Before reinstalling the mainspring housing and the plug, make sure that the magwell fits over the frame and sits flat. Install the threaded mainspring housing and plug into the pistol per manufacturer’s recommendations (see the owner’s manual). Start the included 6-32 X 5/16” screw into the threaded mainspring housing plug. Have the appropriate allen/hex wrench ready. Slide the magwell over the screw head (larger side of the hole). Keep the magwell centered over the frame as you tighten the screw. Tighten the screw finger tight.

Due to dimensional variations on magazines, it may be necessary to remove a minimal amount of material from your magazine's basepad for the magazine to seat properly.