The action screws are 1/4X28 and can be found at any Ace Hardware. The rear screw is the longer one. Get a few at Ace in 2 inch and 1.5" and you can cut them to length with a cutoff wheel in a Dremel. Screw on a nut prior to cutting and you'll be able to smooth up the threads after the cut by unscrewing the nut.
Bookmarks