When shooting for accuracy, you have to aim small in order to group small, so getting a scope that is clear and repeatable is very important.
I used the Leica Magnus 2.4-16x56mm scope with an illuminated L-4A reticle. This scope has a 30mm tube with a 56mm objective and offers exceptionally clear glass. This model has capped 0.1 mil turret adjustments and is a second focal plane scope. After getting on zero, I found that the scope did a great job of holding zero; and even after dialing up for long shots, it always returned to the 100-yard zero.