Some years ago I inquired of Hawke what they recommend for their mounts. Their response was thirty inch pounds for the base and fifteen for the rings. I've used those numbers ever since with good success. I use no thread locker whatsoever on my scope mounts.
I use moly paste and follow derated torque from machinery's handbook which is 10 inch pounds for the scope rings. I don't get loose screws and I am a naughty boy in that I swap scopes constantly between guns.
Depends on the material the rings and receiver are made of. The Weaver scope mounting kit says, steel rings - 20in-lbs for cap screws, 30 in-lbs for cross bolt/ clamp screws. Aluminum rings - 15 in-lbs for cap screws, 25 in-lbs for cross bolt/ clamp screws. I Loctite all threads. It is not only a thread locker, but a thread sealer, too. Helps prevents screws from rusting in steel rings.