Colt XM16E1
Colt's Manufacturing Company · Assault Rifle · Out Of Production · 1964
Also known as: Rifle, 5.56mm, XM16E1, Colt Model 603
Overview
The Colt XM16E1 was the U.S. Army trials and limited-issue model that bridged the original M16 (Model 601/602) and the standardized M16A1. Designated the Colt Model 603, it was the first member of the family to incorporate the forward assist plunger demanded by the Army so a soldier could manually close the bolt. The 'E' suffix marked its experimental/trials status; once type-classified as standard in 1967, the design was redesignated the M16A1.
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, Partial Fence Lower Receiver, Fixed Carry Handle, Birdcage Flash Hider, Bayonet Lug
Base model
Service history
Operators
- United States Army · adopted 1964 · as Rifle, 5.56mm, XM16E1
- United States Marine Corps · adopted 1965 · as XM16E1
Conflicts
- Vietnam War (1955-1975)
Production
Estimated total produced: 85,000 · Production years: 1964-1967
Approximately 85,000 XM16E1 rifles built before the line transitioned to the standardized M16A1
Origin
Country of origin: United States
Designer: Eugene Stoner
Discontinued: 1967
Notes
Colt Model 603, produced from early 1964 until the early-1967 transition to the M16A1. Introduced the 'partial fence' reinforced lower receiver around the magazine release. The Air Force/Army dispute over the forward assist delayed standardization; the Army received the forward-assist XM16E1 while the Air Force kept the assist-less M16.
Background
The first forward-assist prototype was gold-plated and hand-polished, presented by Colt president Paul Benke to Army ordnance officer Howard Wheeler in 1964 to win over a service still uneasy about a rifle with no manual bolt-closure device.