The .41 Magnum is a wonderful performer, but it was a huge mistake in one aspect from a marketing and practicality stand point.

That would be bullet diameter. It is simply too close to the .44 Magnum in size (.410 vs .429). It should have been a true .40 caliber Magnum from the start.

A six shot .40 Caliber Magnum in a medium frame/L frame sized revolver would have gone over much better. That would have also given the .357 Magnum a much better home 16 years before the L frame finally did show up. A six shot .41 Magnum is confined to an N frame sized revolver, and most folks (then and now) do not see why you should spend the extra coin, when you can get a six shot .44 Magnum on the same frame size.

The .401 Powermag is the cartridge that the industry should have gotten behind.