Adjusting UDP-9i suppressor ports
If you have any doubts in your ability to perform the following actions, stop immediately and seek assistance from a qualified gunsmith. If you need clarification on any of the steps below, please contact us to speak with a member of our support team.
Always wear proper personal protective equipment (PPE) including adequate eye protection when servicing a firearm.
Your UDP9i comes with a fully adjustable port system. By opening or closing the 15 available threaded ports, the velocity of a given round can be reduced by up to 125 fps (feet per second) from its maximum velocity.
- If you plan on shooting supersonic ammo, but want maximum sound reduction, open all of the ports allowing complete system venting.
- If you plan on shooting subsonic ammo and desire to maintain as much velocity and muzzle energy as possible, close off all ports to eliminate any system venting.
- If you desire something in between, then use the set screws to open or close the ports to reach the desired velocity or muzzle energy for a given round.
To close ports
- Remove magazine, and clear chamber.
- Remove Socket head allen screws that attach handguard to mount, place them in a safe location nearby.
- Remove handguard and set aside.
- Unscrew end cap from end of suppressor core, and set aside.
- Rotate outer tube 1/4- 1/2 rotation while sliding tube over core ( Note, if cleaning intervals have not been maintained, tube may require multiple rotations while sliding to remove due to carbon buildup. See cleaning instructions for cleaning intervals and methods).
- Use the provided 3/32" T-Handle Hex wrench and thread in one of the provided 10-32 set screws till it bottoms in the hole.
- DO NOT over-tighten the screws as you can strip the thread in the barrel.
- Hand snug the set screws for the time being.
- Perform the previous 7 steps in reverse order and test for your desired requirements.
- Once the optimal setup is achieved, perform previous steps and use Loctite compound (or rockset) to keep screws from backing out during prolonged use.
- Test fire the firearm.