that's exactly how i confirmed, i took a known size object, put known distance away and observed how many mildots at each magnification level, from 2x to 6x.
plugging in 333 gives correct results.
increasing power requires dividing the result by appropriate power number, to account for larger picture on the same-size-reticle.
plugging in 1000 in the equation gives me distances that i know are just too long.
my comcern now is, unless there is a way to explain why 333 works, then would somehting like 'mildot' card work on my reticle?
i'm not sure that math will make sense. eg: if the card says compensate by holding-over one dot, and my dot is actually 3x the real mildot? is that possible?