Glen, is the bracket loose on the receiver or is the wood stock loose on the bracket? If the bracket is loose on the receiver, you can try to adjust (read: bend) the ledge that the front of the bracket slides under. The bracket should fit snugly between the ledge and the bottom of the receiver.
If the stock metal is loose mounting on the gun, I'd use and have used a couple of pieces of electrical tape to take up the slop, but not make it so tight so as to prevent easy removal. A roll of tape will last a long long time and you won't have to do any defacing of the stock parts with a weld.
If the wood is loose to the bracket, tighten the screws...although I suspect this is not the case.
I think he is refering to the modification where a brass insert is put in the stock & a screw added to tighten the stock against the receiver, I think the mod was by someone over seas.