List of Colt AR-15 and M16 rifle variants
Appearance
This article will help summarize the many Colt AR-15 variations, and also similar copies of the design. Bold model numbers are weapons used (or previously used) by U.S. Military while italic model numbers are weapons for commercial or export sale.
Colt models
Colt model no. | Name | Stock | Fire control | Rear sight | Forward assist | Case deflector | Barrel length | Barrel profile | Barrel twist | Hand guards | Bayonet Lug | Muzzle device |
---|---|---|---|---|---|---|---|---|---|---|---|---|
603 | XM16E1 | A1 | S-1-F | A1 | Yes | No | 20 in. | A1 | 1:12 | Triangular | Yes | Type 2 Duckbill |
603 | M16A1 | A1 | S-1-F | A1 | Yes | No | 20 in. | A1 | 1:12 | Triangular | Yes | A1 |
604 | M16 | A1 | S-1-F | A1 | No | No | 20 in. | A1 | 1:12 | Triangular | Yes | A1 |
605 | CAR-15 Carbine | A1 | S-1-F | A1 | No | No | 15 in. | A1 | 1:12 | Triangular | No | Type 2 Duckbill |
605A | CAR-15 Carbine | A1 | S-1-F | A1 | Yes | No | 15 in. | A1 | 1:12 | Triangular | No | Type 2 Duckbill |
605B | CAR-15 Carbine | A1 | S-F-1-3 | A1 | No | No | 15 in. | A1 | 1:12 | Triangular | No | Type 2 Duckbill |
606 | CAR-15 Heavy Assault Rifle M1 | A1 | S-1-F | A1 | No | No | 20 in. | HBAR | 1:12 | Triangular | Yes | Type 2 Duckbill |
606A | CAR-15 Heavy Assault Rifle M1 | A1 | S-1-F | A1 | Yes | No | 20 in. | HBAR | 1:12 | Triangular | Yes | Type 2 Duckbill |
606B | CAR-15 Heavy Assault Rifle M1 | A1 | S-F-1-3 | A1 | Yes | No | 20 in. | HBAR | 1:12 | Triangular | Yes | Type 2 Duckbill |
607 | CAR-15 SMG | 1st Generation | S-1-F | A1 | No | No | 10 in. | A1 | 1:12 | Short Triangular | No | Type 1 and 2 Duckbill and 3.5" Moderator |
607A | CAR-15 SMG | 1st Generation | S-1-F | A1 | Yes | No | 10 in. | A1 | 1:12 | Short Triangular | No | Type 1 and 2 Duckbill and 3.5" Moderator |
607B | CAR-15 SMG | 1st Generation | S-F-1-3 | A1 | No | No | 10 in. | A1 | 1:12 | Short Triangular | No | Type 1 and 2 Duckbill and 3.5" Moderator |
608 | CAR-15 Survival Rifle | Tubular | S-1-F | A1 | No | No | 10 in. | A1 | 1:12 | Short Round | No | Conical or 3.5" Moderator |
609 | XM177E1 | 2nd Generation | S-1-F | A1 | Yes | No | 10 in. | A1 | 1:12 | Short Ribbed | No | 3.5" or 4.5" Moderator |
610 | XM177 or GAU-5/A | 2nd Generation | S-1-F | A1 | No | No | 10 in. | A1 | 1:12 | Short Ribbed | No | 3.5" or 4.5" Moderator |
610B | CAR-15 SMG | 2nd Generation | S-F-1-3 | A1 | No | No | 10 in. | A1 | 1:12 | Short Ribbed | No | 3.5" or 4.5" Moderator |
619 | XM177E1 | 2nd Generation | S-1-F | A1 | Yes | No | 10 in. | A1 | 1:12 | Short Ribbed | No | 3.5" or 4.5" Moderator |
620 | XM177 | 2nd Generation | S-1-F | A1 | No | No | 10 in. | A1 | 1:12 | Short Ribbed | No | 3.5" or 4.5" Moderator |
629 | XM177E2 | 2nd Generation | S-1-F | A1 | Yes | No | 11.5 in. | A1 | 1:12 | Short Ribbed | No | 4.5" Moderator |
639 | XM177E2 | 2nd Generation | S-1-F | A1 | Yes | No | 11.5 in. | A1 | 1:12 | Short Ribbed | No | 4.5" Moderator or A1 |
640 | XM177E2 | 2nd Generation | S-1-F | A1 | No | No | 11.5 in. | A1 | 1:12 | Short Ribbed | No | 4.5" Moderator or A1 |
649 | GAU-5A/A | 2nd Generation | S-1-F | A1 | No | No | 11.5 in. | A1 | 1:12 | Short Ribbed | No | 4.5" Moderator |
651 | M16A1 carbine | A1 | S-1-F | A1 | Yes | No | 14.5 in. | A1 | 1:12 | Short Ribbed | Yes | A1 |
