To clarify, is the slot rounded out so you can’t turn the screw? Or did the head of the screw twist off? If the slot is rounded you can drill the screw head out then its just a matter of gripping the screw shank in a vise or with vise grips and removing the screw.

Bob

Pete,

It sounds like the slot is rounded and you can’t turn the screw. It depends on what is left of the slot.If you started this job with hardware store screwdrivers, That is where the problem started. Gunsmiths use hollow ground screwdrivers that fit the slot perfectly and have a sharp edge that bits into the slot. A cheap screwdriver are ground at a taper and naturally will want to push out which causes the rounding of the screw slot. If you still have some slot left you can grind one of your screwdrivers to fit it then use a penetrating oil on the right side plate where the threads are and let it soak for a day. Then heat up the right side plate and put more oil on it then push the screwdriver in as hard as you can while trying to turn it out. It can help to try to turn the screw in since that side of the slot is probably better condition which can break the screw free then try turn it out. Another trick with screws is to use valve grinding compound in the slot. It helps the screwdriver bit into the screw. Valve grinding compound is used in engine rebuilding and might be available at auto stores. I use it alot on Philips head screws.

If that does not work your have to drill the head off. You know the diameter of the screw by looking at the end of the screw on the right side so that is the maximum diameter you can drill. Its just like drilling out a rivet, you don’t use a drill the diameter of the head you use a drill the diameter of the rivet shank. You start with a small drill and work bigger making sure your in a exact center and you only have to drill deep enough to remove the head. Once the head comes off the side plates will come off and now its a matter of gripping the screw shank and removing it from the right side plate using the heat and oil I described above. If you don’t feel you have the expertise to drill it out then take it to a gunsmith.

Bob