Best scope for 5-700yd varmits?

[Catfish]

I`ll try to make MOA simple. First you must know how much your bullet will drop at all yardages. Second you must know the yardage, a range finder. I your target is 400 yrds. out and the bullet will drop 8 in at 400 yrds you would crank up your scope 2 MOA. If you raise the point of impact 2 in. at 100 yrds. you will raise it 8 in. at 400 yrds, 2 x 4 = 8. You devide the bullet drop by the number of yrds in 100 and adjust your scope than many ins. It`s real simple once you understand it.