Just getting into long range shooting myself (I don't even have my rifle yet. Its waiting at my local shop til I get home) and there is so many things you can do. By stating all the bullets you're using I assume you're reloading.
The first thing I would do, if you have a chronograph is to use the Satterlee method. If you don't have a chrony then try the OCW method. You can find out how by searching on line. Also, read my thread on OCW in the reloading section. Nomercy has some excellent advice which I am going to do.
PS: I'd start using either of these methods seating the bullets .010" off the lands if your magazine will accept them.