I have a S&W Model 58. Great wheelgun, love it to death. Will never sell or trade it.
That said, until the .41 Special came along, all .41 mag revolvers were just one cartridge guns.
If converted to 10mm Magnum, a 10mm revolver instantly becomes a versatile 3-in-1 gun. All three cartridges - 10mm Mag, 10mm, & .40S&W - can be loaded and fired using the same 10mm moon clips. But that's the versatility benefit ...
If you study John Taffin's early research and reloading work on the 10mm Magnum, when he was testing the cartridge with IAI's
semi-auto pistol, the Auto Mag IV, you'll see the 10mm Mag actually yields slightly better ballistics than the .41 Mag with similar bullet-weights.
And that was in an
autoloader where COAL is restricted for reasons of magazine fit as well as chambering. In a revolver, you have a bit more leeway to 'long-load' the bullets, so you can actually achieve more velocity with less pressure.
Many S&W 610 owners were doing just that with the 10mm AUTO cartridge which ordinarily has a max COAL of 1.260 in semi-autos. In the 610 revolver, users have posted about long-loading their 10mm rounds to 1.300, 1.350, and longer COALs in order to increase the powder charge under the bullet without ramping up the pressure.
Taffin concludes:
More here:
http://www.sixguns.com/tests/tt10mag.htm