On the rear base -There’s two screws on the opposite side from the lever, fore and aft. One is the adjustment and the other is the keeper. Make sure the base is correctly positioned first (it’s an offset peg), push and hold the bottom half of the rear ring firmly towards the rear of the base then tighten the bases adjustment screw until the ring half doesn’t move around any ( Don’t over tighten though). Set the keeper screw snugly against the adjustment screw. While working the lever and sliding the ring half out of its slot make sure the ring half “snaps” into place and that the lever will fully close with ease (usually on its own). Put the front ring half into the front base and rotate until lined up true to the rear ring half, then mount the scope. Make sure to tighten the two large pitch adjustment screws in the front ring assembly “foot” after the scope is mounted and while it’s still firmly in the bases. You should be good after this.
