9x23 mm & .357 Sig

by
posted on October 31, 2013
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
9x23mmWinchester_f.jpg

I watched Sheriff Jim Wilson fire the first round of 9x23 mm JHP ammo into a defenseless block of ordnance gelatin. It was at a writer’s seminar where the gun and cartridge were introduced to the shooting world. Jim may also have been present when another maker brought out its version of ammo for the .357 Sig cartridge. I can’t recall what the good sheriff had to say about these two rounds, but I’ll bet that he has observed the same thing that I have-one made it, one didn’t.

Both calibers were intended to bump up the ballistic performance level of mid-bore pistol cartridges. The 9x23 mm was a .45 ACP-length round intended for single-column M1911-style pistols. Approximately the same length as the .38 Super, the 9x23 was essentially a lengthened 9 mm Luger cartridge. Actually, it had another characteristic that was new to auto pistol design. In order to better handle the higher pressure that would make this so-called “long nine” perform, the case head was deliberately thickened. This gave the base of this cartridge greater mass and strength. It was an approach once tried in Jeff Cooper’s early SWPL days. Initial offerings in 1996 were Colt 1911 pistols, which fired the round with accuracy and power. Colt and Winchester Ammunition wanted a gun for the IPSC circuit.

In 1994, SIG collaborated with Federal to develop the .357 Sig cartridge. This redoubtable Swiss-German-American firm wanted a powerful medium-bore automatic pistol round that was short enough to comfortably fit in the double-wide magazines of.40 S&W-sized autos. They weren’t going after the gamesmen, but rather the warriors. Working from the already successful .40 S&W case, they necked it down to take 9 mm (not .357 inch) bullets of medium weight. It was a resounding success, achieving velocities in the mid 1,300 fps range. The forgoing description admittedly oversimplifies the cartridge development just a bit. The .357 Sig cartridge works in 9 mm-size pistols, where the bottlenecked case spells ultra-reliable feeding. The cartridge simply works.

Comparing the two is something of an apples-and-oranges thing in the sense that they were really intended for different roles. Whatever the intent, the fact is the 9x23 flopped and is now almost forgotten. And while it is used by a number of prestigious police agencies, the .357 Sig does not enjoy the wide success its designer/developers were seeking.

Latest

Magpul Hunter Lite Stock
Magpul Hunter Lite Stock

New for 2026: New Products from Magpul

Magpul announces new metal-magazines, new stocks and pistol frames.

New for 2026: Burris Veracity Riflescopes

The latest generation of Veracity scopes is available in a variety of 5X magnification ranges.

New for 2026: Springfield Armory 10-8 Performance Master Class 1911 Pistols

Springfield Armory and Lipseys have partnered to offer a highly custom 1911 with input from Hilton Yam.

New For 2026: Diamondback SDR-A

Following the release of its Self-Defense Revolver in 2024, Diamondback Firearms has now lightened its design and reduced the cost with the new-for-2026 SDR-A.

Rifleman Review: Walther Arms PDP F-Series 4-Inch

Walther Arms continues to expand its F-Series handgun line, a design initially developed for women but that has broad appeal across the firearm consumer market, thanks to its unique design elements and feature set.

Mossberg Expands Budget-Priced Maverick Line With Semi-Auto Model

As part of its International family of shotguns, Mossberg announced the introduction of the Maverick SA Semi-Auto, a versatile, value-focused semi-automatic platform built to deliver reliable performance.

Interests



Get the best of American Rifleman delivered to your inbox.