Buy 45 ACP Online Australia

Introduction

The 45 ACP (Automatic Colt Pistol), also known as 45 Auto, .45 Automatic, or 11.43×23mm is a rimless straight-walled handgun cartridge designed by John Moses Browning in 1904, for use in his prototype Colt semi-automatic pistol. After successful military trials, it was adopted as the standard chambering for Colt’s M1911 pistol. The round was developed due to a lack of stopping power experienced in the Moro Rebellion in places like Sulu. The issued ammunition, a .38 Long Colt, had proved inadequate, motivating the search for a better cartridge. This experience and the Thompson–LaGarde Tests of 1904 led the Army and the Cavalry to decide that a minimum of .45 caliber was required in a new handgun cartridge.

The standard issue military .45 ACP round uses a 230-grain (14.9 g) round nose projectile that travels at approximately 830 feet per second (250 m/s) when fired from a government-issue M1911A1 pistol. It operates at a relatively low maximum chamber pressure rating of 21,000 psi (140 MPa), compared to 35,000 psi (240 MPa) for both 9mm Parabellum and .40 S&W, which due to a low bolt thrust helps extend the service lives of weapons. Since standard-pressure .45 ACP rounds are subsonic when fired from handguns and submachine guns, it is a useful caliber for suppressed weapons to eliminate the sonic boom.

During the late 19th century and early 20th centuries, the U.S. Cavalry began trials to replace their sidearm arsenal of issued .45 Colt Single Action Army (SAA) in favor of the more modern and versatile double-action revolver with .45 Colt.

After the example of the Cavalry, the Army in turn had fielded versions of double-action revolvers in .38 Long Colt. It was eventually evaluated that the .38 caliber round was significantly less effective in overall stopping power than the .45 Colt against determined opponents in cases such as the Tausug Moro juramentado warriors, who were encountered in the Moro Rebellion. The standard-issue rifle, the .30-40 Krag, had also failed to stop Moro warriors effectively; the British had similar lack-of-stopping-power issues switching to the .303 British, which resulted in the development of the dum-dum bullet, in an attempt to compensate for the round’s deficiencies. This experience, and the Thompson–LaGarde Tests of 1904, led the Army and the Cavalry to decide a minimum of .45 caliber was required in a new handgun. Thompson and Major Louis Anatole La Garde of the medical corps arranged tests on cadavers and animals in the Chicago stockyards, resulting in their declaring that the .45 was the most effective pistol cartridge. They noted, however, that training was critical to make sure a soldier could score a hit in a vulnerable part of the body.

Colt had been working with Browning on a .41 caliber cartridge in 1904, and in 1905, when the Cavalry asked for a .45 caliber equivalent, Colt modified the pistol design to fire an enlarged version of the prototype .41 round. The result from Colt was the Model 1905 and the new.45 ACP cartridge. The original round that passed the testing fired a 200-grain (13 g) bullet at 900 ft/s (274 m/s), but after a number of rounds of revisions between Winchester Repeating Arms, Frankford Arsenal, and Union Metallic Cartridge, it ended up using a 230-grain (15 g) bullet fired at a nominal velocity of 850 ft/s (259 m/s). The resulting .45 caliber cartridge, named the “.45 ACP”, was similar in performance to the .45 Schofield cartridge and only slightly less powerful while significantly shorter than the .45 Colt cartridge that the United States Cavalry was using at the time.

By 1906, bids from six makers were submitted, among them, Browning’s design, submitted by Colt. Only DWM, Savage, and Colt made the first cut. DWM, which submitted two Luger pistols chambered in .45 ACP, withdrew from testing after the first round of tests, for unspecified reasons.

During the second round of evaluations in 1910, the Colt design passed extensive testing with no failures, while the Savage design suffered 37 stoppages or parts failures. The Colt pistol was adopted as the Model 1911.

