There are handguns. There are submachineguns. And in between those two classifications there is a type of gun that is half handgun and half submachinegun: the machine pistol.
The machine pistol was born early in the 20th century. The concept usually started with a self-loading (semi-automatic) pistol that was converted to fire bursts or full auto. Often, provisions were made to increase the ammunition capacity. The ability to add a shoulder stock or some other method of stabilizing the machine pistol was also common.
In theory, it’s a great concept: maximum firepower in minimum size. (click the title for more)
Steyr made a fully-automatic version of their M1912 service pistol. Since this was a fixed-magazine design fed by stripper clips, the built-in magazine was extended to provide more ammunition capacity. Not ideal, but it apparently worked to some degree.
Another early example was the Mauser C96 “Broomhandle”. The provision for a shoulder stock made the Mauser a natural choice to convert to full-auto. But it was 2 Spanish companies that first built full-auto versions of the Broomhandle in the late 1920s. They also converted the design to use a 20-round detachable magazine. Mauser developed their own version in 1930, called the M1932 (or M712 in WW2 service).
Beretta adapted their M1951 9mm pistol to full-auto and added a folding front grip and a 10-round (instead of eight) magazine. The result was the M951R. It was not very successful, due to low ammo capacity and controllability issues, but it led to the later, more successful designs (see below).
Heckler & Koch debuted their version of a machine pistol in 1970, the VP70. The military version (VP70M) could fire 3-round bursts (at a cyclic rate of 2200 rounds-per-minute!) when the shoulder stock was attached (which might disqualify it from being a true “machine pistol”). The 18-round magazine gave enough capacity to make this a potentially useful feature, and the very high cyclic rate made the bursts controllable. I have heard different stories about the trigger: most say it is a long heavy trigger but a few have described it as OK. Despite being a very viable design on paper, the VP70M has not seen widespread use.
Beretta took the lessons they learned with the M951R and created a new, refined machine pistol out of their full-size Model 92 pistol: the Beretta 93R. They added a longer, compensated barrel and a 20-round magazine. The stock is optional; the 93R will fire 3-round bursts with or without the stock attached. The upward-folding, angled forward grip for the weak hand adds to controllability (notice the longer trigger-guard; the weak hand’s thumb goes through the trigger guard while the fingers wrap around the angled grip to prevent your weak hand from ending up in front of the barrel).
The Soviets made a machine pistol using the Makarov (9x18mm) cartridge, called the Stechkin APS. It sort of looks like a Makarov on steroids, and should have the stock attached to fire in full auto mode.
CZ created a full-auto version of the CZ75 pistol. Rather than add a handgrip, they provided an attachment point to connect a spare magazine to serve as a grip. I wonder how wise it is to leave the feed lips of a magazine exposed to potential damage.
And then we come to the holy grail of machine pistols: the Glock 18. No bursts here; full-auto capability, with standard or compensated versions available. No stock needed, it will rock and roll right from a standard holster. Uses the standard 17-round or optional 33-round magazines (yes, the ones made famous by loony Jared Loughner).
Despite the many designs of machine pistols, this type of weapon has never enjoyed widespread success. They are not as accurate/controllable as a traditional submachinegun, and they require a much higher level of training to safely employ. Most militaries and police forces find that their training time/money are better spent on a traditional submachinegun or a PDW. Bodyguards are a common employer of machine pistols; the need to maintain a discreet appearance is paramount, and the machine pistol enables a more intimidating weapon than a pistol to be effectively concealed. I wonder how effectively they can be employed one-handed, since their other hand might be occupied shepherding their “principal”. Collateral damage would be a concern.
All things considered, I believe the Beretta 93R is the best option in this class of weapons. No stock needed (so it can be concealed), bursts (rather than full-auto) to keep it controllable, and a pretty good system for letting the weak hand get a solid grip on the gun. I am sure that you could attach a foregrip to the rail on the front of the Glock 18, which would make it easier to control. But you might lose concealability/holsterability.
Yes, there are some very small submachineguns. The H&K MP5K, Ingram MAC-10/11, Micro Uzi and Vz61 Skorpion for example. While small, they started life as submachineguns, not pistols. And most are not “holsterable”.
That’s the story on machine pistols.
UPDATE: Rob over at The Truth About Guns has pointed out that there have been full-auto conversions of 1911s, including one allegedly used by John Dillinger.