Range Report Altitude making a difference

[dar1246]

Going on a shoot in Alliance Nebraska. The altitude where I shoot now is 1500 and Alliance is 4000ft. This will affect the bullet flight. Should I plan on the difference and print a new dope card base on this?

Does altitude affect your reloads?

 

[BOLTRIPPER]

Re: Altitude making a difference

you may find ......very small shift in your 100yd zero and MAYBE less than MOA difference out long past 700yd.....really depends on station pressure

 

[dar1246]

Re: Altitude making a difference

Will be shooting 800,900,and 1000yds. I will bring my laptop and do the math when I get there.
My program says about a full MOA less when at that altitude. I will plan on this.

Thanks

 

[michael_aos]

Re: Altitude making a difference

I typically zero locally, where the density-altitude tends to be between 7000' & 8000'.

The density altitude down in Raton lately has been between 8000' in the morning and 10,000' toward the end of the match. Targets out to 875yds.

I printed-out dope cards for 8k', 9k', 9.5k', and 10k', but I'm noticing there's not a heck of a lot of difference between them (139gr Scenar @ ~2800fps).

 

[Lindy]

Re: Altitude making a difference

You will likely not notice a change in your 100 yard zero. You will see a shift in your long-range dope, past probably 700 yards.

If you don't want to cart your laptop around you might wish to consider this approach:

Making Ballistic Cards Using Density Altitude

Note also that JBM will now do DA calulations for you:

http://www.jbmballistics.com/~jbm/cgi-bin/jbmcard-5.0.cgi

However, you might wish to read my article first for some understanding of what's going on.

 

[dar1246]

Re: Altitude making a difference

Lindy good reading. I will try that. Thanks