Ballistics calculators and atmospheric pressure

[beginnerhunter]

So I'm playing around with ballistic calculators and I noticed there are sections for atmospheric pressure AND altitude. I'm a little confused because, all other factors equal, isn't the issue with altitude BECAUSE of the atmospheric pressure? So if you had a bullet at sea level and pressure is 29.92, and then you had a bullet at 2000 feet and pressure was ALSO 29.92, would they not fly the same? If no, why?

 

[beginnerhunter]

Nevermind I think I figured it out. They aren't specifying corrected vs absolute pressure. If you enter elevation you have to enter corrected pressure. If not, you use absolute pressure.

 

[std7mag]

Yup, temp and humidity factor into it too.
Drag racing outside Denver the pressure altitude would change drastically from morning to afternoon.

 

[Doublecluck]

Most good ballistic apps correct pressure based on elevation, (absolute pressure- not corrected) not what a weather app says. For instance at my house right now, 5000 ft elevation 40 degrees, pressure= 24.89, my 1k hold for my 7rm would be 6.12 mils. If I changed the pressure in the app using corrected pressure from the weather Channel app on my phone it would say 30.53 and call for a 6.89 mil hold and I would shoot high if I used that pressure. I’m using Hornady 4Dof app and it’s been accurate to 2k so far. Just enter altitude and temp and press save and it auto adjust pressure.

 

[Gr8bawana]

I think you would be hard pressed to find much noticeable difference at realistic hunting ranges.

 

[Hunt&FishCO]

I grew up hunting ducks in VT, hunting was part of the ‘culture’ where I grew up in rural VT. I moved to TX for college and barely hunted, I had no money and all the public areas were an hour away (access / $). Graduated and move to Austin,TX where nobody hunts and it took me years to get back into it again. We moved to CO and western big game hunting has me hooked for life.

Had I not been exposed and interested at a young age I would likely not be a late onset hunter. Access is a real issue in most places, hunting is a daunting sport to get into. Guns have generally fallen out of favor with the public due to safety concerns - which is likely impacting new hunters being introduced.