This may sound a bit off the wall, but I have done something similar to what Quick recommended. I've done it with a plastic stock that had stripped threads where the sling mounts go, and also on an old wooden Model 94 butt stock where the hole for the sling mount was kind of oval shaped.
The difference is I'm a bit more lazy than Tim (and didn't have the equipment he has in his shop) and didn't want the bother of re-drilling the hole... Here's what I did:

First, I enlarged the hole just a bit, then mixed up the epoxy (don't remember what kind - it was a looong time ago) put it in the enlarged hole, then covered the screw/sling mount with grease and screwed it into the hole. Some of the epoxy was forced out, and I cleaned that up right away before it had a chance to set up. Left it to cure overnight, then unscrewed the sling mount. It left a perfectly threaded hole in the cured epoxy in the stock. Ta - ra!
Only other thing is to be sure to put the epoxy in the hole first,
before even touching the grease (have used vaseline as well) - don't get
any grease anywhere near the hole or you run the risk of the epoxy not adhering to the stock.
Its kind of like bedding a barrel where you put a release of some kind (i.e. grease) on the barrel and then tighten up the stock screw to pull the barrel down into the bedding. The grease/release keeps the epoxy from adhering to the part you want to be free... like the sling mount in the above situation... that is assuming (like I did) that you may want to remove the sling mount at some point. If you don't care, just epoxy the darn thing into the stock.
Cheers
Kerry