Calibrating Barometric Pressure

[JRinCo]

That's a nice article in the daily bulletin regarding barometric pressure and bullet drop.
So lets say that you have a hand held altimeter. How difficult are they to calibrate and take it into the field and how often do they need recalibration.

 

[Nodak7mm]

Certified altimeter cal is spendy and unnecessary for this purpose.
I would suggest you find any local airport/FBO, stop in and check the hand held against local field baro psi with the calibrated stuff they have. Alot of FBO's will also have this online. Online reporting stations (accuweather & such) are getting this from the local airport reporting stations anyway.
Rod

 

[brian427cobra]

I calibrated my Kestral 4000 using a altimeter on one of the many Boeing 737's I work on, if you can get access to a plane set the altimeter to field elevation, and read the baro off the indicator, I have double checked it twice in the last 3 years and its so close I haven't recaled it, when I use it at the various places I shoot at, I check the elevation on my GPS and adjust the Kestral to that, then I use Density Altitude and have made DA cards from -3000 to 5000 feet DA to compesate for elevation changes.

 

[brian427cobra]

Here is how to make DA cards
http://www.arcanamavens.com/LBSFiles/Shooting/Downloads/DA/

Lindy is one of the smartest men I have had the pleasure to meet in my life.

 

[JRinCo]

Thanks for the response, I've been wondering how that works.

 

[bozo699]

http://www.arcanamavens.com/LBSFiles/Shooting/Downloads/DA/

Very Interesting read,Thanks Brian

 

[Roe]

Online reporting stations...

What Nodak7mm said.
For practical purposes your Kestrel (a sensible instrument to buy) will be accurate enough for shooting without needing a recalibration. The deviation very rarely reaches significant values for shooting and said online sources will work fine for checking.

This is my solution to changing weather/ correcting for comeups, thought you might find that interesting with the above links. This card and picture isn't mine, but I made the card. It corrects for changing weather.

In this film Blog 19: Using weather data this data is used to correct a changning POI to impact centre. In the previous blogs the rifle is shot withoug making the corrections, just logging the changes.

The films also shows practical use of a weather instrument such as the Kestrel.
Hope this was of some help

 

[JRinCo]

Roe, your card looks pretty well thought out.

I was thinking more along the lines of a held device running Bryan Litz Applied Ballistics program.

 

[Roe]

Then maybe this 6mmbr Daily Bulletin will be interesting.

In this Bryan Litz tests an application for Android mobiles. There are same-math programs available for iPhone.

The system looks sweet to me (especially like the menu where you can change variables fast).

 

[JRinCo]

I just went back and watched Bryan's web site video, since I hadn't seen it for a while. I trust that Bryan has the best game in town but I think he could generate more sales, if he were to produce a short video, showing how that a hunter is going to take his product into the field and use it. I'm sure it's all very simple but there are several issues, which a lot of us are unfamiliar with.