Scope is a 4-16X 50mm Leapers. First installed the scope with medium Leapers Accushot rings. The knurling on the objective housing just barely touched the barrel. I mean "barely" by a couple thousandths.
A quick swap to high Accushot rings gives the clearance you see above. Shouldering the gun and sighting revealed that I had to break my cheek contact and lift my head slightly to obtain a sight picture. It's workable, but the head position sure isn't repeatable. Unless maybe you've got a head like Herman Munster.
Swapped back to the medium rings--but added 2 layers of friction tape in the bottom half of each ring. The friction tape gave exactly this much room. No problem at all. Snugged the scope down and took a peek. Head position and eye relief looked good.
Thoughts? Unless you modify the stock comb higher, it's probably best to use a set of medium scope rings. This will limit the objective lens to no greater than 50 mm. My personal scope of choice for this gun remains the Centerpoint 4-16 X 40mm Adventure Class model. Would've used it, but I got the Leapers at the Pyramyd Moving Sale at a great price and you know how good deals go. If you're going to shoot field target or something similar, you'll need a scope with more magnification and bells and whistles. Just keep in mind the objective lens clearance issue and head position.