Colt M16A1
- Category
- Assault Rifle
- Barrel
- 508 mm
- Weight, empty
- 3.18 kg
- Introduced
- 1967
About
What it is, and why it matters
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.
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.
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.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Colt's Manufacturing Company LLC
- Category
- Assault Rifle
- Country
- United States
- Status
- Out of production
- Produced
- 1967 to 1983
- Variant of
- Improved model
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 508 mm
- Overall length
- 986 mm
- Sight radius
- 500 mm
- Weight, empty
- 3.18 kg
- Weight, loaded
- 3.90 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Gas operated direct impingement
- Firing mechanism
- Hammer fired
- Trigger
- Single stage
- Capacity
- 20
- Magazine
- Detachable box
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Aluminum
- Barrel
- Steel
- Stock
- Polymer
- Finish
- Anodized
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 975 m/s
- Muzzle energy
- 1693 J
- Effective range
- 400 m
- Maximum range
- 2653 m
- Rate of fire
- 750 rpm
Trajectory
What the round does downrange
Solved from the muzzle figures and the bullet. The dashed rule is the effective range on the record, and the crosses are the steps the solver returned.
Features
What it has
What the record lists as fitted, drawn from the catalogue.
Forward assist
Fixed carry handle
Chrome lined chamber
Birdcage flash hider
Bayonet lug
Standing
How it compares
Each figure against the firearms of the same type and cartridge that record it, or of the same type where that cartridge has too few. Positions are read to the nearest tenth.
| Measurement | This firearm | Median | Position |
|---|---|---|---|
| Empty weightAmong 158 5.56x45mm NATO assault rifles | 3.18 kg | 3.60 kg | Lighter than about 80% |
| Overall lengthAmong 156 5.56x45mm NATO assault rifles | 986 mm | 920 mm | Longer than about 80% |
| Barrel lengthAmong 157 5.56x45mm NATO assault rifles | 508 mm | 449 mm | Longer than about 90% |
| Magazine capacityAmong 158 5.56x45mm NATO assault rifles | 20 | 30 | Among the smallest capacities |
Answers
Questions about the Colt M16A1
How much does the Colt M16A1 weigh?
The Colt M16A1 weighs 3.18 kg (7.01 lb) empty and 3.90 kg (8.60 lb) loaded.
What caliber is the Colt M16A1?
The Colt M16A1 is chambered in 5.56x45mm NATO.
How many rounds does the Colt M16A1 hold?
The Colt M16A1 holds 20 rounds, fed from a detachable box magazine.
How long is the Colt M16A1?
The Colt M16A1 is 986 mm (38.8 in) long overall, with a 508 mm (20.0 in) barrel.
Who makes the Colt M16A1?
The Colt M16A1 is made by Colt's Manufacturing Company LLC (United States). It was designed by Eugene Stoner.
When was the Colt M16A1 introduced?
The Colt M16A1 was introduced in 1967 and discontinued in 1983.
How does the Colt M16A1 operate?
The Colt M16A1 uses a gas operated direct impingement action, and its firing mechanism is hammer fired.
Compatibility
Which parts fit this firearm
Studio
Every part that mounts on this, resolved
Not a list the maker typed out: the answer comes from the mounts this firearm exposes and the interface each part needs, so it stays right when either one changes.
- Every part that mounts on any firearm in the catalogue
- Interface standards, platforms and fit overrides
- The same answers through the API and the MCP server
Requires a signed-in GunSpec account on the Studio plan. The answer is computed per part, so it is not part of the public record.
Provenance
What the record holds
Every figure above was taken from one of these pages. The confidence reflects how much of the record came from a page a claim can be checked against.
In service
- United States Army
- 1967
- United States Marine Corps
- 1967
- Army of the Republic of Vietnam
- 1967
Provenance
Confidence in this record
80%
Stockists
Where to buy
Offers link straight to the shop. GunSpec never takes the order.
No shop has listed this firearm yet
Stock and prices come from the shops themselves. If you sell this firearm, you can list it and it appears here.
List a firearmMCP
Ask an assistant about it
The same record, reached the way a person asks for it rather than the way a program does.
Ask GunSpec
Works with
Point an MCP client at GunSpec and it answers from the catalogue rather than from memory. A free key covers the read tools.
API
The call that returns this record
The same fields, in the same units, from the same endpoint the page reads.
curl --request GET \ --url 'https://api.gunspec.io/v1/firearms/m16a1' \ --header 'X-API-Key: your_key'{ "id": "m16a1", "name": "Colt M16A1", "manufacturer": { "id": "colt", "name": "Colt's Manufacturing Company LLC", "countryCode": "US", "foundedYear": 1855, "website": "https://www.colt.com", "logoUrl": null, "description": "American firearms manufacturer headquartered in Hartford, Connecticut. Founded in 1855 and now a subsidiary of Colt CZ Group, continuing production of iconic firearms including the 1911 pistol.", "status": "active", "defunctYear": null, "stateOwned": null, "makesFirearms": null, "parentId": null, "predecessorId": null, "createdAt": "2026-02-11 23:44:38", "updatedAt": "2026-02-18 03:43:38", "version": "7143c7ff3f7e156063a240f2df7b4746ee1c0394d7cd5f592d05bac43233d637" }, "category": { "id": "assault-rifle", "name": "Assault Rifle", "description": "Selective-fire rifles chambered in intermediate cartridges" }, "country_of_origin": "US", "year_introduced": 1967, "barrel_length_mm": 508, "weight_empty_g": 3180, "action_type": "gas_operated_direct_impingement"}