AR-15 variants Numbered Colt military models Numbered Colt military 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 |
| 653P | M16A1 carbine (License produced by Elisco Tools) | 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 |
| 656 | M16A1 Special Low Profile | A1 | S-1-F | Flattop | Yes | No | 20 in. | HBAR | 1:12 | Triangular | Yes | A1 |