The 2008 Remington/mars and the 2017 stiller/imuns manual has ballistics data for them zero'd at 100 yards but the mk13 army spec scopes are zero'd and ranged in meters. my mk13 mod 2 scope also has BDC turret for a 100 meter zero. I don't think either is right or wrong, but I will be zero'ing all of mine in meters.