The 9×23 Winchester is a pistol cartridge developed as a joint venture by Winchester Ammunition and Colt’s Manufacturing Company. 9x23mm has a convoluted development history, but was commercially introduced by Winchester in 1996. Marketed primarily to competition shooters as a replacement for .38 Super for International Practical Shooting Confederation, United States Practical Shooting Association and International Defensive Pistol Associationcompetition, the cartridge made a splash, but never really caught on.

The main advantage of 9x23mm Winchester is a much strengthened case that does away with the semi-rimmed casedesign of the .38 Super. The strengthened case allows the 9x23mm Winchester to operate under a higher internal pressure, 40,000 CUP, than the .38 Super which maxes out around 30,000 CUP. Also, the case is not necked down like the .357 SIG, 9x25mm Super Auto G, or 9x25mm Dillon allowing greater magazine capacity; however the 9×23 is longer overall thus requiring the extra length of a 1911 style magazine.

 

History

Patent 5,187,324 was filed by John Ricco of CP Bullets in 1992 for an “improved 9mm cartridge casing” that he called the 9×23 Super. He had the brass casing made by Winchester Ammunition which they took, improved upon, and filed patent 5,507,232 in 1995. Winchester had lengthened the overall case by 4mm and removed the semi-rim of the case and named their new cartridge the 9×23mm Winchester. Ricco sued for the royalties that Winchester denied him and won.

Announced to the public in early 1996 at an NRA convention, the 9×23mm Winchester cartridge was designed to have the lowest recoiling load and still qualify for Major Power Factor designation in the IPSC. IPSC Power Factor (PF) is equal to bullet weight in grains times muzzle velocity with a PF of at least 175 equaling a Major Power Factor designation. A lighter bullet weight requires a larger muzzle velocity to achieve the same PF and the larger charge of powder required to achieve this velocity creates higher pressure inside the case.

Winchester designed the 9×23mm to prevent case-wall blowout caused by the increased pressure by thickening the web section, which is the “solid” part of the case.

The event that spelled doom for the cartridges like the 9×23mm Winchester and 9×25mm Dillon in competition use was when USPSA reduced the power factor necessary to make Major, from 175 to 165. This greatly reduced the internal pressures required allowing ammunition with less charge to qualify for Major Power Factor.

Effects

ReloadingThe performance of the 9x23mm Winchester is virtually identical to that of the .357 SIG.(These figures exceed the factory ballistics of a .357 SIG in a 4″ test barrel. Even using a 5″ bbl. it is not likely that you would hit 1,450fps with a 125gr bullet in the .357 SIG. Not while staying within SAAMI pressure limits.) Being that it is a long form pistol round, it fits large frame automatics such as the 1911. Not being suitable for small(er) frame pistols chambered for rounds like 9x19mm Parabellum, it never gained the mainstream recognition the .357 SIG enjoys, despite offering similar ballistics and terminal effects as well as higher magazine capacity.

The maximum over all length of the cartridge can vary with the magazine length of the converted pistol. A Star Super B converted to 9x23mm may be loaded to 1.29″ while a converted Tokarev may be loaded to 1.36″. Using this cartridge at full power in a handgun built around the standard .38 Super ACP +P pressure limits and lower may result in a drastically increased level of wear on the firearm or even serious damage to it due to insufficient tensile strength+hardening of the frame, slide and various small parts