M16 rifle Summary Summary

| Colt_model_no_ | Military_designation | Barrel_Length | Barrel | Handguard_type | Buttstock_type | Pistol_grip_type | Lower_receiver_type | Upper_receiver_type | Rear_sight_type | Front_sight_type | Muzzle_device | Forward_assist | Case_deflector | Bayonet_lug | Trigger_pack |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 603 | M16A1 | 20 in (508mm) | A1 profile (1:12 twist) | Full-length triangular | Fixed A1 | A1 | A1 | A1 | A1 | A1 | Three-prong or birdcage flash suppressor | Yes | No | Yes | Safe-Semi-Auto |
| 645 | M16A1E1/PIP | 20 in (508mm) | A2 profile (1:7 twist) | Full-length ribbed | Fixed A2 | A1 | A1 or A2 | A1 or A2 | A1 or A2 | A2 | M16A1 or M16A2-style birdcage flash suppressor | Yes | Yes or No | Yes | Safe-Semi-Auto or Safe-Semi-Burst |
| 645 | M16A2 | 20 in (508mm) | A2 profile (1:7 twist) | Full-length ribbed | Fixed A2 | A2 | A2 | A2 | A2 | A2 | M16A2-style birdcage flash suppressor | Yes | Yes | Yes | Safe-Semi-Burst |
| 645E | M16A2E1 | 20 in (508mm) | A2 profile (1:7 twist) | Full-length ribbed | Fixed A2 | A2 | A2 | Flattop with Colt Rail | Flip-up | Folding | M16A2-style birdcage flash suppressor | Yes | Yes | Yes | Safe-Semi-Burst |