Colt M16A1
Colt's Manufacturing Company · Assault Rifle · Out Of Production · 1967
Also known as: Rifle, 5.56mm, M16A1, Colt Model 603
Overview
The Colt M16A1 was the improved standard-issue model of the M16 family adopted by the U.S. Army in 1967, derived directly from the XM16E1. Its defining change over the original M16 was the addition of the forward assist plunger, allowing a soldier to manually seat the bolt. Later M16A1 production added a chrome-lined chamber and bore to address the fouling and corrosion problems that plagued early rifles in Vietnam. It became the iconic American infantry rifle of the Vietnam War.
Specifications
| Weight (empty) | 3180 g (112.2 oz) |
| Weight (loaded) | 3900 g (137.6 oz) |
| Overall Length | 986 mm (38.82") |
| Barrel Length | 508 mm (20.00") |
| Sight Radius | 500 mm (19.69") |
| Action Type | Gas Operated Direct Impingement |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Magazine Capacity | 20 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 975 m/s (3199 fps) |
| Muzzle Energy | 1693 J (1249 ft·lbf) |
| Effective Range | 400 m (437 yd) |
| Maximum Range | 2653 m (2901 yd) |
| Rate of Fire | 750 rpm |
| Barrel Rifling | Right Hand |
| Rifling Twist | 305 mm (12.01") |
| Number of Grooves | 6 |
| Frame Material | Aluminum |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Anodized |
Calibers
- 5.56x45mm NATO · primary · 5.56mm NATO — also known as 5.56x45mm, 5.56 NATO, 5.56x45mm M193
Features
- Firing modes: Semi Automatic, Full Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety, Selector Lever
- Features: Forward Assist, Fixed Carry Handle, Chrome Lined Chamber, Birdcage Flash Hider, Bayonet Lug
Base model
Service history
Operators
- United States Army · adopted 1967 · as Rifle, 5.56mm, M16A1
- United States Marine Corps · adopted 1967 · as M16A1
- Army of the Republic of Vietnam · adopted 1967
Conflicts
- Vietnam War (1955-1975)
- Cambodian Civil War (1967-1975)
- Gulf War (1990-1991)
Production
Production years: 1967-1983
Colt Model 603; superseded by the M16A2 in U.S. service from the mid-1980s but remained in reserve and allied use for decades
Origin
Country of origin: United States
Designer: Eugene Stoner
Discontinued: 1983
Notes
The M16A1 is the Colt Model 603. It retained the 1:12 twist barrel optimized for the 55-grain M193 cartridge and full-auto fire selector (safe/semi/auto). Production transitioned to the heavier A2 standard in the early 1980s.
Background
Early M16A1 rifles arrived in Vietnam without cleaning kits and with the false assurance that the rifle was 'self-cleaning,' contributing to fatal jams; the chrome-lined chamber and a dedicated cleaning regimen later restored confidence in the platform.