9×23mm Steyr

For similarly dimensioned cartridges, see 9×23mm.

The 9×23mm Steyr, also known as 9mm Steyr, is a centerfire pistol cartridge originally developed for the Steyr M1912 pistol.

9×23mm Steyr
Type	Pistol
Place of origin	Austria-Hungary
Service history
Used by	Austro-Hungarian Army
Production history
Designer	Œ.W.G.
Produced	1911
Specifications
Case type	Rimless, straight
Bullet diameter	9.03 mm (0.356 in)
Neck diameter	9.62 mm (0.379 in)
Base diameter	9.70 mm (0.382 in)
Rim diameter	9.70 mm (0.382 in)
Rim thickness	1.25 mm (0.049 in)
Case length	23.20 mm (0.913 in)
Overall length	32.99 mm (1.299 in)
Primer type	Small pistol
Ballistic performance
Bullet mass/type Velocity Energy 115 gr (7 g) FMJ 1,025 ft/s (312 m/s) 268 ft⋅lbf (363 J) 115 gr (7 g) FMJ 1,080 ft/s (330 m/s) 298 ft⋅lbf (404 J) 115 gr (7 g) FMJ 1,230 ft/s (370 m/s) 388 ft⋅lbf (526 J)
Test barrel length: 128 mm (5.0 in) Source(s): 1. Hornady; 2. Fiocchi; 3. Hirtenberger

History

Adopted in 1912, the 9mm Steyr was the service ammunition for most branches of the military in Austria-Hungary during World War I and remained the service ammunition for Austria, Romania and Chile between the World Wars. Some MP 34 submachine guns were also issued in this caliber in addition to 9×25mm Mauser. When the Austrian Army was incorporated in the Wehrmacht in 1938 following the Anschluss, many Steyr M1912 pistols and MP 34 submachine guns were rebarrelled to 9×19mm Parabellum for standardization purposes.

Design

The cartridge headspaces on the mouth of the case. Its performance is close to that of the .38 ACP. Unrelated to the modern 9×23mm Winchester, it is similar to the 9×23mm Largo cartridge in performance, but their dimensions are just different enough to make them non-interchangeable.

Handloading

For handloading, reloadable Boxer-primed cartridge cases can be made from 5.56×45mm NATO brass. This requires inside neck-reaming, as such a conversion would otherwise leave unacceptably thick mid-to-rear case walls from the original cartridges to form the mouths of the new, shortened cases. At least one commercial source apparently can produce such a forming die set, complete with reamer. Loading data would be much like .38 ACP.

Gallery

• 
  Steyr M1912 pistol with holster and 9×23mm Steyr ammunition on stripper clips
• 
  Steyr M1912 pistol with box and stripper clip of 9×23mm Steyr ammunition
• 
  Left to right: 9×23mm Largo, 9×19mm Parabellum, 9×23mm Winchester, and 9×23mm Steyr