Thanks for the replies! When ordering scope rings do I need to order a higher size because of the 20 MOA cant?
this was a discussion in previous threads check the height of the manufacturer as you can probably get away w low-= not sure why without additional info that you need a 20 moa base the 4 -16 viper is a 600 yard scope at best and not intended for use w long range as the glass other than a clear day will fragment good for targets not precision
In the manual for that scope Vortex recommends the use of a 20 moa rail and for ranges to 800 yards. The range would also be dictated by what cartridge and bullet you are using.
In the Q&A on their webpage that question is answeredhttp://www.vortexoptics.com/product/vortex-viper-pst-4-16x50-riflescope-with-ebr-1-moa-reticle
words are important it actually says if shooting distances beyond 800 yards use a 20 moa rail "Note: If shooting at distances in excess of 800 yards with 4–16x50 or
6–24x50 models, Vortex Optics recommends use of a 20 MOA canted
Picatinny rail or 30 mm rings with adjustable offsets. These can be
purchased through companies such as Badger Ordnance, Barrett Mfg.,
EGW, Burris, and others" so I will stand by statement that for precison shooting the 4-16 x 40-50 is a 600 yard scope the glass