7.62NATO
Really sorry about the bubble...
Now just for grins - run a dollar bill under the barrel down through the stock - see if it runs all the way down to the first recoil lug without getting stuck?
Next time you take the gun apart - set the action back in the stock and start the lug screws. Then stand the gun on the recoil pad on the floor and gently tap the stock with the action in place on the floor. With the gun still verticle on the floor tighten the lug screws...
You can make a couple of shims to fit in the lug pockets - use a hole punch to put the screw hole in the shims and then remount the whole works to see if the $ bill slides down the stock. If you do not have a the teflon you can use an aluminum pop/beer can and with a pair if scissors to cut the shims. If you use the almum you will probably have to double up the shims to get the thickness you need.
Last time you took it apart di you notice any polished spots on the barrel channel of the stock?