I am trying to gain knowledge here, so please help me out. I have been plugging numbers into a ballistics calculator and comparing them to my actual experience and they don't match. I live in Michigan and target shoot somewhere around 700 feet elevation. might be 650, but its low, one way or the other. I will zero and target shoot at home and be all great. Get to Wyoming for pronghorn and I constantly shoot way higher. The ballistics charts basically tell me my POI should only change about 3" out to 500 yards. I am entering all the data for each location. However, real world, I shoot a foot or more high at 500 compared to Michigan. Then on to Colorado and it gets even worse as elevation goes from 5000 to 8000 where we hunt. I'm Obviously missing something in the calculations. Any insight?

Example: Boone and Crocket reticle
Michigan 200 yard zero, 2nd cross at 360, third at 440, hash at 525
Wyoming, 200 zero, 2nd cross about 380, third 535, dont know hash or post
Colorado, 200 zero, 400 second cross, dont know other marks.

I have since started using a CDS dial and still working on the details, but so far good to 515 in wyoming and 640 in Michigan. dial is off a bit in Michigan, but pretty close. actually shot high and finally caught up at 640. 300 was high, I was high at 415 and 530 (had to under dial the yardage to hit).

When I leave all factors the same and change the atmospheric conditions, elevations change very little. Humidity had almost zero effect. Pressure had about 5" difference at 1000 yards and so did temperature. elevation had the biggest impact. All that said, out to 500 yards, according to the charts, it should only add up to about 3" difference at 500 yards.
What am I missing?

I was curious to see any answers you got, but none came. Maybe gravity is less at higher elevations, or air is thinner? I get much better gas mileage in the high plains which I attribute to less air resistance. Proves that you need to check aim vs impact points when you get where you're going. What is the caliber, MV, and load?

I now see the question is addressed in another thread about elevation

It sounds like you are calculating all the POI`s instead of shooting them in Mi. Is this correct? You don`t mention if the ammo is factory or handloaded. The reason I mention this, is that most loaders can crony their loads, and know the BC of the bullets they are using, and develope CU data from that, then shoot to varify.
If you are NOT doing this varification, calculations can be way off.

The part in bold above makes me wonder if you might be mixing up corrected and absolute pressure measurements? Depending what you're shooting of course, I'd expect both pressure and temp to make more difference than that at 1000. You might try going to just a density altitude measurement to simplify that. There is a good iphone app called Density Alt+ that I use for density altitude, but of course a lot of other methods are available to get there too.

Also the question above about whether you're confirming your long range dope in Michigan or not is a good one. If you're only zeroing and not confirming drops farther out, you probably don't have the calculator trued well to start with. If your inputs are correct and it's all trued to match actual drops in Michigan, the calculator should get you pretty close when changing atmospherics for other areas.

In my experience if you imputbaccurAte dates the targeting software will give accurate info out.

There is something called gravitational time dilation. Time goes faster in the presents of more gravity.
There is slightly less gravity farther from the center of the earth than at the highest mountains.

As per usual,there's farrrrrrrrrr more "weirdness" in optics and their erectors,than software.

Hint......................

Holy chit, wow just wow. I guess air density doesn’t mean much but time dilation that effects satellites that are 12,500 miles up by microseconds makes all the difference .

I hand load. I guess I'm doing it backwards. I shoot and hunt and get my real world data. Then I input my load info into hornaday ballistics online to see where it "should be" and try to figure out where I should hit at different locations where I hunt. It's not often possible for me to shoot out at longer distance prior to hinting. Usually only 200 or 300 yards. Maybe I should use a better program. I'm basically trying to get the program to match my real world results and I cant do it.

Ballistics are pretty well understood, the mathematical formulas to model a bullet's flight path were worked out by the army about 100 years ago. If your ballistic program isn't matching your real life drops then something you're putting into the program is wrong or your scope isn't tracking right as BS says.

Zeros can and will change from one area to another, just because it's zeroed at 200 in Michigan doesn't mean it'll be zeroed at 200 in Colorado. Re-zero in Colorado and the ballistic solution should match the drops unless you've entered bad data.

ALL scopes are suspect...until PROVEN otherwise. A plumb line on paper,covering an erector's FULL latitude,will have folks pinpointing woes and connecting dots,faster than anything else.

Hint......................

Yes, prove the scope. Also, are you shooting from a bench at home?

I fought vertical issues and second guessed a lot of things until I realized that my zero when shooting prone wasn't the same "zero" as I had from the bench. I was getting sloppy from both the bench and prone and it was noticeably worse when shooting with heavier recoiling rifles.

Just a thought. Hope you figure it out.

I've had perfect results from Hornady's calculator, once I learned how to use it, and put in the proper data. If you are shooting too high at distance, you are likely not entering the proper atmospheric data, or maybe your scope isn't telling you the truth. I have also used Nikon's Spot-On for BDC and have also found it extremely accurate, out to past 600 yds, once I enter the right data. Correct air temp and adjusted barometric pressure at higher altitudes matters a lot, particularly at 500+yds.

Kchuntshoot,

Mebbe wax eloquent on the wares you used,to correlate the calculations. Be SURE to cite particulars and pics both...because it WILL be fhuqking funny!

Hint..............

A friend of mine did that...working backwards. He solved it by juggeling both velocity numbers and BC. in the ballistic program.
Rember, chit in, chit out.

I don't take a camera everywhere, Stick. I'm too busy having fun to take pics. Only one of us needs "proof" that his life is worthwhile. Hint.

KchuntShoot,

At least Imagination and Pretend are free,so you can "afford" to "procure" Phantom Wares. Hint. Congratulations?!?

Bless your heart for TRYING.

Hint.

Laughing!..................

Air density at 8000 ft. is only about 70% of what it is at sea level. It makes a big difference. Gravity doesn't mean much. Barometric pressure is usually corrected to sea level numbers, and shows rise or fall, it is not expressed as actual pressure. The ballistic program should show actual pressure when altitude is entered.