What is your hit probability on a 10" target at 1000 yards? First shot.

[QuietTexan]

I am also a bit surprised no one mentioned whether they can see mirage.

You mean in general, or during a given shot? It's kind of a fact of life for me, I guess I forget that there are places with clouds where it rains occasionally. Mirage will come out in every temperature, all it takes is full-sunlight and BAM you're dialing the zoom to 20x and wondering what's the point of an 80X scope that you can't turn up past a quarter of the way.

I mentioned it to the extent that it can displace the image of the target off the actual target. That's what's hard to explain until someone sees it - they break a shot centered on the x-ring have and hit the bottom half of the nine ring. They recheck every variable in the ballistic calculator and are still low. But it's not time to true up BC (do that and the clouds come out and you're high all the sudden), it's time to check the mirage 90* to the line if you can see it, and it'll probably be running directly away from you - you don't feel it on your face on the line so you don't notice is much.

The old adage of "don't shoot into a boil" isn't bad advice in the sense that if you have any variable head or tail wind that type of boil will likely randomly move the displaced target image in the vertical plane. It's very rare most places I shoot long range to not have cross winds to deal with, but there is one range that seems to always have a hard tail wind and it's a good place to see the erratic boil of a strong/variable wind. Gusts changing from 5-15mph pretty quickly are common there, kind of on top of a hill.

Depth of field is a big part of mirage, and mirage caps do work. Normally for a hunting shot you think you want the biggest objective lens you can get to suck in the most light possible, the brightest glass you can get, etc. But my Vortex GE came with a 35?/30?mm filter cap and on very bright days it works to increase DOF.

I think there are some folks who think with enough practice, they could hit a 10" target 95% of the time well past 1000 yards with first time shots.

No way, that's too egotistical even for me to try to claim!

Kof2M uses targets nearly the sizes of billboards because 20" at 2000 yards is a significantly harder target to hit than 10" at 1000 yards, even though they're the same angular size. Because of environmental factors/wind just like you said. They also (from what I recall) use squares/rectangles and not circles or diamonds. Diamonds are significantly harder to hit because they get less forgiving (even quicker than circles) in the more difficult variable of lateral/wind dispersion as your vertical get's off. Square or wide-rectangle targets have a lot more area to still make hits on bad shots and get feed back from the target instead of splash.

Crazy how something little like turning a square target 90* and making a diamond really changes hit probabilities.