Just my opinion, but 4.5-14 seems GROSSLY excessive on a .308.
I believe a 2x-7x would be more magnification than you'd ever need with a .308. and the lower powers will be much more forgiving, not only of eye relief, but of mirage as well. Just a thought.
I use a 1.5-6X42 Swarovski on my .30-06 hunting rifle, and I've never felt the need for more magnification, even hunting Pronghorn Antelope out here on the open spaces of Eastern Wyoming.
The greatest enemy of the good plan is the dfream of the perfect plan.
Karl von Clausewitz.