As for reduced recoil keeping you on target. When those came out Trail Boss powder didn't exist. So it made sense to have a 38 special only version.swany said:That .100 or 1/10th of an inch can mean something as far as speed and mods are concerned.
Convert your Marlin with a short throw lever and it changes a lot as far as speed is concerned.
The .38 only is a good idea a lot of shooters use the shorter round for less recoil, faster cycling.