Machine pistol

A machine pistol is a handgun that is capable of fully automatic fire, including stockless handgun-style submachine guns.

The Austrians introduced the world's first machine pistol, the Steyr Repetierpistole M1912/P16, during World War I. The Germans also experimented with machine pistols, by converting various types of semi-automatic pistols to full-auto, leading to the development of the first practical submachine guns. During World War II, machine pistol development was widely disregarded in favor of submachine gun mass-production. After the war, machine pistol development was limited and only a handful of manufacturers would develop new designs, with varying degrees of success. This concept would eventually lead to the development of the personal defense weapon or PDW.

Today, machine pistols are considered special-purpose weapons with limited utility, with their original niche being filled with either the PDW, carbines, or simply more modern semi-automatic sidearms. Contributing to their already-fringe use, without a shoulder stock and training, machine pistols can be difficult to control for all but the best shooters.

In 1896 a select-fire pistol was patented by the British inventor Hugh Gabbett-Fairfax.

During World War I, a machine pistol version of the Steyr M1912 called the Repetierpistole M1912/P16 was produced. It used a 16-round fixed magazine loaded via 8 round stripper clips, a detachable shoulder stock and a rather large exposed semi-auto/full-auto selector switch on the right side of the frame above the trigger (down = semi & up = full). It fired the 9×23mm Steyr cartridge, with a full-auto rate-of-fire of about 800 to 1,000 rounds per minute (RPM). It weighed about 2.6 pounds. Introduced in 1916, it is considered one of the world's first full-auto capable pistols. Only 960 M1912/P16 were made.

An automatic version of the Frommer Stop pistol was also tested, including a variant known as the Doppelpistole where two guns were joined together and mounted upside down on a tripod.

In 1916, Heinrich Senn of Bern designed a modification of the Swiss Luger pistol to fire in single shots or in full-automatic. Around the same time Georg Luger demonstrated a similar Luger machine-pistol which inspired the German Army to develop submachine guns.

The Mauser C96 was introduced in 1896, it being one of the first commercially successful and practical semi-automatic pistols. During World War I, the Germans experimented with machine pistols by converting both 7.63mm Mauser and 9 mm Parabellum semi-automatic C96 pistols to full-auto. In the late 1920s, Spanish gunmakers expanded upon this idea by introducing select fire copies of the C96 with 20-round detachable magazines. In the early 1930s, Mauser engineers finally followed suit, and introduced the Model 1932 or Model 712 Schnellfeuer variant, which also included 20 round detachable magazines and a select fire mechanism allowing for fully automatic fire at a rate of 1,000 RPM.