Ok i'm just starting out and i use a .308 with a 21 inch barrel. I want to be able to make 500 plus yard shots but 500 will do for now. I was wondering how to do the appropriate math for figureing out how to adjust my scope to hit my mark. My scope is 4-16x40mm and has 1/4" MOA at 100 yards. I plan to use federal 168gr. match ammo. I was told to calculate the adjustment for the drop was for ex. if my bullet drops 63.3" @ 500 to figure the adjustment to do this. 63.3/1.047=60.458/5=12.091 MOA is this correct? I need help. I would love for now to be able to make a 500 yard to a 600 yard shot gun). please help and thanks.