Putting a set on a FN Mauser. Once assembled I noticed the rear ring has a bit of play when locked in the base (scope not mounted). Front locks up as there is an adjustment screw. Is this normal? Is there an adjustment I'm not seeing?

Comments pls.

Ron

Look closely at the rear base. One side has the release lever on it. On the opposing side there is a wrench
Adjustable eccentric screw. The eccentric screw also has a set screw the holds the eccentric screw in place once desired engagement is attained.
To set. Loosen the set screw on the end of the eccentric screw.
Put the ring on the base.
Turn the eccentric screw until it bottoms out on the ring foot.
Remove the ring.
Turn the eccentric screw a small amount more into the ring foot.
Lock the eccentric set screw
The release leaver should not quite make it to the bottom of its travel with the ring in place.
This gives you a little extra to cam that ring foot in so it's tight.

I would add that the front ring , indeed the whole system needs to be properly fitted..Should have come with detailed instructions.