e type Rimless, straight
Bullet diameter 0.451 in (11.5 mm)
Neck diameter 0.473 in (12.0 mm)
Base diameter 0.476 in (12.1 mm)
Rim diameter 0.48 in (12.2 mm)
Case length 0.898 in (22.8 mm)
Overall length 1.260 in (32.0 mm)
Case capacity 25 gr H2O (1.625 cm³)
Rifling twist 1 in 16 in (406 mm)
Primer type Large pistol
Maximum pressure 21,000 psi (140 MPa)
Ballistic performance
Bullet weight/type Velocity Energy
165 gr (10.7 g) Federal Premium Low Recoil JHP 1,060 ft/s (320 m/s) 412 ft·lbf (559 J)
185 gr (12.0 g) Corbon DPX 1,075 ft/s (328 m/s) 475 ft·lbf (644 J)
200 gr (13 g) Speer Gold Dot JHP +P 1,080 ft/s (330 m/s) 518 ft·lbf (702 J)
230 gr (15 g) Speer Lawman FMJ 830 ft/s (250 m/s) 352 ft·lbf (477 J)
Test barrel length: 5 in
Source: Midway USA[2]
The .45 ACP (11.43x23mm Automatic Colt Pistol), also known as the .45 Auto by C.I.P., is a rimless pistol cartridge designed by John Browning in 1904, for use in his prototype Colt semi-automatic .45 pistol and eventually the M1911 pistol adopted by the U.S. Army in 1911.
Contents [hide]
1 Design and history
2 Cartridge dimensions
3 Performance
4 Load variants
5 Timeline
6 Synonyms
7 Related rounds
8 References
9 External links
[edit] Design and history
The US Cavalry had been buying and testing various handguns in the late 1890s and early 1900s. The .45 Colt Single Action Army had largely been replaced, even by some double action versions of the same. The Cavalry had fielded some double action revolvers in .38 Long Colt, and they determined that the .38 caliber round was significantly less effective against determined opponents, such as those encountered in the Moro Rebellion warriors they were fighting at the time of the Philippine-American war, than the .45 Colt. The current issue rifle at the time, the .30-40 Krag, also had failed to stop Moro warriors;[3] the British had similar issues switching to the .303 British, which resulted in the development of the Dum-