Geissele Trigger, SD-C

Installation Instructions

If you’re unsure about installing the trigger assembly yourself, ask an experienced enthusiast for help or take it to a professional gunsmith. If you’re confident in your skills, you can usually replace the trigger assembly yourself by following these steps – at your own risk.

1. Ensure the firearm is unloaded and safe to handle before starting the installation (remove the magazine, check the chamber).
2. Remove the original trigger: detach the lower receiver and remove the original assembly per the manufacturer’s instructions (removing two pins). Keep in mind that a basic two-part trigger assembly is held under spring tension – remove it carefully. You may also need to remove the safety mechanism temporarily. Make sure all small pins and springs are accounted for.
3. Install the Geissele trigger assembly into the lower receiver, ensuring all components are properly aligned.
4. Reinsert the pins. Use the provided aluminum pin to aid in alignment during installation.
5. Verify that the trigger components move properly before reassembling the firearm. Avoid pulling the trigger when the lower receiver is detached from the firearm.
6. Reassemble the rifle and test the trigger pull to ensure proper installation. Perform a drop test to confirm the firearm does not discharge when jarred, whether the safety is engaged or not.