Ballistic question - I am stumped

[Laguna Freak]

If he verified with kestrel then it already uses the correct atmospherics. No need to confuse anyone about station pressure or density of air.

More about that in a second.

BC won't have a extreme effect from the off the box. Not at 600. Maybe at 1k but that around 1 moa most between .300 and .311 at 1k.

The problem more than likely lies in the weird system the OP is using with 2 inch high @ 100 but zero'd at 255 and the the data input into the system. Another problem could be using hornady app? If that's the case, and I could be wrong, but I'm pretty sure they only use hornady bullets…which inherently use hornady bullet form factors.

However, to revisit the atmospherics, I don't think you can have a station pressure of 26.45 in that temp at that altitude unless you were shooting in the eye of a major storm…

My logic based on a simple DA chart as admittedly I'm not a meteorologist.
View attachment 295853

Fyi; I have measured barometric pressure of 21" Hg at 4400' on a bluebird day. Powell, WY. Of course the load I was shooting that day impacted 4 moa higher than it does at 900' and 30" Hg.

 

[Maol]

Fyi; I have measured barometric pressure of 21" Hg at 4400' on a bluebird day. Powell, WY. Of course the load I was shooting that day impacted 4 moa higher than it does at 900' and 30" Hg.

4 Moa at 900 yards? for -9HG vs the OP losing 2 Moa at 600 for maybe +2.5HG (possibly).

Maybe other stuff going on though.

Note what he originally posted. @400 it is 1moa, @ 600 it is 2moa and at 1000 it is still only 2moa.

OP Calcs
400 - 2.75 moa
600 - 7.25 moa
1k - 18.75 moa

Actual drops
400 - 3.25 moa
600 - 9.25 moa
1k - 20.75

If the weather holds he said he'd rezero @100 and check it with some 162 ELDX.

 

[Laguna Freak]

4 Moa at 900 yards? for -9HG vs the OP losing 2 Moa at 600 for maybe +2.5HG (possibly).

Maybe other stuff going on though.

Note what he originally posted. @400 it is 1moa, @ 600 it is 2moa and at 1000 it is still only 2moa.

OP Calcs
400 - 2.75 moa
600 - 7.25 moa
1k - 18.75 moa

Actual drops
400 - 3.25 moa
600 - 9.25 moa
1k - 20.75

If the weather holds he said he'd rezero @100 and check it with some 162 ELDX.

Don't read more than is there.
I was referring to elevation and its attendant environmental conditions that effect external ballistics as well as verified load performance divergence at two different elevations, relative to dfanonymous' remark about being in the eye of a storm.

900' = 900 feet elevation vs 4400' elevation, not target distance.

 

[Maol]

Don't read more than is there.
I was referring to elevation and its attendant environmental conditions that effect external ballistics as well as verified load performance divergence at two different elevations, relative to dfanonymous' remark about being in the eye of a storm.

900' = 900 feet elevation vs 4400' elevation, not target distance.

Ahhhh haaa lol well that clears that up.

Still curious re the OP's getting the same drop at 600 and 1000 (yards).

 

[rakkikoira]

Thank you all who contributed. I have come to realize that there is a lot more to this than punch numbers into an app, spin the dial and you are good to 1760 yards.

 

[Mikecr]

#1 Is understanding
#2 Your capability is worked upward only with proof along the way
There are no shortcuts

 

[700Sendero]

If there is one thing I've learned, it's believe the bullet. Obviously you know what your drops ARE, so you just have to play with your software until it lines up. As others have suggested, double check ALL your inputs and I'm sure you'll find something you skipped over. I know I've done it before

 

[Maol]

If there is one thing I've learned, it's believe the bullet. Obviously you know what your drops ARE, so you just have to play with your software until it lines up. As others have suggested, double check ALL your inputs and I'm sure you'll find something you skipped over. I know I've done it before

Yep you are correct 700, the bullet does what it does. It doesn't lie. You may not like it, but there it is. Now all that's left is to tell your phone the truth.

Truing your Ballistic Calculator with Gravity Ballistics

Follow Sniper's Hide and pick up the latest information on all things precision rifle related. Sniper's Hide Training is for the serious tactical marksman.

www.snipershide.com