I believe there are 2 different flavors of accustock. The older one can be a real PITA. I have a savage 10T that uses a new flavor of the accustock. If you have one like mine, you need to hold the stock on the recoil pad as you put the action in to get the recoil lug to seat properly. Keep pressure downward on the barrel/action. Then I torqued the 2 action screws incrementally to whatever the spec was that I found (I think it's in the owners manual).
If action screws are only hand tight as you stated, I'm betting the stock is contacting the barrel differently every shot.
