Gents,
Please lend a hand if you can. I have installed an extender ring on the front of my Ruger RSM. I bought it from Midway as a "medium" height ring. I already had a medium set of rings on the rifle. When I mounted the scope in the new extender ring (snugging the fron ring first) the scope popped out of the rear ring by 3/16 on an inch.

I ordered a 2nd medium ring for the rear to make sure I didn't have low rings installed. Same problem.

Do I need to have a "high" ring for the rear to compensate for the height of the "medium" extender ring?

Any help would be appreciated.

On a Ruger RSM, Model-77 etc. the front ring is always one size LOWER than the rear. ie:

Front ring = Medium
Rear Ring = Tall

Roi

AND just in case I might be wrong probably a good idea to double check with the Midway tech support guys