RE: Ballistics for the 30-30
I like to sight in my rifles to be 3 inches above line of sight at the bullets highest point in it trajectory.
So.........................
If you are using 150 grain factory loads I would sight in about 2.5 inches high at 100 yards which would put you back to zero at aproximately 175 yards and about 2.5 inches low at 200 yards.
If you are shooting 170 grain factory loads then I would sight in 3 inches high at 100 yards and again you would be back to zero at aproximately 175 yards and about 3 inches low at 200 yards.
These numbers are aproximate, but should be close, and you will have to shoot at these distances to verify.
Having said all that if you are hunting where a 100 yard shot is unlikley then sight it in to be zeroed at 100 yards which will put the bullet 3 inches low at about 160 yards.