An anemic 308 at 600 yards drops 69.4" with 5.4" of drift and takes .784 seconds to arrive.

A 7mm Rem Mag at 600 yards will drop 52.7" with 4.6" of drift and takes .687 seconds to arrive.

A 300 Win Mag at 600 yards will drop 57.0" with 4.8" of drift and takes .718 seconds to arrive.

A 338 Lapua at 600 yards will drop 61.8" with 4.4" of drift and takes .738 seconds to arrive.

Any of these will require ranging, wind consideration, and proper doping.

Troy, what caliber would you suggest to eliminate all the guesswork?