This is a link directly to Hornady.
http://www.hornady.com/store/30-06-SPRG/?page=2
If you compare the 165gr SST and the 180gr SST (or any of them really) it should be a more accurate comparison, and I think will help shed a little more light on the 165gr-180gr differences.
My personal preference for my particular rifle is Hornady 165gr Interbonds or Winchester 180gr XP3's.
Muzzle1002003004005002800/28722597/24702403/21152217/18002039/15231870/1281
Test Barrel (24") Velocity (fps) / Energy (ft-lbs)Muzzle1002003004005002800/28722597/24702403/21152217/18002039/15231870/1281Trajectory (inches)Muzzle100200300400500-1.501.800.00-7.90-22.80-46.20