List of Colt AR-15 and M16 rifle variants
This article describes the many variations of the Colt AR-15 and M16 rifle family of weapons produced by Colt's Manufacturing Company. Weapons patterned on the original ArmaLite AR-15 design have been produced by numerous manufacturers and have been used by nations around the world, some of which created their own variations. The tables here are split into a variety of categories and provide an overview of different subtypes. For purposes of these tables, bold model numbers are weapons used by the U.S. Military while italic model numbers are weapons for commercial or export sale. See Glossary of terms for an explanation of each column.
Colt military models
Colt has been the most visible producer of ArmaLite AR-15 pattern weapons, and the military designations M16 and M4 are heavily associated with the company. Colt has an intricate internal nomenclature system for its models, with a variety of suffixes and prefixes. Colt's systems have generally followed the times and though its model numbers originally came without prefixes, with the need to separate weapons made for civilian consumption from those made for military and law enforcement use, military models became prefixed with the code "R0". For the purposes of this table, the R0 nomenclature is obviated as this terminology did not exist in all cases, but it can be understood to be present. Military/LE models are also easily identified by their three-digit code in contrast to the four-digit codes for civilian weapons.Colt Armalite AR-15
The original Armalite AR-15 models have the charging handle located on top of the upper receiver, protected within the carrying handle.| Colt model no. | Name | Stock | Hand guards | Fire control | Rear sight | Forward assist | Case deflector | Caliber | Barrel length | Barrel profile | Barrel twist | Bayonet Lug | Muzzle device |
| 601 | ArmaLite AR-15 | A1 | Triangular | S-1-F | A1 | No | No | .223 REM | 20 in. | A1 | 1:14 1:12 | Yes | Type 1 Duckbill Type 2 Duckbill |
| 602 | ArmaLite AR-15 | A1 | Triangular | S-1-F | A1 | No | No | .223 REM | 20 in. | A1 | 1:12 | Yes | Type 2 Duckbill |
Colt M16 Rifle, M4 Carbine based weapons
| Colt model no. | Name | Stock | Hand guards | Fire control | Rear sight | Forward assist | Case deflector | Caliber | Barrel length | Barrel profile | Barrel twist | Bayonet Lug | Muzzle device |
| 603 | XM16E1 M16A1 | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 20 in. | A1 | 1:12 | Yes | Type 2 Duckbill or A1 Birdcage |
| 603 | M16S1 | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 20 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 603K | M16A1 | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 20 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 604 | M16 | A1 | Triangular | S-1-F | A1 | No | No | .223 REM | 20 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 605 | CAR-15 Dissipator | A1 | Triangular | S-1-F | A1 | No | No | .223 REM | 15 in. | A1 | 1:12 | No | Type 2 Duckbill |
| 605A | CAR-15 Dissipator | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 15 in. | A1 | 1:12 | No | Type 2 Duckbill |
