at the last stage of setting up my 20S, but undecided on the optic. most of my shooting will be done within 1k yds, majority staying under 700. may consider a geissele gas gun match towards the end of the year, or next. was considering the Mk5 HD in 3-18 (reticle?), used Kales 318i or even the Razor 4.5-27. What are you guys running on ur 20S? is 18X enough mag or do I need more? any feedback is appreciated before !