DOLOS Installation Instructions



Note: These instructions assume you are starting with an unassembled upper receiver, barrel, and gas tube / front sight post. If you are installing the DOLOS on an upper receiver that already has a barrel attached, you will have to remove the front sight, gas tube and barrel before installing the DOLOS.

1. Remove the contents of the DOLOS product box. Screw the tri-lug onto the upper receiver (the serations should face away from the upeer receiver) until the tri-lug is flush with the front of the threaded portion of the upper receiver. Screw forward until the next closest gas tube opening aligns with the gas tube opening in the upper receiver.

2. Slide the lock collar onto the barrel.

3. Attach the gas block and gas tube to the barrel, ensuring the gas tube goes through the slot in the lock collar.

4. Place a single piece of #8 shot into one of the set screw holes on the side of the trilug. Using the supplied allen wrench, install one 6-32 set screw into the tri-lug until the trilug is snug. DO NOT overtighten!

5. Install the barrel into the upper receiver by inserting the gas tube through the top gas port on the tri-lug and into the upper receiver. The barrel extension pin should line up into the slot on the upper receiver.

6. Line the lug openings on the lock collar up to the tri-lug, and push lock collar over the tri-lug. Twist the lock collar counterclockwise until the barrel is secure.

7. If the barrel is not locked to the upper receiver snuggly, remove the barrel assembly, loosen the set screw on the tri-lug, tighten the tri-lug to the next gas port hole, retighten the set screw, and repeat steps 4 thru 6.

8. If the lock collar does not turn far enough to completely cover the lugs on the tri-lug, remove the barrel assembly, loosen the set screw on the tri-lug, loosen the tri-lug to the next gas port hole, retighten the set screw, and repeat steps 4 thru 6.

9. Once the proper tri-lug location has been established, remove the barrel assembly. Place one piece of #8 shot into the set screw hole on the side of each of the two empty set screw holes. Using the supplied allen wrench, tighten one 6-32 set screw into each of the remaining two set screw positions. For best results, place a drop of blue Loctite (or equivilant) on the threads of the set screw prior to installation.

10. Screw the supplied handguard onto the lock collar.

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