Be sure the back of the scope rib clears the receiver shoulder. Contact there is a problem, so it's said. Never saw it myself.
I have. Also besides the two screws holding the rib there are two pins. When removing the rib, listen carefully for a telltale "pinging" sound. If that happens the pins are binding and that also affects accuracy. Simple enlarge the holes for the pins just enough that they no longer bind. Might as well relieve the back of the rib while you have it off the rifle.
Paul B.
