I have the Wheeler Engineering set up, and if I'm in a hurry, and the rifle has a rail base and scope has a flat bottom to the turret housing, I simply take a 1/2 or 5/8" steel ground place the steel against the rail and turn it upwards on edge against the flat bottom of the scope turret. This makes both the turret housing flat and the top of the rail square with each other. Army Sniper method of mounting a scope. Stupid simple and it works in the right situation. (like tactical/military set ups) For everything else I use my Wheeler. It never fails.~Muirdo you use bubble levels on the action and on the scope? or do it by eye?