| 605B | CAR-15 Dissipator | A1 | Triangular | S-F-1-3 | A1 | No | No | .223 REM | 15 in. | A1 | 1:12 | No | Type 2 Duckbill |
| 606 | CAR-15 HBAR | A1 | Triangular | S-1-F | A1 | No | No | .223 REM | 20 in. | HBAR | 1:12 | Yes | Type 2 Duckbill |
| 606A | CAR-15 HBAR | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 20 in. | HBAR | 1:12 | Yes | Type 2 Duckbill |
| 606B | CAR-15 HBAR | A1 | Triangular | S-F-1-3 | A1 | Yes | No | .223 REM | 20 in. | HBAR | 1:12 | Yes | Type 2 Duckbill |
| 607 | CAR-15 XM607 | 1st Generation | Short Triangular | S-1-F | A1 | No | No | .223 REM | 10 in. | A1 | 1:12 | No | Type 1 and 2 Duckbill and 3.5" Moderator |
| 607A | CAR-15 XM607 | 1st Generation | Short Triangular | S-1-F | A1 | Yes | No | .223 REM | 10 in. | A1 | 1:12 | No | Type 1 and 2 Duckbill and 3.5" Moderator |
| 607B | CAR-15 XM607 | 1st Generation | Short Triangular | S-F-1-3 | A1 | No | No | .223 REM | 10 in. | A1 | 1:12 | No | Type 1 and 2 Duckbill and 3.5" Moderator |
| 608 | CAR-15 Survival Rifle | Tubular | Short Round | S-1-F | A1 | No | No | .223 REM | 10 in. | A1 | 1:12 | No | Conical or 3.5" Moderator |
| 609 | XM177E1 Commando | 2nd Generation | Short Ribbed | S-1-F | A1 | Yes | No | .223 REM | 10 in. | A1 | 1:12 | No | 3.5" or 4.5" Moderator |
| 610 | XM177 Commando SMG | 2nd Generation | Short Ribbed | S-1-F | A1 | No | No | .223 REM | 10 in. | A1 | 1:12 | No | 3.5" or 4.5" Moderator |
| 610B | GAU 5/A | 2nd Generation | Short Ribbed | S-F-1-3 | A1 | No | No | .223 REM | 10 in. | A1 | 1:12 | No | 3.5" or 4.5" Moderator |
| 611 | M16A1 HBAR | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 20 in. | HBAR | 1:12 | Yes | A1 Birdcage |
| 611P | M16A1 HBAR | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 20 in. | HBAR | 1:12 | Yes | A1 Birdcage |
| 613 | M16A1 | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 20 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 613P | M16A1 | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 20 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 615 | M16 HBAR | A1 | Triangular | S-1-F | A1 | No | No | .223 REM | 20 in. | HBAR | 1:12 | Yes | A1 Birdcage |
| 616 | M16 HBAR | A1 | Round | S-1-F | A1 | No | No | .223 REM | 20 in. | HBAR | 1:12 | Yes | A1 Birdcage |
| 619 | XM177E1 Commando | 2nd Generation | Short Ribbed | S-1-F | A1 | Yes | No | .223 REM | 10 in. | A1 | 1:12 | No | 3.5" or 4.5" Moderator |
| 620 | XM177 Commando | 2nd Generation | Short Ribbed | S-1-F | A1 | No | No | .223 REM | 10 in. | A1 | 1:12 | No | 3.5" or 4.5" Moderator |
| 621 | M16A1 HBAR | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 20 in. | HBAR | 1:12 | Yes | A1 Birdcage |
| 629 | Colt XM177E2 | 2nd Generation | Short Ribbed | S-1-F | A1 | Yes | No | .223 REM or 5.56 NATO | 11.5 in. | A1 | 1:12 | No | 4.5" Moderator |
| 630 | GAU 5/A | 2nd Generation | Short Ribbed | S-1-F | A1 | No | No | .223 REM | 11.5 in. | A1 | 1:12 | No | 4.5" Moderator |
| 633 | Colt SMG | 2nd Generation | Short Round | S-1-F | A1 | No | Yes | 9mm NATO | 7 in. | A1 | 1:10 | No | - |
