I am taking the family from Texas to Colorado next week and driving through Raton, NM each way. I have always wanted to shoot the white buffalo they have at 1,123 yards so I'm taking my 6.5CM and 224V. My 9 yr old is starting to get excited about shooting it too. I know the dope will be different since I normally shoot at 1,000' elevation and Raton is 6,500'+. Should I expect my zero to be dramatically off as well or should it be relatively close (.1-.3 mil)?