instead of an egg hunt, how about a mil exercise.  blue plates are 12" 10" 8" (and that's a 2" ruler and 7" triangle).  lavender plates are 12" and 6".   IPSC are full size and 2/3rd

reticle is vortex gen2

how far away are they?

FFP or SFP scope. Power?

I'll take a guess:

2/3-size IPSC is 475 yards and the full-size is at 675.

Well... Not sure how this will do but I enjoy the practice. The blue plates are at 508 meters and the full size ipsc seemed to be at 563. What screwed with me is while the lavender plates seem to be closer than the blue plates they seemed to be at the same distance when doing the math. Can you please pm me the answers?  Thanks, This is definitely something I should practice on considering how long it took for me to do this.

the large IPSC silhouette was lased at 605 yards.  The blue plates are maybe 2 yards past it.
the plates on the first berm were lased at 535 yards

nice job milling!  you definitely would have got some hits off that estimate

btw, sorry for the delay.  i've been out of town

Damnit. Trying to figure out how I got that wrong. What's the normal amount of error when milling stuff?

dude, you were only off 10 yards, which is under 2% on the far plates.  
my guess is in an exercise like this, i'd say +/- 5% is a good goal.   in practical situations where you and the target are both moving around and you have wind and mirage and limited time, well-trained people that practice a lot are probably going to be lucky to consistently get within 10%.    larger targets are much easier than smaller ones, too

So without even scrolling down to see your update, I estimated the large IPSC to be 555m, which is 607yds.

The method I used was:

First I looked at the width and saw that it was smaller than 1 Mil, but not much smaller, so if I had to make a quick shot, I could use 450m data and favor high for a good COM shot.

For a detailed estimation:

Hold card to screen.  Match the small Mil scale from the left side of the reticle and make a scale on my card.  

Hold card to IPSC target.  Using metric IPSC dims of 45cm x 75cm, I divided mm by my read Mils to get the answer.  It was quick.

Nice pic and exercise, BTW.