Okay, so I have the basic calculations down for determining range with my mil dots, but this is my question. I know on targets, let's say a groundhog, you measure their height in mils from the top of their head to the ground, and you estimate their height standing. You then count your mils and plug and play with your formula. But what about a target like a deer, do you measure the brisket and its dimensions (average of 16in), or do you measure from the top of their back to the ground (estimated 3-4ft)? Just curious so I can get the most accurate range estimation.

Get yourself a Mildot Master it will help alot. They are pretty handy out to 5-600 yards after that trying to judge target size can really affect your corrections on the scope. I would also keep a good rangefinder handy.

Lee I guess I wasn't as clear as I should be with my question, I can calculate range using mil dot, and then adjust my turrets from there. What I am wonder is do you count mils from the top of the back of a deer to the ground like you would a human or groundhog, or do you just count from the top of the back to the bottom of the brisket?

The key to ranging with mild-dots, is 'knowing' the size of your target and getting a correct measurement in mils. By getting these two pieces of data as close to reality, the better you will be able to determine the range. Given that, I would say that the dimension on a deer that you would be able to accurately mil best is brisket to shoulder. Many times you cannot see the ground beneath them. Now if a deer is on average 16" (brisket to shoulder), I would run my calculation using 15", 16" and 17" and determine the range of your potential 'error'. Or even consider averaging the three distances and making a judgement call about the distance.

I used a Mildots quite a while back when I first started getting serious about long range deer hunting in Alberta where the shots were long field shots and the white tails were big bodied. It worked out quite well as the average size from top of the back to the bottom of the chest ran a pretty consistent 18". As previously mentioned, measuring to the ground is difficult due to grass, etc. it worked out well since one mil was the chest measurement at 500 yards. I didnt need a chart because the range adjustments using the Mildots could easily be memorized. If I thought the deer looked smaller, or I was after larger mule deer I would add or subtract 50 yards from my basic measurements taken using a 18" chest area. I was able to get range measurements out to 600 yards that ran +/- 40 yards between 400-600 yards. My range error was reduced substantially when I switched from my 308 to a flatter shooting 270WSM with high BC, high velocity loads. My max measurement range using Mildots on coyotes with a 9" chest would get me to 300 yards. The larger the target, the more precision. Also, for me, I found that the tactical milling reticule design with the finer reticle divisions could further improve ranging accuracy over the Mildot format. When I got a decent range finder, I used Mildots only as a back up RF conditions were poor or shots were at shorter ranges.

You can do it either way. All you need to know is the size of the target. It does not matter if you measure from the top of its back to the ground or if you do it from the top of its back to the bottom of the chest. If the size estimation is correct either one would work in the formula and give you the same distance. It is just easier IMO to measure from the top of the back to the ground because I use the avg size whitetail buck in my hunting area. The avg whitetail buck in my area is 3.4' tall from ground to back so that makes it really easy for me because that would just be 1 yard. The point being that you can use any part of the target to get distance as long as it is a known size.