The cartridge-pistol combination was quite successful but not satisfactory for U.S. military purposes. Over time, a series of improved designs were offered, culminating in the adoption in 1911 of the “Cal. 45 Automatic Pistol Ball Cartridge, Model of 1911”, a 1.273-inch-long (32 mm) round with a bullet weight of 230 grains (15 g). The first production, at Frankford Arsenal, was marked “F A 8 11”, for the August 1911 date.

The cartridge was designed by John Browning for Colt, but the most influential person in selecting the cartridge was Army Ordnance member General John T. Thompson. After the poor performance of the Army’s .38 Long Colt pistols evidenced during the Philippine–American War (1899–1902), Thompson insisted on a more capable pistol cartridge.

The .45 ACP is an effective combat pistol cartridge. It combines accuracy as well as stopping power for use against human targets, has relatively low muzzle blast and flash, and produces a stout, but manageable recoil in handguns (made worse in compact models). The .45 ACP is generally considered to have greater stopping power than the 9mm. Due to its larger size and slower velocity, it creates a larger wound channel and transfers more energy to the target.

The standard-issue, military .45 ACP cartridge contains a 230-grain bullet that travels at approximately 830 feet per second (253 m/s) when fired from the government-issue M1911A1 pistol, and approximately 950 feet per second (290 m/s) fired from the Thompson M1A1 submachine gun. The cartridge comes in various specialty rounds of varying weights and performance levels as well.

The cartridge operates at a relatively low maximum chamber pressure rating of 21,000 psi (145 MPa) (compared to 35,000 psi [241 MPa] for 9mm Parabellum and .40 S&W, 37,500 psi [259 MPa] for 10mm Auto, 40,000 psi [276 MPa] for .357 SIG), which due to a low bolt thrust helps extend service life of weapons in which it is used. Some makers of pistols chambered in .45 ACP, do not certify them to use +P ammunition.

In its non-expanding full metal jacket (FMJ) version, the .45 ACP cartridge has a reputation for effectiveness against human targets because of its heavy mass, having the capacity to penetrate tissue deeply and damage the central nervous system. Its large 11.5 mm diameter creates a more substantial permanent wound channel versus smaller calibers, which can lower blood pressure rapidly if critical organs of the circulatory system are hit.

In its expanding hollow point form, it is also particularly effective against human targets. In tests against ballistic gelatin, a 185-grain hollow point traveled at 1,050 feet per second and expanded to about .76 of an inch. This is a significantly large permanent wound cavity for a handgun projectile. For those who follow the energy dump and/or hydrostatic shock theories of wounding ballistics, this is ideal. While slightly decreasing penetration and likewise the chance of hitting a vital organ, a large diameter wound will cause more blood loss. There is also a reduced likelihood of overpenetration, meaning that it is more likely that the projectile will transfer all of its kinetic energy to the intended target, thus more reliably incapacitating it.

Drawbacks for military use include the cartridge’s large size, weight, and increased material costs in comparison to the smaller, flatter shooting NATO standard 9×19mm Parabellum cartridge, a cartridge that uses less powder, brass, and lead per round. Standard 9mm NATO ammunition has a more limited armor penetration capability—a deficiency shared with .45 ACP, whose large, slow bullet does not penetrate armor to any great extent. The low muzzle velocity also makes the bullet drop over long ranges, making hits more difficult; however, it is important to note that the vast majority of self-defense situations involving handguns typically occur at close ranges.

After two years of testing, one of the final FBI comments was that services that adopt (or stay with) .40 S&W or .45 ACP, did so at the risk of increased recoil and a possible reduction in accuracy as 9×19mm with premium quality ammunition had nearly exactly the same performance. A factor rated by the recent FBI testing was accuracy and time to recover. The .45 ACP handguns ranked last, largely due to increased recoil. Magazine capacity varies depending on the type of firearm. Standard (not extended) single-stack magazines for pistols based on the 1911 design commonly, hold eight rounds or fewer in .45 ACP. Many modern pistols have adapted the cartridge into double-stacked magazine designs to increase ammo capacity, though this increases the pistol grip’s girth. Drum magazines used mostly for submachine guns have a capacity of 50 or 100 rounds.