For 3D competitions I use a 4X scope and a yellow clairifier in my peep I can most often see the rings as far as indoors
(vegas rounds ) I use a 6X also with a yellow clairifier just a smaller hole.. If you use to much power in a scope for 3D you will lose your target quite often and fight to see where you are.. Hope this helps and good luck..any ? feel free to email me... Joe