Could you elaborate on the exact situation you'd be making these shots?
I seem to recall reading about this type of hunting in PA, where you sit on one rim of a canyon or large ravine, and snipe deer who feed at the edge of the opposite rim. The idea being that the opposite rim is a known distance, and the rifle being tested for zero on targets set up across the ravine where the deer are expected to show themselves. Is this what you had in mind? Or, more the over-the-cornfield type stuff?
Be advised that even small errors in distance judgement at that range makes for sizable elevation impact errors, and a 10 mph crosswind will move your bullet at least a yard or more sideways. You run a better chance of wounding or missing than nailing the heart-lung area unless you do everything perfectly. Having shot the .308 with 168 and 175 grain bullets extensively at 600 yards, I myself would not hunt deer at that range, and if I did I would not use either the 7mm-08 or the .308. A 7mm or .300 mag of some sort with 175-180 grain quality bullets would shoot flatter and wind-drift way less than a .308-case-based round, while still expanding enough to do enough damage.
If you still have the urge, try this - draw up and cut out some life-size deer targets out of heavy cardboard, draw in the eyes/nose/shoulder/haunch lines etc. with heavy black marker, then set them out at those ranges and pop away. See how many 'clean kills' you get vs. clean misses and wounding shots. Misses are free compared to gut or leg wounds, but see what the overall ratio of 'boiler-room' hits to everything else is, then ask yourself if you want to inflict the carboard results on real deer.
Not trying to be a wise a$$ or anything, but what you are proposing is quite difficult even for experienced long-range competitors (quite a few of whom I've seen shoot). While fun on paper targets, it may be quite unfair to an animal to whom a hunter owes a quick clean kill. Even with perfect ranging and very good wind-reading skills and shooting from a bench.
Just my $.02, good luck and let us know how you fare.