Everybody has gooned a screw on a gun, don't say you haven't done it cuz I'll just call you a liar. Lots of people just throw their hands up in the air and cuss and then buy a new screw,,, and then wait for a week for it to show up.
Obviously using the correct size screwdriver that fits the screw is necessary but even then sometimes the screw slot gives up and foul language generally follows.
However all is not lost and fixing a screw head is not rocket science. I've been doing it for decades, and it aint that hard.
Here's an overview of how I do it.
1. After you get the screw out, you clamp it in a Vice on the threads. You don't need to clamp it tight and destroy the threads because all you are doing is just holding the screw firmly with the underside of the head resting on the top of the vice jaws.
2. Then you take a Small Ball Peen Hammer (4oz.) and gently "toonce" the buggered parts back down to where they were originally. Sometimes you need to use a "guided blow" on the material to push the slot back closed. Don't worry about closing the slot, just don't close it all the way.
3. After the head has been reformed, take a Jewelers File and recut the slot taking care not to taper it too much.
4. Then chuck the screw in a Drill Motor and polish the head smooth on a Scotch Bright Deburring Wheel making sure the radius on the top of the screw head is maintained.
5. Drop the screw into a bottle of Birchwood Casey Cold Blue and swish it around for a while, take it out, rinse the blueing off and then dip it in Oil.
Done,,, and this took all of 2 minutes to accomplish! Don't goon it putting it back in the gun !!!
Hope some of this helps some of you cope with this common problem in a more effective way.
Randy