Swapping the beavertail adapter insert on your MX-1 is a straightforward process that ensures a proper fit, seamless frame alignment, and optimal ergonomic comfort for your specific host firearm. Follow this step-by-step breakdown to replace your beavertail safely and correctly.
Watch our armorer demonstrate how to quickly loosen, unmount, and secure a new alignment spacer on the workbench:
Clear your workbench and place your MX-1 chassis upside down on a flat, stable surface.
Locate the rear assembly pin, push it completely open, and slide the rear housing door backward to clear open working space for the swap.
Insert your supplied factory Allen key into the retention screw securing the beavertail spacer to the inner door framework.
Turn counter-clockwise to loosen the bolt.
Continue unscrewing until the old beavertail completely detaches from the frame assembly. Carefully pull both the spacer block and its retention screw free.
Select the correct letter-coded beavertail spacer that matches your specific handgun model and generation tracking guidelines.
Pass the retention screw through the mounting channel of the new beavertail.
Align the beavertail guides with the rear door tracks and slide it back into its nesting position.
Use the Allen key to tighten the screw clockwise until securely seated.
🛑 Alignment Check: Ensure the newly mounted beavertail is firmly in place and displays zero lateral movement, wiggle, or loose gaps before proceeding.
Slide the rear housing door completely forward back into its closed position.
Reinsert the rear retention pin to lock the entire assembly together. Your chassis is now perfectly configured and ready for firearm insertion.