bullet selection advice

I am working up a load for my 7 mag and want to f ok it right. I have had a 7 mag in the past (a bolt, very accurate great gun). I have now upgraded to the Christensen Arms Mesa in 7 mag. The gun has a vortex viper 4-16x50 hs-lr on it. I would like to work up a load and stick with it. I am...