optics mount question

[The mailman]

If I mount a scope with a 56 mm optical, what height rings do I need?  I would like to keep the scope close to the receiver and barrel without touching as possible.  Help please!!

 

[xtriggerman]

56's will require the highest rings made and in some instances, that still wont be high enough on non tapered barrels.  Another factor is, is the tube long enough to put you in the best eye relief. 2 pc bases make that more critical than multi slotted one pc bases. I was a dealer when the entire bigger is better at light gathering debate raged in the late 80's.  Leupold made the case again & again that its in the coatings rather than diameter of objective lens that determine illuminating ambient light transmission to the eye. Regardless of the science back then, "looks" won out at the scope counter. Maybe things have changed since then but keep in mind, if you like a comfortable cheek weld and a fast target acquisition, I'm not sure you will be happy with a 56.