View Full Version : balistics calculator help? Elevation???

glock 357
09-06-2011, 8:22 PM
I'm running a ballistics calculator and trying to understand bullet drop and what not. I've ran into this field data to input the elevation. What is elevation (i know what it means in general)? Is this how high you are above the target or how high both you and the target are such as in the mountains etc?

Not that it makes a diffrence in bullet drop but noticed a slight increase in velocity and energy. I changed it based on 533ft from what the Range I go to shows on an elevation map. Both target and muzzle is at about the same level. I'd like to assume it's based on how high you are above the target but just wanted to make sure. Every little bit help especially understanding these things because ammo sure is not cheap :)

Any help understanding would be appreciated.

09-06-2011, 8:47 PM
Sounds like you're talking about Altitude. As you increase in altitude (or topographic elevation), the density of the air decreases, which has the effect of creating a slight amount less drag on the bullet in flight. So in a nutshell, if you're shooting in the mountains of the 'Stan at 3000m, you you shoot farther more accurately than at sea level because there is less drag from the atmosphere slowing the bullet down.

glock 357
09-06-2011, 9:12 PM
OK so if target and myself are at 533ft above sea level you are saying the air is lighter allowing for the bullet to fly smoother. Got it! This makes sense.


09-06-2011, 9:42 PM
Elevation is altitude, how high you are above sea level. As altitude increased, air density decreases. The air gets "thinner." The other big factor effecting air density is the temperature. Cold air is denser, hot air is less dense. All these factors have to be taken into account when dealing with bullet ballistics. When someone says "I zeroed my rifle at 100 yards" what they really should be saying is 'I zeroed my rifle at 2500 feet ASL, 70 degrees air temp, 29.92 barometric pressure, and 100 yards. Anytime one of those factors changes, the zero is going to change.