1) Install carrier key with two Bolt Carrier Key Screws to carrier using 9/64" Allen wrench or equivalent bit, torque to 35-40 inch pounds.
Colt recommends the use of Permatex No. 3 Aviation Form a Gasket in a thin coat across the bottom of the carrier key to insure a complete seal.
2) Insert assembled carrier and key into fixture with the carrier key end inserted into the open end of the fixture until it butts against the closed end of the fixture or the socket head cap screws securing the carrier key are centered between the cone tipped socket screws. Hand-tighten the cap screw in front of the carrier key to remove any movement of the carrier assembly in the fixture.
3) Using a 5/32" Allen wrench tighten EACH Allen head cap screw 1/4 to 1/2 turn at a time until you have securely staked the cap screws of the carrier key.
4) If you have raised an excessive burr that will interfere with the opera- tion of the carrier in the upper reciever, carefully remove the burr using a fine file or stone.
Reassemble the firearm according to the manufacturer’s instructions. Check for proper functioning using ACTION PROVING DUMMIES. Make sure ALL SAFETY MECHANISMS are fully functional as designed and approved by the manufacturer. If these tests prove satisfactory, test-fire the firearm with live ammunition in a SAFE and APPROPRIATE manner. IMPORTANT! Start the live ammunition tests by first loading an ACTION PROVING DUMMY, then a live round, into the magazine. Only after sev- eral tests have been conducted in this manner should additional rounds be placed in the magazine and fired.