I have always zero'd my AR 556s at a confirmed 200yds (50/200) both on irons, RDS and Steiner 1-4 (it is designed for a 200m) zero. I now have a NF ATACR 1-8 with a Mil reticle so do I zero it like a precision rifle scope at 100yds or continue to zero at 200yds? (This is my first Mil reticle) Thanks!