Well, the goal is to get the heel down so the barrel's front band lip will go up, creating the tension at the ferrule. In addition, with the heel clamped to the stock another friction point further back is created which further stabilizes the action's position in the stock. I think shimming under the heel would tend to defeat that.Thanks M1Aalltheway, excellent info there. I am going to try some shims from a soda can . .
Qestion . . when properly shimmed the reciever heel should be tight against the stock?? Right now there is a .020" gap there, that is alot to pull down . . . should I shim the reciever heel area as well . . maybe split the difference?? .010" on the trigger and .010" for the trigger tabs???
BTW I have a new GI (used) walnut stock on the way . .
What comes to mind is a quick and dirty method to see if getting the heel down will get the barrel up. If you have a furniture clamp, such as http://www.harborfreight.com/24-inch-ratchet-bar-clamp-spreader-46809.html , you can clamp the heel tightly to the stock without damaging either and see if you get tension at the stock ferrule. You can even do this without the trigger group installed. If that works, then the shims between the trigger group and the stock should do the trick. If it doesn't, then shim the fulcrum area under the scope mount and try the clamp trick again. Also note that aluminum soda can material is pretty thin (I think about .005") so it'll take a few layers to pull the action into the stock using the trigger group. You might try bending them accordion style so the layers will stay together.
Down the road, if you find a trigger group/stock combination that gives you a really tight lockup without the help of shims, you can use the furniture clamp instead of the trigger guard to close up the gap and then just close the trigger guard to lock everything in place. That way, you reduce stress and wear on the trigger group but still get a good tight lockup.