wow, not what I pictured. That's not just too deep, but also wallowed out. It would take even more mcguyver'ing to make it 'right'. I'd get some all thread, have the hole machined, run the all thread in there with some jb or other thread locker and then drill/tap a new hole.
Or you could talk to your shop about a keensert. Easy enough to install with the right equipment, but that hole is neither round or straight, so it's best to rely on someone with a mill.
Nothing wrong with a stud if it works, though.