I want to have my Leupold Custom Dial Done and the Tech at Leupold advised me to send me the information where I will be doing most of my hunting (Montana) instead of where I did my testing (Minnesota). I'm having a brain fart trying to figure this out. If my 270WSM 150g AccuBond is going 2989FPS at 1300 feet of elevation, what will it be going at the muzzle at 6500 feet of elevation? I tried to look online for a conversion but couldn't find one. TIA. PS. If there is some sort of table please provide a link.