Angle Fire, & Station Pressure.

[Bigwheels]

I was wondering if any of you are accounting for differences in station pressure when firing ELR @ high angles. I watched a vid here some time ago on a guy (sorry, don't remember who) who was shooting @ a mile up hill, & adjusted his station pressure down for the thinner air high up near the target. I gave this a try @ the recent ELR match we had in my AO by fundamentally guessing the pressure drop for my guessed altitude change to the target. I ended up getting it right with a 1st rnd hit @ 1645 yds with a 18* angle up to the target. Now I just found a free app called triangle solver where you can enter the angle on one side with the distance, & the solver will give you the rest of the angles, & distances. Using this I entered the distance to target (1645) with the degrees (18) for one side of the triangle, & it gave me 508yds as the height to the target, which is 1525 ft. Using the rule of thumb of 1"hg/1000' elevation, & 3.5*F drop in temp/1000' elevation (using the DA model temp change) I can estimate the average air density for the shot. So in other words the pressure where I was is 27.8"hg, & the calculated pressure @ the target should be 26.2"hg with a difference of 5*F overall. These differences amount to almost 2moa in flight path.
What are your thoughts?

 

[Gunfighting Inc]

I will have to experiment with this. I have a place I can shoot ELR uphill, but I don't know how much angle I can get. Of course, I imagine your 2 MOA difference is in addition to the difference based soley on the angle?

 

[TiroFijo]

Have you taken a look at this?

exterior ballistics

 

[Bigwheels]

I will have to experiment with this. I have a place I can shoot ELR uphill, but I don't know how much angle I can get. Of course, I imagine your 2 MOA difference is in addition to the difference based soley on the angle?

Yes. This was the difference in trajectory's when the only thing changed was the station pressure. The actual angle compensation is a separate issue, as I routinely do most of my ELR shooting in the mountains so angle fire is a "normal" condition for me. I was just testing out the validity of the difference in solutions. My first attempt was @ the ELR match, & it seemed to work judging by my score, & 1st rnd hits.