I have a .338 Rum that I have been shooting here in Texas. I have been getting pretty consistant out to 500 yards. I am hoping to start stretching my shots out to 700 or 750 yards. My question is this, I will be going elk hunting in 2014, will it be ethical to take a shot at say 500 to 600 yards just using software to give me my dope? There has to be a huge difference in shooting at sea level in 90+ degrees compared to shooting at 10k above sea level in 20 degree temps?