Frankly, I agree with old70, at most, all you'd need is a 4x or thereabouts, in a good, solid, low mounted rig.
I use it with my .30/30, a Leupold M8-4X of ancient vintage. Even it looks a bit large in my own eyes. If you need more glass, use some good binoculars to check out the rack, then switch to the rifle to finish the job (finding the deer is job one, of course, shooting the deer is job two, and getting the deer dressed and dragged out is job three). Over-scoping the levergun has been a problem for a very long time, and overscoping ruins the good handling qualities of an otherwise handy levergun.
A simple, good quality scope will completely cancel out any need to flip the scope out of the way, and mounted solidly, is unlikely to get the scope deranged in any way. The other posters are pretty smart, best listen to them carefully.
Last edited by ratsmacker; 10/09/16.
You can roll a turd in peanuts, dip it in chocolate, and it still ain't no damn Baby Ruth.