| 634 | Colt SMG | 2nd Generation | Short Ribbed | Conflict between S-1 and S-1-F | A1 | No | Yes | 9mm NATO | 10 in. | A1 | 1:10 | No | A1 Birdcage |
| 635 | Colt SMG | 2nd, 3rd, or 4th Generation | Short Ribbed | S-1-F | A1 | No | Yes | 9mm NATO | 10 in. | A1 | 1:10 | No | A1 Birdcage |
| 635SD | Colt SMG | 2nd Generation | Short Ribbed | S-1-F | A1 | No | Yes | 9mm NATO | 10 in. | A1 w/ integral silencer | 1:10 | No | - |
| 639 | XM177 Commando | 2nd Generation | Short Ribbed | S-1-F | A1 | Yes | No | .223 REM | 11.5 in. | A1 | 1:12 | No | 4.5" Moderator or A1 |
| 639 | Colt SMG | 2nd | Short Ribbed | S-1-3 | A1 | No | Yes | 9mm NATO | 10 in. | A1 w/ integral silencer | 1:10 | No | A2 Compensator |
| 640 | XM177 Commando | 2nd Generation | Short Ribbed | S-1-F | A1 | No | No | .223 REM | 11.5 in. | A1 | 1:12 | No | 4.5" Moderator or A1 |
| 645 | M16A1E1 | A1 | Ribbed | S-1-3 | A1 or A2 | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 Compensator |
| 645E | M16A2E1 | A2 | Ribbed | S-1-3 | Flattop | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 Compensator |
| 646 | M16A2E3 | A2 | Ribbed | S-1-F | A2 | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 Compensator |
| 649 | GAU 5/A | 2nd Generation | Short Ribbed | S-1-F | A1 | No | No | .223 REM | 11.5 in. | A1 | 1:12 | No | 4.5" Moderator |
| 650 | M16A1 carbine/CAR15 | A1 | Short Ribbed | S-1-F | A1 | Yes | No | .223 REM | 14.5 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 651 | M16A1 carbine/CAR15 | A1 | Short Ribbed | S-1-F | A1 | Yes | No | .223 REM | 14.5 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 652 | M16A1 carbine/CAR15 | A1 | Short Ribbed | S-1-F | A1 | No | No | .223 REM | 14.5 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 653 | M16A1 carbine/CAR15 | 2nd Generation | Short Ribbed | S-1-F | A1 | Yes | No | .223 REM | 14.5 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 653P | M16A1 carbine/CAR15 | 2nd Generation | Short Ribbed | S-1-F | A1 | Yes | No | .223 REM | 14.5 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 654 | M16A1 carbine/CAR15 | 2nd Generation | Short Ribbed | S-1-F | A1 | No | No | .223 REM | 14.5 in. | A1 | 1:12 | Yes | A1 Birdcage |
| 655 | M16A1 Special High Profile | A1 | Triangular | S-1-F | A1 | Yes | No | .223 REM | 20 in. | HBAR | 1:12 | Yes | A1 |
| 656 | M16A1 Special Low Profile | A1 | Triangular | S-1-F | Flattop | Yes | No | .223 REM | 20 in. | HBAR | 1:12 | Yes | A1 Birdcage |
| 701 | M16A2 | A2 | Ribbed | S-1-F | A2 | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 Compensator |
| 702 | M16A2 | A2 | Ribbed | S-1-3 | A2 | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 Compensator |
| 703 | M16A2 Prototype | A2 | Ribbed | S-1-F | A2 | Yes | Yes | 5.56 NATO | 20 in. | A1 | 1:7 | Yes | A2 Compensator |
| 705 | M16A2 | A2 | Ribbed | S-1-3 | A2 | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 Compensator |
| 707 | M16A2 | A2 | Ribbed | S-1-3 | A2 | Yes | Yes | 5.56 NATO | 20 in. | A1 | 1:7 | Yes | A2 Compensator |
| 708 | M16A2 Enhanced | A2 | Ribbed | S-1-3-F | A2 | Yes | Yes | 5.56 NATO | 20 in. | A1 | 1:7 | Yes | A2 Compensator |
