I am looking at an IOR 3-18x42 MOA/MOA with their MP8 reticle for an AR15. Seems like it might be a little heavy, but the plan is to have a scope on top and an offset Fastfire III reflex or something. Sort of like I have seen some competition AR's set up with. Really I don't know that much about this stuff, I just think it would be fun to run through some courses for practice. So I'm sort of winging it by trying to understand why Jerry Miculek or JP rifles and whoever else has their guns set up the way they do. I'm not sure if they use fixed powers with specific reticles for ranging or what. Presently the only scope I have at the moment is an NF NXS 3.5-15x56 NP-R1 mounted on an AR10. It has proven to be pretty friendly to an average shooting noob. Would this scope be appropriate for 3-gun or any AR meant to be very fast at aquiring targets? I know my NF scope at 3.5 power has been very effective at taking out multiple wild hogs at once. Just looking for input as I'm a little confused as to what I want to do. I know I love using the reflex sights because they are much faster than irons. Thank you for your time.