Guys,
I did a search and found one discussion on apps. It didn't answer my question. Please advise if this has been discussed before and I missed it.
I am using "shooter" on my Android. My friend uses "bullet Drop" on his iPhone. The MOA numbers are never the same. I went to Hornady's website. Again a new set of MOA numbers.
How can this be? It's math. I'm using the same set of inputs on all devices. What's up?

200 grain ELDx, 1.5 inch sight height, .626 BC, 2875 mv, 4000 feet elevation, BP 29.6, 60F, 40% humidity, no wind, G1 model, 200 yard zero, 500 yard target

I get 6.1 MOA, he gets 7.1 MOA. Not even close!

I am completely baffled. Any help is sincerely appreciated.

Ski+3

I think AIU brought up Advanced Ballistics on this site; I bought and must say it is pretty damn accurate. I don't like the "HUD" display, but the tables it generates are really good.

It's math, but each calculator is using different algorithms to come up with the drop. You'll find a g7 BC is more accurate with slippery bullets.

The best ballistics app on the market - IMO - is StrelokPro...so easy to use and fast. Even shows you how to hold with your specific reticle (and there are hundreds in the library), including how to hold on a deer or elk or aoudad, etc. Works on my iPhone or ipad.

Thanks. Will try it this weekend.