652 | M16A1 carbine | A1 | S-1-F | A1 | No | No | 14.5 in. | A1 | 1:12 | Short Ribbed | Yes | A1 |
653 | M16A1 carbine | 2nd Generation | S-1-F | A1 | Yes | No | 14.5 in. | A1 | 1:12 | Short Ribbed | Yes | A1 |
654 | M16A1 carbine | 2nd Generation | S-1-F | A1 | No | No | 14.5 in. | A1 | 1:12 | Short Ribbed | Yes | A1 |
720 | XM4/M4 | 3rd Generation | S-1-3 | A2 | Yes | Yes | 14.5 in. | M4 | 1:7 | Short Ribbed | Yes | A2 |
723 | M16A2 carbine | 3rd Generation | S-1-F | A1 | Yes | Yes | 14.5 in. | A1 | 1:7 | Short Ribbed | Yes | A1 |
725 | M16A2 Carbine (Diemaco C8) | 3rd Generation | S-1-F | A1 | Yes | Yes | 14.5 in. | A1 | 1:7 | Short Ribbed | Yes | A2 |
727 | M16A2 carbine | 3rd Generation | S-1-F | A2 | Yes | Yes | 14.5 in. | M4 | 1:7 | Short Ribbed | Yes | A2 |
733 | M16A2 Commando/M4 Commando | 3rd or 4th Generation | S-1-F | A1 or A2 | Yes | Yes or No | 11.5 in. | A1 or A2 | 1:7 | Short Ribbed | No | A1 or A2 |
735 | M16A2 Commando/M4 Commando | 3rd or 4th Generation | S-1-3 | A1 or A2 | Yes | Yes or No | 11.5 in. | A1 or A2 | 1:7 | Short Ribbed | No | A1 or A2 |
738 | M4 Commando Enhanced | 4th Generation | S-1-3-F | A2 | Yes | Yes | 11.5 in. | A2 | 1:7 | Short Ribbed | No | A1 or A2 |
777 | M4 Carbine | 4th Generation | S-1-3 | A2 | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
778 | M4 Carbine Enhanced | 4th Generation | S-1-3-F | A2 | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
779 | M4 Carbine | 4th Generation | S-1-F | A2 | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
920 | M4 Carbine | 3rd and 4th Generation | S-1-3 | Flattop | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
921 | M4A1 Carbine | 4th Generation | S-1-F | Flattop | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
921HB | M4A1 Carbine | 4th Generation | S-1-F | Flattop | Yes | Yes | 14.5 in. | M4 HBAR | 1:7 | M4 | Yes | A2 |
925 | M4E2 Carbine | 3rd or 4th Generation | S-1-3 | Flattop | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
927 | M4 Carbine | 4th Generation | S-1-F | Flattop | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
933 | M4 Commando | 4th Generation | S-1-F | Flattop | Yes | Yes | 11.5 in. | A1 or A2 | 1:7 | Short Ribbed | No | A2 |
935 | M4 Commando | 4th Generation | S-1-3 | Flattop | Yes | Yes | 11.5 in. | A1 or A2 | 1:7 | Short Ribbed | No | A2 |
938 | M4 Commando Enhanced | 4th Generation | S-1-3-F | Flattop | Yes | Yes | 11.5 in. | A2 | 1:7 | M4 | No | A2 |
977 | M4 Carbine | 4th Generation | S-1-3 | Flattop | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
978 | M4 Carbine Enhanced | 4th Generation | S-1-3-F | Flattop | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
979 | M4 Carbine | 4th Generation | S-1-F | Flattop | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
Non-Colt models
Name | Base weapon | Stock | Fire control | Rear sight | Forward assist | Case deflector | Barrel length | Barrel profile | Barrel twist | Hand guards | Bayonet Lug | Muzzle device |
---|---|---|---|---|---|---|---|---|---|---|---|---|
GUU-5/P | GAU-5/A or GAU-5A/A | 2nd or 4th Generation | S-1-F | A1 | Yes | No | 14.5 in. | A1 or M4 | 1:7 | Short Ribbed | Yes | A1 or A2 |
GUU-5/P | GAU-5/A or GAU-5A/A | 2nd or 4th Generation | S-1-F | A2 or Flattop | Yes | Yes | 14.5 in. | M4 | 1:7 | M4 | Yes | A2 |
