text: The genesis of the .410 does not coincide with the heyday of shotgun design, which occurred from circa 1850 to 1870. It wasn't until about 1900 that the cartridge is making its appearance in catalogs and the proof houses of England. No one today knows who invented it. There is a good amount of speculation that the .410 was originally a rifle caliber, the .444 Marlin. This is probably so, due to the rather recent discovery of older "rook rifles" that were originally rifles that were converted to shotgun use.