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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N/A | M16A2E2 | 20 in (508mm) | A2 profile (1:7 twist) | Full-length semi-beavertail w/ HEL guide | Retractable ACR | ACR | A2 | Flattop with Colt rail | None | A2 | ACR muzzle brake | Yes | Yes | Yes | Safe-Semi-Burst |
| 646 | M16A2E3/M16A3 | 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-Auto |
| 655 | M16A1 Special High Profile | 20 in (508mm) | HBAR profile (1:12 twist) | Full-length triangular | Fixed A1 | A1 | A1 | A1 | A1 | A1 | M16A1-style birdcage flash suppressor | Yes | No | Yes | Safe-Semi-Auto |
| 656 | M16A1 Special Low Profile | 20 in (508mm) | HBAR profile (1:12 twist) | Full-length triangular | Fixed A1 | A1 | A1 | A1 with modified Weaver base | Low Profile A1 | Hooded A1 | M16A1-style birdcage flash suppressor | Yes | No | Yes | Safe-Semi-Auto |
| 945 | M16A2E4/M16A4 | 20 in (508mm) | A2 profile (1:7 twist) | Full-length ribbed or KAC M5 RAS | Fixed A2 | A2 | A2 | Flattop with MIL-STD-1913 rail | None | A4 | M16A2-style birdcage flash suppressor | Yes | Yes | Yes | Safe-Semi-Burst |