he designed the .44 magnum to fire his 250 grain cast semi wadcutter bullet at about 1250 fps. When Remington actually created the .44 magnum cartridge it was 240 grains JHP at 1450 fps and these were also little harder on the early Smith M29s longevity if a huge amount of ammo was run through them. Elmer seem to always load his slightly less powerful round and indicated it was about the perfect load for everything he shot with it from rattlesnakes to Elk.