At 25 meters, the 10mm bullet [180] is travelling faster than a .45 round at the muzzle. Velocity is not the whole story, of course, but the 10mm is certainly an interesting development, and like the .45 ACP, as nicely usable in revolvers as in semiautos.
Among its shortcomings is that it can be brutal to machinery adapted to it rather than purpose-designed for it, as per the Colt Delta Ten. But it's interesting too for it's usability in handgun-carbine or handgun-SMG combinations.
And back when the Norma factory loadings appeared, I ran across a AKM kalishnikov adapted to the 10mm cartridge, interesting but I'm not certain as to the exact requirements the user had in mind for the one-off custom work, with a very nice Lothar Walther target barrel pretty much wasted in an AKM action. But the 7,62x39mm AK cartridge necked out to 10mm also has interesting possibilities....
-archy-/-
Are they still in use? Have they had problems?
Squantos mentioned he heard about some teething problems, some bad mags and cracked mag well, if I remember correctly.