308 w/18" barrel...set it up today. Grabbed vortex out of my 6.8 case (quick detach rings, use it for daytime and Zeus at night). Clipped it on and hit steel at 500yds on second shot. Bout 1/2 mil low at 500 but left/right was dead on.... Gonna leave it that way and call it 475 zero. Won't be lugging it around much but will work great for 300 to 600 yd shooting in rock springs from hill to hill with the Zeus...