.32 ACP

.32 ACP (Automatic Colt Pistol), also known as the .32 Automatic is a centerfire pistol cartridge. It is a semi-rimmed, straight-walled cartridge developed by firearms designer John Browning, initially for use in the FN M1900 semi-automatic pistol. It was introduced in 1899 by Fabrique Nationale, and is also known as the 7.65×17mm Browning SR or 7.65 mm Browning.

History
John Browning engineered a number of modern semi-automatic pistol mechanisms and cartridges. As his first pistol cartridge, the .32 ACP needed a straight wall for reliable blowback operation as well as a small rim for reliable feeding from a box magazine. The cartridge headspaces on the rim. The cartridge was a success and was adopted by dozens of countries and countless governmental agencies.

When the .32 ACP cartridge was introduced, it was chambered in a variety of popular blowback automatic pistols of the day, including the Colt Model 1903 Pocket Hammerless, the Savage Model 1907 Automatic Pistol, and the Browning Model 1910 Automatic Pistol. The .32 ACP has been chambered in more handguns than any other cartridge. Between 1899 and 1909, Fabrique Nationale produced 500,000 guns chambered for .32 ACP.

Adolf Hitler was believed to have committed suicide with his personal .32 ACP Walther PPK, by pressing it against his right temple and pulling the trigger while simultaneously biting down on a cyanide capsule.

The popularity of the .32 ACP in the mid 20th century cannot be overstated—especially in Europe. Firearms expert Geoffrey Boothroyd of the UK informed author Ian Fleming, his countryman, that James Bond's side arm should be a Walther PPK chambered in .32 ACP. A significant factor in recommending this round was its near universal availability throughout the world in the 1950s.

Heckler & Koch produced the HK 4, their first handgun, in 1967. Twelve thousand HK 4 pistols were produced in .32 ACP for the German police and other government agencies.

Design
The .32 ACP was designed for blowback semi-automatic pistols which lacked a breech locking mechanism. The relatively low power and light bullet of the cartridge allowed Browning to incorporate a practical blowback mechanism in a small pocket-size pistol. It is still used today primarily in compact, inexpensive pistols. Cartridges in .32 ACP are also sometimes used in caliber conversion sleeves, also known as supplemental chambers, for providing an alternative pistol caliber carbine function in .30-caliber hunting rifles.

Performance
The .32 ACP is compact and light. While some believe it has marginal stopping power, it has been used effectively by military and police worldwide for the past century. Weapons chambered in it are often valued for their compactness. Although .32 ACP handguns were traditionally made of steel, they have been produced in light weight polymers since the 1990s. Their light weight relative to larger caliber pistols make them sutiable for concealed carry use.

It offers more velocity and energy than the .32 S&W, which was a popular round for pocket defensive revolvers at the time of the .32 ACP's development. Although of lighter bullet weight, the .32 ACP also compares favorably to the .32 S&W Long in performance. Some European 73 grain .32 ACP loads provides similar performance to the .32 H&R Magnum 77 grain lead flat point and 90 grain lead semiwadcutter.

Even though the .32 ACP is capable of killing small game, most handguns chambered for this round utilize fixed sights and are designed for use against human-sized targets at fairly close range, which greatly limits their utility as hunting handguns.

The .32 ACP is one of the most common calibers used in veterinary "humane killers", such as the Greener Humane Killer. Given that a .22 LR can penetrate bone, the higher power .32 ACP can easily penetrate an animal skull with a muzzle-contact shot. As a result the round has been found to be perfectly adequate for the purpose, even where fully grown horses and bulls are concerned.

In Europe, where the round is commonly known as the 7.65 mm Browning, the .32 ACP has always been more widely accepted than it has in America, having a long history of use by civilians and police/security forces, along with limited issue by the military forces of some European nations.

During the second half of the 20th century, several European countries developed firearms for police chambered in 9x18mm Makarov while chambering the same pistol for civilians in .32 ACP and .380 ACP. Examples include the Vz. 82/CZ-83 from Czechoslovakia, FEG PA-63/AP 765 from Hungary, SIG Sauer P230 from Switzerland, and P-83 Wanad from Poland.

Today the cartridge has an increased popularity in the United Sates due to modern compact concealed carry pistols chambered for it, such as the Kel-Tec P-32, Beretta Tomcat, Seecamp LWS 32 and North American Arms Guardian .32. This increase in popularity has led many ammunition manufacturers to develop new loads for the cartridge to increase performance.

However, these polymer subcompact guns typically have barrel lengths around 2.5". The traditional steel guns chambered for .32 ACP have barrel lengths around 3.5". Different barrel lengths can have a significant effect on bullet performance with longer barrels providing higher muzzle velocity and energy. For example, a Cor-Bon 60 grain .32 ACP JHP has 130 ft•lbf of energy when fired out of a 2.5" barrel and 165 ft•lbf of energy when fired out of a 3.5" barrel. The shorter barrel length can also reduce the accuracy and range of a bullet.

Synonyms

 * 32 Auto (typical designation in America)
 * 7.65 mm Browning (typical designation in Europe)
 * 32 Browning Auto
 * 7.65×17mm
 * 7.65×17mm Browning SR (SR = Semi-Rimmed)
 * 7.65 Walther

Prominent firearms chambered in .32 ACP

 * Beretta M1935
 * Beretta Model 70
 * Beretta Model 81 and 82
 * Beretta 3032 Tomcat
 * Colt Model 1903 Pocket Hammerless
 * CZ-50
 * CZ-70
 * CZ-83
 * ČZ vz. 27
 * FÉG 37M Pistol
 * FÉG AP 765 Pistol
 * FN M1900
 * FN Model 1910 and 1910/22
 * Heckler & Koch HK 4 P11
 * Kel-Tec P-32
 * Llama Bufalo/Danton/Llama I/Llama X-A
 * MAB Model D
 * Mauser HSc
 * Mauser Model 1934
 * Radom P-83 Wanad
 * Remington 51
 * Ruby
 * Sauer 38H
 * Savage Model 1907
 * Seecamp LWS 32
 * SIG Sauer P230
 * Škorpion vz. 61 Machine pistol
 * Smith & Wesson Model 35
 * Walther PP
 * Walther PPK
 * Webley & Scott M1905-M1908
 * Welrod
 * Zastava M70