I have a few questions about long range shooting. I have a 300ultra mag. with a 30" barrel. The load I am using says it produces a muzzle velocity of 3370fps in a 26" barrel. How much more velocity should I get with the 30" barrel? Also, my scope allows me to adjust for wind and variable distances. If it is dead on at 100 yards. And it drops 6 inches at 300 yards, then should I just click the scope 24 clicks to adjust for the height? Sorry for all the questions but I am new.