Munitions

45 Automatic (45 Auto)

Also known as
  • 45 Auto
  • .45 Auto
  • 45 ACP
  • .45 ACP
  • 45 Automatic Colt Pistol

45 Automatic (45 Auto) is SAAMI's recognized name for the classic U.S. centerfire pistol cartridge chambered by the Glock 21 family. SAAMI publishes the standardized 45 Auto / 45 Auto +P drawing and pressure standard, while Federal Premium, Remington, and Winchester still sell current commercial loads.

Profile / Specs

Profile

Origin
United States
Type
SAAMI-recognized pistol cartridge
Service note
Early 20th century to present
Designer
John Moses Browning / Colt
Designed
1904-1911
Unit cost
$38.99 per 50-round box of American Eagle Handgun, 45 Auto, 230 Grain, Full Metal Jacket, 890 fps
Produced
1911-present

Specifications

SAAMI name
45 Automatic (45 Auto)
SAAMI MAP
21,000 psi
Case length
0.898 in (22.81 mm)
Overall length
1.190-1.275 in (30.23-32.39 mm)
Bullet diameter
.4520 in (11.481 mm)
Representative load
230-grain FMJ, 890 fps
Variants
  • 45 Automatic +P
  • 45 Automatic Match
Compatible Firearms

SAAMI recognizes 45 Automatic as the correct cartridge name, and GLOCK lists the G21 Gen4 as chambered in .45 Auto.

Compatible itemItem typeCompatibility evidence
Glock 21, .45 Auto semi-automatic pistol, Infantry WeaponsGlock 21Semi-automatic pistol

GLOCK identifies the G21 Gen4 as chambered in .45 Auto, which is the same cartridge SAAMI recognizes as 45 Automatic (45 Auto).

Sources: SAAMI FAQs, GLOCK 21 Gen4

Service And Conflict Use

Service History

In service
Commercial centerfire pistol cartridge standardized by SAAMI as 45 Automatic (45 Auto).
Media
Related Weapon Systems

Sources