Stan;
In regard to using a drill press to hold the the gun screw tightly and securely downward while turning the drill press driveshaft to twist the gun screw counter clock wise. I have used a drill press, mill/drill and a milling machine for such tasks. A proper vise to hold the gun is very much needed. And I offer this advise in the turning of the drill press, mill/drill and milling machine driveshaft to loosen the gun screw. Use a standard 1/2 inch capacity drill chuck and to turn the drill press driveshaft insert into one of the three holes (the holes where one inserts the drill chuck "key" to tighten or loosen a drill in the chuck)a 10inch or so long snug fitting shaft that has on the opposite end a larger diameter "hand hold" and use this shaft to turn the drill press chuck/drive shaft. Using a drill press (or a mill or mill/drill) that has a drive shaft lock (to hold the driveshaft from moving up/down) is desired.
I use this snug fitting shaft into the drill chuck (chuck key hole) when I am tapping screw holes by hand in my mill when I can no longer turn the chuck with only my hand. With this shaft inserted into the chuck key hole I can both turn the chuck and apply downward pressure on the mill (or drill press) while the tap is cutting threads.
Although I prefer the screw driver/ Crescent wrench method in removing "non removable screws", one needs to use what one had to do the job.
Kind regards;
Stephen Howell