| 711 | M16A2 | A2 | Ribbed | S-1-F | A1 | Yes | No and Yes | 5.56 NATO | 20 in. | A1 | 1:7 | Yes | A2 Compensator |
| 713 | M16A2 | A2 | Ribbed | S-1-3 | A2 | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 Compensator |
| 715 | M16A2 | A2 | Ribbed | S-1-F | A1 | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 Compensator |
| 719 | M16A2 | A2 | Ribbed | S-1-3 | A2 | Yes | Yes | 5.56 NATO | 20 in. | A1 | 1:7 | Yes | A2 Compensator |
| 720 | XM4 Carbine | 2nd Generation or 3rd Generation | Short Ribbed | S-1-F, S-1-3 | A1 or A2 | Earlier No, Later Yes | Earlier No, Later Yes | 5.56 NATO | 14.5 in. | A1, M4 | 1:7 | Yes | A1 or A2 Compensator |
| 723 | Colt 723 Delta Carbine | 3rd Generation | Short Ribbed | S-1-F | A1 | Earlier No, Later Yes | Earlier No, Later Yes | 5.56 NATO | 14.5 in. | Earlier A1, Later M4 | 1:7 | Yes | A2 Compensator |
| 725 | M16A2 carbine | 3rd Generation | Short Ribbed | S-1-F | A1 | Yes | Yes | 5.56 NATO | 14.5 in. | A1 | 1:7 | Yes | A2 Compensator |
| 725A | M16A2 carbine | 3rd Generation | Short Ribbed | S-1-F | A1 | Yes | Yes | 5.56 NATO | 14.5 in. | A1 | 1:7 | Yes | A2 Compensator |
| 725B | M16A2 carbine | 3rd Generation | Short Ribbed | S-1-F | A1 | Yes | Yes | 5.56 NATO | 14.5 in. | A2 | 1:7 | Yes | A2 Compensator |
| 726 | M16A2 carbine | 3rd Generation | Short Ribbed | S-1-F | A1 | Yes | Yes | 5.56 NATO | 14.5 in. | A1 | 1:7 | Yes | A1 Birdcage |
| 727 | M16A2 Government Carbine | 3rd Generation | Short Ribbed | S-1-F | A2 | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 Compensator |
| 728 | M16A2 carbine | 3rd Generation | Short Ribbed | S-1-F | A2 | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 Compensator |
| 733 | M16A2 Commando | 3rd or 4th Generation | Short Ribbed | S-1-F | A1 or A2 | Yes | Yes or No | 5.56 NATO | 11.5 in. | A1 or A2 | 1:7 | No | A1 or A2 |
| 733A | M16A2 Commando | 3rd or 4th Generation | Short Ribbed | S-1-3 | A1 or A2 | Yes | Yes or No | 5.56 NATO | 11.5 in. | A1 or A2 | 1:7 | No | A1 or A2 |
| 734 | M16A2 Commando | 3rd Generation | Short Ribbed | S-1-F | A1 or A2 | Yes | Yes or No | 5.56 NATO | 11.5 in. | A1 or A2 | 1:7 | No | A1 or A2 |
| 734A | M16A2 Commando | 3rd Generation | Short Ribbed | S-1-3 | A1 or A2 | Yes | Yes or No | 5.56 NATO | 11.5 in. | A1 or A2 | 1:7 | No | A1 or A2 |
| 735 | M16A2 Commando | 3rd or 4th Generation | Short Ribbed | S-1-3 | A1 or A2 | Yes | Yes or No | 5.56 NATO | 11.5 in. | A1 or A2 | 1:7 | No | A1 or A2 |
| 737 | M16A2 | A2 | Ribbed | S-1-3 | A2 | Yes | Yes | 5.56 NATO | 20 in. | HBAR | 1:7 | Yes | A2 |
| 738 | M16A2 Commando Enhanced | 3rd or 4th Generation | Short Ribbed | S-1-3-F | A2 | Yes | Yes | 5.56 NATO | 11.5 in. | A2 | 1:7 | No | A1 or A2 |
| 741 | M16A2 | A2 | Ribbed | S-1-F | A2 | Yes | Yes | 5.56 NATO | 20 in. | HBAR | 1:7 | Yes | A2 |
| 742 | M16A2 | A2 | Ribbed | S-1-F | A2 | Yes | Yes | 5.56 NATO | 20 in. | HBAR | 1:7 | Yes | A2 |
| 745 | M16A2 | A2 | Ribbed | S-1-3 | A2 | Yes | Yes | 5.56 NATO | 20 in. | HBAR | 1:7 | Yes | A2 |
| 746 | M16A2 | A2 | Ribbed | S-1-3 | A2 | Yes | Yes | 5.56 NATO | 20 in. | HBAR | 1:7 | Yes | A2 |
