I got the Mannlicher Schoenauer 1908 today. It has a G&H side mount. My first G&H mount. Mounted a scope and ran out of windage, pulled off the scope and noticed the rings had numbers. I figured the #s denote offset?? swapped them and bingo can center the scope for windage. Now I am super close (bore siting) but I am bottomed out on elevation. How do I get just a smidge more down in elevation? Put a .020 shim between the front ring and base?