Originally Posted by
Bigslug
la5676, If the load data is on the box, that may be a clue as to what your father had in mind, but if all you have is "rifle load", it could mean:
Load worked up for a rifle's barrel length.
Load worked up for a specific gun (as in, he had five revolvers, but only one rifle)
Might have been uncomfortable to shoot in a handgun.
Worked it out to feed in a rifle (not an issue with revolvers so long as bullet nose length isn't excessive)
The Lyman manual lists the .357 and several other popular levergun/revolver cartridges in two separate sections. I've not yet delved too deeply, but if one had no intent to shoot the ammo through a handgun, powders with slower burn rates could be used to maximize a rifle barrel's velocity potential, but might lead to an incomplete burn if tried in handguns.