Just bedding the recoil lug is not correct. What you want is to bed the front action ring and the backside of the recoil lug. When you do the bedding put 2 or 3 layers of masking tape on the front, sides, and bottom of the recoil lug. These areas should not contact the bedding, only the rear face and the frt action ring behind it and around the frt action screw. Go to a good hardware store and get a 4" 1/4 X 28 NF bolt cut the head off the bolt and you will have an inletting guide screw to use instead of the action screw. Make sure the action sits level before you mix the glass. In answer to your question, I like to have about 3/16 of glass behind the recoil lug. If I'm going to the trouble of glassing a stock I want to end up with a stable bed that I'll never have to worry about(and the glass is the cheap part). Leave a part of the frt action wood, say 1/4" behind the frt screw to maintain depth and when you set the action into the glass just use the rear screw enough to hold the action down to the rear mortise(the wood around the rear screw) RELEASE AGENT! RELEASE AGENT! RELEASE AGENT!
Making improvements from .5 to.75 envole much more than just a bedding job and get expensive and/or elusive. Hope this helps.