Per Vortex's website:

Objective O.D.: 2.3"
Main Tube O.D.: 30mm or 1.181"

Half the Objective O.D. would be 1.15" and half the main tube O.D. would be 0.590"

The Action O.D. is 1.350" while the shank of the barrel just ahead of the nut will be 1.120" at the most (large shank). So right there you already have just shy of a 1/4" gap for the objective bell so no need to add a gap distance into your calculations.

So now you know you need the centerline of the scope rings to be a minimum of 1.15" above the top of the action.
Subtract the height of your base above the action from that 1.15" figure and that will tell you how high the rings need to be (to the centerline of the rings).

If the ring manufacturer gives the height dimension to the bottom of the ring saddle, simply subtract 0.590" (1/2 of 30mm main tube diameter) from yoru height figure from above to get the height to the bottom of the saddle.