Have the same gun in SS and just posted about it in the Ruger forum further down. Mine had to be glassbedded before it would shoot. Had the same exact problem and disappointment you have but at least mine turned out alright. Also as far as the ammo dumping I had the same problem on another Ruger 30-06 and while sometimes seating the trigger guard a little further back would help it became a real problem as sometimes the floorplate wouldn't even open. From what I determined the stock had been inletted a little too deep by the triggerguard. I initially used the same trick as you with shims under the center bolt but I finally glassbedded the receiver and tang and then glassbedded the trigger guard. Just laid the epoxy and dropped trigger guard into place and pushed down slightly, did not bolt it down so it would leave a thick bed. This raised the trigger guard and eliminated all problems with the floor plate and I hope contributed to the overall accuracy of the rifle. Don't give up on it yet as nothing else feels like those little compacts. Hope it helps.
