The rail alignment fixture is used to install the lower bolt guide rails
into a stamped receiver. Insert the rails into the receiver. secure the fixture to the rails with the screws and clamping plates provided, the front of the rails should make contact with the back of the trunnion. The lower rails should be parallel to the upper rails. Use c-clamps you provide to secure the fixture and rails in place. Ensure everything is aligned properly prior to welding. .185" spacing between rails.
