OK I know this is elementary to you guys but I need knowledge. Just so you know, I've searched the threads to not waste anyone's time and still have many questions. I am about to sight in my first long range gun. My question is how do I properly sight-in and shoot my rifles at various ranges using a variable power scope? I have just read the parallax vs focus thread (great thread) for abouth the fifth time and I have a good understanding of what I should do to set my parallax corrections for different yaradges. I will be shooting a 300 win mag out to 500yds initially. I am just starting to handload under the instruction of my smith so I will be shooting factory loads for now.(Winchester XP3 or Hornady Custom in 150gr. are the likely rounds) I know the advertised drops for the ammo along with BC, velocity and energy. The scope is a leup 6.5-20x50 LR/T Target Dot with the side parallax adjustment. This is basically what I know. Variable power allows a shooter to increase magnification of the target. What I don't know could fill volumes. 1) What power should be used in sighting-in the rifle at a 200yd zero? 2) Should the power setting remain the same thru-out the process of dialing my zeros at longer ranges? 3) What is the effect on MOA adjustments at various powers? 4) What other questions should I have asked? I know this is basic. That's why I think its important to get it right. Believe me when I say thanks.