| 750 | Colt M16 Automatic Rifle | A2 | Square LMG | S-F | A2 | Yes | Yes | 5.56 NATO | 20 in. | HBAR | 1:7 | Yes | A2 |
| 777 | M4E1 Carbine | 4th Generation | M4 | S-1-F | A2 | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 |
| 778 | M4 Carbine Enhanced | 4th Generation | M4 | S-1-3-F | A2 | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 |
| 779 | M4 Carbine | 4th Generation | M4 | S-1-3 | A2 | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 |
| 901 | M16A3 | A2 | Ribbed, Rail/RIS | S-1-F | Flattop | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 |
| 905 | M16A4 | A2 | Ribbed, Rail/RIS | S-1-3 | Flattop | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 |
| 920 | M4 Carbine | 4th Generation | M4, Rail/RIS | S-1-3 | Flattop | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 |
| 921 | M4A1 | 4th Generation | M4, Rail/RIS | S-1-F | Flattop | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 |
| 921HB | M4A1 | 4th Generation | M4, Rail/RIS | S-1-F | Flattop | Yes | Yes | 5.56 NATO | 14.5 in. | M4 HBAR | 1:7 | Yes | A2 |
| 925 | M4E2 | 3rd or 4th Generation | M4, Rail/RIS | S-1-F, S-1-3 | Flattop | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 |
| 927 | M4 Government Carbine | 4th Generation | M4, Rail/RIS | S-1-F | Flattop | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 |
| 933 | M4 Commando | 4th Generation | M4, Rail/RIS | S-1-F | Flattop | Yes | Yes | 5.56 NATO | 11.5 in. | A1 or A2 | 1:7 | No | A2 |
| 935 | M4 Commando | 4th Generation | M4, Rail/RIS | S-1-3 | Flattop | Yes | Yes | 5.56 NATO | 11.5 in. | A1 or A2 | 1:7 | No | A2 |
| 938 | M4 Commando Enhanced | 4th Generation | M4, Rail/RIS | S-1-3-F | Flattop | Yes | Yes | 5.56 NATO | 11.5 in. | A2 | 1:7 | No | A2 |
| 941 | M16A3 | A2 | Ribbed, Rail/RIS | S-1-F | Flattop | Yes | Yes | 5.56 NATO | 20 in. | HBAR | 1:7 | Yes | A2 |
| 942 | M16A3 | A2 | Ribbed, Rail/RIS | S-1-F | Flattop | Yes | Yes | 5.56 NATO | 20 in. | HBAR | 1:7 | Yes | A2 |
| 945 | M16A4 | A2 | Ribbed, Rail/RIS | S-1-3 | Flattop | Yes | Yes | 5.56 NATO | 20 in. | A2 | 1:7 | Yes | A2 |
| 950 | Colt Automatic Rifle | A2 | Square LMG | S-F | Flattop | Yes | Yes | 5.56 NATO | 20 in. | HBAR | 1:7 | Yes | A2 |
| 977 | M4A1 | 4th Generation | M4, Rail/RIS | S-1-F | Flattop | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 |
| 977HB | M4A1 | 4th Generation | M4, Rail/RIS | S-1-F | Flattop | Yes | Yes | 5.56 NATO | 14.5 in. | M4 HBAR | 1:7 | Yes | A2 |
| 978 | M4 Carbine Enhanced | 4th Generation | M4, Rail/RIS | S-1-3-F | Flattop | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 |
| 979 | M4 Carbine | 4th Generation | M4, Rail/RIS | S-1-3 | Flattop | Yes | Yes | 5.56 NATO | 14.5 in. | M4 | 1:7 | Yes | A2 |
| 991 | Colt SMG | 4th Generation | M4, Rail/RIS | S-1-F | Flattop | No | Yes | 9mm NATO | 10.5 in. | A1 | 1:10 | No | A1 Birdcage |
| 992 | Colt SMG | 4th Generation | M4, Rail/RIS | S-1-3 | Flattop | No | Yes | 9mm NATO | 10.5 in. | A1 | 1:10 | No | A1 Birdcage |
| Colt model no. | Name | Stock | Hand guards | Fire control | Rear sight | Forward assist | Case deflector | Caliber | Barrel length | Barrel profile | Barrel twist | Bayonet Lug | Muzzle device |