the forward mount still has good threads it's just the back I'm worried about. I've considered both the weld and retap, and the larger hole method. I just really don't want to take the chance of completely fuggering up this gun so I am being very cautious with whatever action I take.
would applying loctite to the holes and then loctiting the screws give enought hold that the front half could hold it in place or would that be a poor choice?
#1 choice is the next size up on the screw. This works IF you have enough steel to work with.
#2 choice is a heli-coil or thread-sert repair. You can get these ultra small sizes but they are spendy, $70-100 for the kit.
TIG weld would safe one the rear of the receiver.