Ahh the dreaded reticle drift of an el-cheapo scope. Tasco's should come with a disclaimer that says will become worthless at any moment. That said I know guys that have been blasting away for years on the same $29 value scope so go figure.

Go with the best optics, mount and ringsyou can afford or hunt open sights. A great setup for the Omega is the Leupold QR Base and Rings. Go with the meduim or high rings.

Actually there isno functionaldifference other than marketingbetween a "shotgun/muzzleloader" and a centerfirerifle scope.

Your Nikonwill work fine. Double check your mount and rings to make sure that everything is secure. Clean the threads (acetone works good)to remove all/any oilsand use a light threadlocking compound (LOCTITE 222MS PURPLEis excellent and removable if needed or 242 Blue if you need more holding power).

Tahquamenon