I too wish to thank you for your service for all of us! For hunting, we like to think of groups, 1"@ 100 yds, 2"@200 yds. 300 yds should be fairly within most hunters ability to effectively kill a game animal using quality glass and sufficient caliber. 270, 30-06, 308, 280 and above will work and beyond with reasonable practice. You're use to 308 nso I'd start there.