(set in 1930?, written in 1930, published in 1939)
Reason deserted me altogether, and before I knew what I was doing I drew my automatic and sent a shower of twelve steel-jacketed bullets through the shocking canvas. The whole thing at once fell to pieces, even the frame toppling from the easel and clattering to the dust-covered floor. But though this horror was shattered, another had risen before me in the form of de Russy himself, whose maddened shrieks as he saw the picture vanish were almost as terrible as the picture itself had been.
This description of the narrator’s pistol is rather more technical and specific about the type of gun than is usual for H.P. Lovecraft, who ghost-wrote this story for Zealia Bishop.
It was an “automatic,” meaning a semiautomatic pistol and not a revolver. At the time, many people were confused about the correct terminology. “Revolver” and “pistol” were often used interchangeably ‒ strictly speaking not wrong, as “pistol” really means “handgun,” but already inviting confusion because “pistol” started being used as short-hand for “semiautomatic pistol.” Many people used “revolver” interchangeably with “handgun” ‒ that is, also for semiautomatic pistols ‒, which is definitely wrong. “Automatic” was used almost universally for “semiautomatic pistol.” This is slightly imprecise, but not incorrect. The whole mess is compounded by contemporary revolvers that were branded “automatic” ‒ alluding to case ejection or safety mechanisms, not their action ‒, and of course by the coinage of the “automatic revolver,” of which very few real designs exist. Lovecraft is reasonably sure of this terminology throughout his oeuvre, including here.
It fired “steel-jacketed bullets,” not unjacketed lead bullets, which means it was not chambered for the .22 LR (5.6×16mmR) or a similar .22-calibre cartridge, since a metal-jacketed bullet in that calibre was not available until 1945. It probably used a more modern cartridge specifically designed for semiautomatic pistols, something like the .25 ACP (6.35×16mmSR Browning), 7.63×25mm Mauser, or .32 ACP (7.65×17mmSR Browning).
It had a capacity of at least 12 shots. This is a curiously exact number. Most semiautomatic pistols of the time have a capacity of 7-11 shots (6-10 in the magazine plus one in the chamber), some have considerable more (20 or even 22+1).
First, we have to consider the occasion. The narrator was travelling by motorcar through rural Missouri and then abandoned the automobile while seeking shelter for the night. Carrying a weapon on the road was actually quite common worldwide in the first half of the 20th century; as early as 1904, the German Fahrtenbuch für Automobilisten travel guide advised motorists to take a weapon along to counter the frequent attacks by pedestrians, especially in rural areas! The English Webley & Scott Revolver & Arms Co took out ads in 1906 to promote its .32-calibre automatic pistol (Investigator Weapons 1: The 1920s and 1930s, pp. 60-61) to drivers, while Colt’s ran a campaign in 1917 with the slogan: “Why not equip your car with a Colt?” The aptly-named Ithaca Auto & Burglar shotgun (Investigator Weapons 1, p. 79) was specifically produced between 1922 and 1934 to be carried in the car.
However, the narrator’s pistol is never mentioned until the very moment he drew and fired it. This suggests that he carried it unnoticed on his person the entire time. Carrying a pistol concealed imposes certain weight and size restrictions on the weapon, meaning a pocket pistol is far more likely than a long-barrelled target pistol or a military sidearm.
No pistol by a major manufacturer available in the timeframe has a 12-shot capacity. There are a few that come close:
The Colt Woodsman (Investigator Weapons 1, p. 44) has 11 (10+1) shots, but is chambered for the .22 LR, which I have already discounted. It is also rather large, being mainly intended for target shooting, with a long barrel, and therefore unlikely to be casually carried on one’s person.
The Mauser C96 (Investigator Weapons 1, pp. 48-50) has 10 shots; because of its unique loading procedure, no additional round can be chambered. It is famous for its powerful jacketed 7.63×25mm Mauser ammunition. However, in addition to being two shots short of the required 12, it is also a very large and bulky weapon unlikely to be carried concealed.
The Savage Model 1907 and the almost identical but less common Model 1917 (Investigator Weapons 1, pp. 55-56) have 11 (10+1) shots when chambered for the .32 ACP cartridge. In contrast to the other guns mentioned, this is a pocket pistol that was fairly widely sold in America at the time.
Then there are a few large weapons which have a higher capacity, including the 20-shot Astra Mod 902 in 7.63×25mm Mauser, 21-shot (20+1) Mauser C96 M1930 (Investigator Weapons 1, pp. 48-50) in 7.63×25mm Mauser, and 23-shot (22+1) Gabilondo Plus Ultra in .32 ACP. These could easily fire 12 shots and then stop. The two former are too large to carry concealed; the latter is not quite as bad, as it has a double-stack magazine, but is still heavy and not very concealable.
All in all, I would consider the Savage Model 1907 the most likely contender of the weapons mentioned, since it is both a compact pocket pistol that was commonly available in America at the time, and carries up to 11 shots. The discrepancy of the one missing shot could be chalked up as an honest mistake.
However, the kind of pistol that actually matches all three requirements is embodied by some of the many Spanish copies and developments of the Browning action that appeared in the 1920s, produced by a flourishing cottage industry in the Basque area around Eibar. There are several variations of these, with elongated grips for extended magazines. These include the 13-shot (12+1) Beistugei Royal, 13-shot (12+1) Echave y Arizmendi Pathfinder, and 13-shot (12+1) Gabilondo Danton War Model, all in .32 ACP. These pistols all look very similar, compact but with a rather long grip. The 13-shot (12+1) Astra Mod 700 Special in .32 ACP is made to look similar, but is actually based on the action of the Astra Mod 400 (Investigator Weapons 1, p. 36).
Similar pistols were made in Spain for the .25 ACP cartridge. These are of course smaller, but also less powerful. The 12-shot (11+1) Retolaza Model 1924 Liberty is typical.
All of them were primarily manufactured for export to Europe and Asia, but some also ended up in the USA, usually through distributors like Alexander Stoeger (Investigator Weapons 1, p. 25). Note that most of these are 13-shot weapons; however, in that day and age few people would carry their pistol “cocked and locked” with a round in the chamber, as manual safeties were not always to be trusted ‒ especially with the cheap Spanish designs, which retailed for around $10. Hugh Pollard writes of the latter in Automatic Pistols (1920) that “the only safe means to adopt is to refuse to have a Spanish pistol of any kind at any price.” With an empty chamber, all the narrator needed was to rack the slide while drawing it. And of course, this would give him exactly 12 shots.
And now comes the surprise. One of the many Spanish makers out of Eibar is the Manufactura de Armas Demon, which is possibly just a brand name used by another producer. One of their products was the 13-shot (12+1) Demon pistol in .32 ACP. This is marked as follows on the left side of the slide: “Automatic Pistol ‘Demon’ ‒ 32 Caliber Metal Covered Bullet.” In other words, it fits almost literally the description used by Lovecraft.
Lovecraft may have never seen or heard of the thing, but if someone were to replay the story or make a film out of it, a Demon pistol would be the ideal prop for the investigator.
Note that game-mechanically, a “shower” of 12 shots from a .32-calibre semiautomatic (ROF 3) takes at least four combat rounds ‒ 12-48 seconds (!) ‒, although we can probably assume them to be “Unaimed Shots” (Call of Cthulhu, Sixth Edition, p. 63), which doubles ROF and thus reduces this to two combat rounds. This kind of unaimed “panic fire” is no longer possible in Call of Cthulhu, Seventh Edition. Realistically, 12 shots can be easily fired in less than 3 seconds.