A machine pistol is a handgun that is capable of fully automatic fire, including stockless handgun-style submachine guns.
During World War II, machine pistol development was widely disregarded in favor of submachine gun mass-production.
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.
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).
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.
[4] In 1916, Heinrich Senn of Bern designed a modification of the Swiss Luger pistol to fire in single shots or in full-automatic.
During World War II, machine pistol development was more or less ignored as the major powers were focused on mass-producing submachine guns.
Like the other common Russian army pistol of this era, the Makarov, the Stechkin uses a simple unlocked blowback mechanism and the double action trigger.
What makes the Stechkin APS a machine pistol is that it has an automatic fire mode, which is selected using the safety lever.
The Stechkin was intended as a sidearm for artillery soldiers and tank crews, but in practice, it ended up earning a strong following in the ranks of political and criminal police forces.
The Skorpion's lower-powered .32 ACP cartridge, coupled with a rate-of-fire limiting device housed in the grip (which allows a reasonable rate of 850 RPM with a relatively light bolt), also makes it easier to control in full-auto than the more common 9 mm Parabellum designs.
The weapons were used in special operations and covert applications in Vietnam and by Brazilian anti-terrorist units, most people fitting it with a silencer using its threaded barrel.
In 1976, a shortened version of the 9 mm Parabellum Heckler & Koch MP5 was introduced; the MP5K (K from the German Kurz = "short") was designed for close quarters battle use by clandestine operations and special services.
It offered extra firepower in a smaller package and is suited for concealed carry purposes such as VIP protection, or for close quarters maneuvers such as room-to-room searches.
A selector switch and the foldable foregrip allow the pistol to fire three-round bursts with each trigger pull for a cyclic rate of 1100 rounds per minute.
[7] The Stechkin APS made a comeback in the late 1970s when Russian Spetsnaz special forces units in Afghanistan used the suppressor-equipped APB variant for clandestine missions in enemy territory, such as during the Soviet–Afghan War.
This machine pistol has a horizontal rail in front of the trigger guard through which a spare 16- or 20-round magazine can be attached and be used as a fore-grip for better control during full automatic firing.
During the 1990s, the Russian Stechkin APS was once again put into service, as a weapon for VIP bodyguards and for anti-terrorist hostage rescue teams that needed the capability for full automatic fire in emergencies.
The Beretta 93R not only uses a detachable shoulder stock and a three-round-burst limiter, but also a folding forward hand-grip to improve controllability in full auto.
[citation needed] Gunsite, a US firearms training facility, decided against teaching machine pistol firing when it was founded in 1976.
[citation needed] In the 1970s, International Association of Chiefs of Police weapons researcher David Steele criticized the MAC-10's accuracy when he hyperbolically described the MAC series as "fit only for combat in a phone booth".
[12] Leroy Thompson states that "...machine pistols were reasonably good for use from within a vehicle or for issue to VIP [bodyguard] drivers to give them a marginally more effective weapon during an evacuation under fire".