The 9x23 was made for the competition crowd, as a solution to feeding problems sometimes encountered with the semi-rim of the .38 super, especially in doublestack magazines. Also it's thicker, and better able to handle the pressures associated with "Major" power factor loads in USPSA matches.
The trouble was, by the time Winchester developed the cartridge, most shooters/pistolsmiths had figured out how to make the .38 super pistols run reliably. So, it never really took off. Typical to their nature, Colt came out with a 1911 chambered in 9x23 just as the cartridge started to tank.
On a personal note, I bought up a decent supply of factory 9x23 when a local store was going out of business. Occasionally I shoot some through one of my .38 super pistols (NOT the Ltwt. Commander btw), and it seems to work safely/reliably. However this practice is frowned on by some folks, who may well have a point. But that's a different topic.
The 9x21 was developed in Europe for shooters who aren't allowed to own handguns chambered in "military/LE only" calibers. (Nobody told these civilians that they couldn't have something chambered LONGER as opposed to shorter than a 9x19 gun.) I'm told the ballistics of the 9x21 are about identical to 9mm Parabellum.
The trouble was, by the time Winchester developed the cartridge, most shooters/pistolsmiths had figured out how to make the .38 super pistols run reliably. So, it never really took off. Typical to their nature, Colt came out with a 1911 chambered in 9x23 just as the cartridge started to tank.
On a personal note, I bought up a decent supply of factory 9x23 when a local store was going out of business. Occasionally I shoot some through one of my .38 super pistols (NOT the Ltwt. Commander btw), and it seems to work safely/reliably. However this practice is frowned on by some folks, who may well have a point. But that's a different topic.
The 9x21 was developed in Europe for shooters who aren't allowed to own handguns chambered in "military/LE only" calibers. (Nobody told these civilians that they couldn't have something chambered LONGER as opposed to shorter than a 9x19 gun.) I'm told the ballistics of the 9x21 are about identical to 9mm Parabellum.