Mekut'zar | Model 653 | 3rd Generation or Israeli | S-1-F | A1 | Yes | No | 14.5 in. | M4 | 1:7 | Short Ribbed | Yes | A2 |
Mekut'zrar | Model 653 | 2nd Generation or Isaeli | S-1-F | A1 | Yes | No | Variable; 9" average | A1 | 1:12 | Short Ribbed | No | Various |
Glossary of Terms
Stock
- 1st Generation: 2-position sliding stock that resembled a shortened fixed buttstock
- 2nd Generation: 2-position aluminum retractable stock
- 3rd Generation: 2-position fiberlite retractable stock. Introduced 1985
- 4th Generation: 4-position nylon retractable stock. Introducted 2002, designed by Picatinny Arsenal engineer Lily Ko with reinforced ribs, an angled buttplate, and a rear sling swivel
- Israeli: Rebuilt 3rd Generation stocks with 6 positions instead of 2.
- A1: Fixed stock as used on M16 and M16A1. May or may not have a trapdoor to store a cleaning kit
- A2: Improved stock used on M16A2. Longer by 5/8"
- Tubular: Fixed tubular buttstock, similar to the 2nd Generation retractable unit, using a receiver extension and triangular rear with buttplate
Fire control
- S-1-F: The selector is Safe (S) - Semi-Automatic (1) - Fully Automatic (F)
- S-1-3: The selector is Safe (S) - Semi-Automatic (1) - 3-Round Limiter (3)
- S-F-1-3: The selector is Safe (S) - Fully Automatic (F) - Semi-Automatic (1) - 3-Round Limiter (3). First Generation 4 option group
- S-1-3-F: The selector is Safe (S) - Semi-Automatic (1) - 3-Round Limiter (3) - Fully Automatic (F). Second Generation 4 option group
Rear sight
- A1: "Field sights" in which the rear sight is only adjustable for windage
- A2: Rear sight adjustable for both windage and elevation
- Flattop: Indicates carry handle and rear sight has been replaced with a MIL-STD-1913 rail
Barrel Profile
- A1: Also referred to as the "lightweight" or "pencil" profile. Original barrel profile where barrel diameter is between 0.675 and 0.575 inches.
- A2: Also referred to as the "government" or "gov't" profile. Barrel profile for which the portion of the barrel in front of handguards is thickened to 0.715 inches
- HBAR: A barrel that in some portion is thicker than government-profile, usually underneath the handguards
- M4: Government barrel profile with small portion reduced to 0.575 inches to mount M203 grenade launcher
- M4 HBAR: M4 barrel with portion under handguard thickened for sustained automatic fire
Barrel twist
- 1:12: 1 right hand twist every 12 inches (305 mm)
- 1:7: 1 right hand twist every 7 inches (177.8 mm)
Handguards
- Triangular: Triangular rifle handguards
- Short Triangular: Carbine length triangular handguards
- Short Round: Carbine length smooth round handguard
- Ribbed: Ribbed round rifle handguards
- Short Ribbed: Carbine length ribbed handguards
- M4: Oval carbine handguards with double heatshields
Muzzle device
- Type 1 Duckbill: Original three-prong flash hider
- Type 2 Duckbill: Also referred to as "three prong." A beefed-up three-prong flash hider
- A1: Also referred to as the "Birdcage" flash hider
- A2: Birdcage flash hider with bottom slots closed off to act as muzzle compensator and to prevent dust from being blown into the shooters face while in the prone position.
- 3.5" Moderator or 4.5" Moderator: Either the 3.5-inch or 4.5-inch baffled moderators
- Conical: A conical flash suppressor.