| Part Description | Colt Part | Bushmaster Part |
|---|---|---|
| (1) Pistol Grip Machine Screw | 64554 | AN501D416-16 |
| (2) Grip Lock Washer | 90001 | MS35335-61 |
| (3) Pistol Grip | 64576 | 9349127 |
| (4) Safety Detent Helical Spring | 61569 | 8448516 |
| (5) Safety Detent | 61785 | 8448631 |
| (6) Lower Receiver Extension Self Locking Screw | 64577 | 9349128 |
| (7) Buttstock Assembly | 64574 | 9349121 |
| (8) Buttcap Spacer | 64578 | 12597640 |
| (9) Takedown Pin Detent Helical Spring | 61692 | 8448586 |
| (10) Takedown Pin Detent | 61698 | 8448585 |
| (11) Takedown Pin | 61655 | 8448584 |
| (12) Pivot Pin | 62221 | 8448621 |
| (13) Buffer Assembly | 62339 | 8448615 |
| (14) Action Recoil Spring | 61581 | 8448629 |
| (15) Bolt Catch Pin | 95105 | MS16562-119 |
| (16) Bolt Catch | 62301 | 8448628 |
| (17) Bolt Catch Plunger | 62178 | 8448634 |
| (18) Bolt Catch Helical Compression Spring | 62177 | 8448633 |
| (19) Magazine Catch | 61604 | 8448638 |
| (20) Magazine Catch Button | 62032 | 8448636 |
| (21) Magazine Catch Helical Spring | 61759 | 8448637 |
| (22) Automatic Sear Pin | 61615 | N/A |
| (23) Sear | 61590 | N/A |
| (24) Selector Lever | 64564 (M16) | 9381367-S (AR15) |
| (25) Hammer And Trigger Pin | 61654 | 8448609 |
| (26) Hammer Assembly | ||
| (27) Disconnector | 64567(M16) | 9349114-S (AR15) |
| (28) Disconnector | 64566 | N/A |
| (29) Trigger Assembly | ||
| (30)Lower Receiver and Receiver Extension Assembly |