In my opinion 400yds is a pretty reasonable max range if you are limited to 6X on the optic but I suspect not all will agree.
So by the same yds/magnification ratio you would limit a fixed 4X to approximately ~250yds? I don�t have any problems hitting a 3 inch diamond at 200 yds with a 6 � lb 308 win and Leupold 4X (and it is only ~ 1.25 moa rifle). Recently I have been playing around shooting groups with variables cranked up and down in power and just don�t see much difference in group size as long as the aim point is large enough. Full disclosure, my local range only goes out to 200 yds.
Hunting and target shooting are different disciplines with shared characteristics. The higher X provides a greater degree of aiming precision on target but at the same time reliability is a major consideration in the field. The individual question we all make is where to make the compromise. For me, the answer is different on a solo back pack trip in CO vs a Midwest deer hunt where a replacement rifle is a short drive away.
