after zeroing the rifle using the M16 A4 manual 25 meter battlesight zero method, what do the elevation clicks mean, what does 1 click mean at 400 meters? at 500 meters? and so on.  Also, I zeroed the rifle set on the elevation wheel adjustment marking "Z", and not on 6/3, is that correct?

I shot a 600 yd sight in event at a local gun club yesterday and had 5/6 in the 10 ring at 300 yds, and 3/20 in the 10 ring at 600 yds with a consistent 12" group just above the 10 ring.  So, I'm dialed in pretty well, but still want to know how the elevation wheel works at different distances.  I just dialed it up 20 clicks and was hitting really well.  Could have just gotten lucky?>

dang, I must have BO.  Nobody likes my post?

50 yard
IBSZ

Quoted: .. what do the elevation clicks mean, what does 1 click mean at 400 meters?

roughly 5.5" per click - but each click is a little more then one before it as the clicks are in MOA (about 1.3 moa per click).

at 500 meters?

by this time each click represents 6.875"

and so on.  Also, I zeroed the rifle set on the elevation wheel adjustment marking "Z", and not on 6/3, is that correct?

That is the proper military method - the IBSZ listed above is an even better method - and the 200M setting you'll find more useful for general shooting.

hoping for more input-bump