To put this in perspective, consider that the PMII 5-25X[56] and PMII 3-20X[50] have respective Objective Bell diameters of 62mm and 57mm (a 5mm differential without attachments). So if we take the 9.5mm Objective Bell-to-Barrel Shroud clearance that 63stingray's PMII 3-20X[50] has without the Tenebraex cover and deduct 5mm of clearance to account for the larger Objective Bell diameter of the PMII 5-25X[56] there should be about 4.5mm (.177") of Objective Bell-to-Barrel Shroud clearance. FYI, 4.5mm is enough clearance to allow use of a Butler Creek Flip Open as long as the Flip Open is shaved down above the Barrel Shroud. Also, the Leupold P/N for the 34mm Mark 4 "Super High" rings is 59310.
Keith