My RVA for QB's used an offset screw.... It requires the rear cocking pin to be removed so the gun is "cock-on-open"....



The setscrew on the right presses on a delrin rod that sits against the side of the RVA threads, preventing it from turning without using a screwdriver.... I ground the head of the screw to a "pear" shape so that it has an indicator point for counting full turns....

Bob