Gunsmithing Recommendations for Broken Screw in Saddle mount?

[Limedust]

Hi All

Shot 27 rounds yesterday; take rifle out to clean and notice that 6-40 Torx screw head (Right screw, front ring) has sheared off completely (using DNZ one piece). Any ideas about extracting the shaft? I have tried super gluing the head back and slowly cranking it out, but that didn't work. No room to carve a slot in order to use flat-head screw driver; the remainder of the screw is about a mil down from the top.

Unfortunately, I don't have a drill press . . . have considered hand drilling it, but worried about the aluminum mount and threads. I know it's a long shot, but I'm hoping the combined experience here can give me some sort of magic bullet.

Related question: Any idea how a screw head like that simply pops off? Over-torqued (used recommended 25 in/lbs)? Freak accident? Can't remember doing anything remotely violent to the cased weapon.

Thanks in advance.

 

[insight3b]

The scope was probably too heavy for aluminum mounts. As to getting the rest of the screw out. I once had a base screws head snap off. I degreased the hole and top of the screw then applied release agent to the small amount of visible threads. I then mixed up a tiny amount of JB weld and applied it to the top of the screw and filled the hole and left a dime sized bead above the hole. I put some release agent on a torx bit and after about an hour of the JB weld curing I pressed the torx bit into it nd let it sit for 24 hours. The next day the broken part of the screw came out with the JB weld