Help with a drop chart....

BrentM

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Scope height is the most critical measurement for having your chart read correctly, assuming the chronograph is accurate. That measurement will affect close range (under 100) and midrange, even if a long range, say 800, is accurate. If everything is correct, I'd be sure you're using the correct absolute pressure from a meter, and not what the local weatherman says. I have Zeiss RF binos, and couldn't seem to get the Zeiss app chart to agree with the RF. I physically knew 800 yards was 12 moa. I was updating with the local weather. That was the problem. Once I used the absolute pressure from the built-in weather station in the RF to the app, every thing agreed.

I too think he has data input errors. Many of my clients fuss with the apps and get the data wrong. Often, it is the atmoshperic data. When I first started using an app 8 years ago I had the same issue and was using ab pressure and altitude combined. Once I figured out that using AB and altitude is wrong I was good to go.
 

Rflshootr

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Baltimore, MD
If I had to wild guess, it would be that your scope isn't moving what it says it is. I'd shoot it at 100, 3 shot groups, make sure the parallax is perfect. Use a sight-in target with 1" squares, start your aim point near the bottom and dial up in 1" increments and shoot a group at each setting. Or use 2" increments if you want to cut down on the rounds fired. By the time you get to 12"-14", you should see how well it adjusts.
 

Tulsa Reiner

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You do not do anything wrong. You always verify your drop. If you have a place where you can shoot further, 'walk' the rifle through all distances and record everything, that's your data then. That's how the shooters used to do that in the world without computers. Good luck.
I agree. For critical hunting shots at distance, I prepare by truing by scope adjustments on my dope chart by shooting at 50 or 100 yd increments and using the actual drop to enter into my chart. I trust my magnetospeed, but not the ballistic apps, because of the same problem you are having.
 

aushunter1

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Nov 16, 2012
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Australia
I've never found a ballistics calculator that is spot on.
Real world proven & practiced dope charts are the only way to go imo.

So that means you need to take the time to go through the paces.

I do this out to 1092 yards.
 

Tulsa Reiner

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I agree. For critical hunting shots at distance, I prepare by truing by scope adjustments on my dope chart by shooting at 50 or 100 yd increments and using the actual drop to enter into my chart. I trust my magnetospeed, but not the ballistic apps, because of the same problem you are having.

Let me add that following this procedure for the loads I worked up resulted in my stepson dropping his Pronghorn at 500 yds this past August.
 

BrentM

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Let me add that following this procedure for the loads I worked up resulted in my stepson dropping his Pronghorn at 500 yds this past August.
Weird. I've never seen an app not be dead on with the correct inputs. Usually anything outside the math is shooter or equipment error. I am predator hunter so having good data for small targets is no joke. I have never seen a need to shoot in increments like that. I have killed a yote at 1300 and a wolf at 980. Multiple wolves and yotes from 300-800. All using an app (shooter) or LRF (g7 and sig kilo 2400).
 

338 dude

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Weird. I've never seen an app not be dead on with the correct inputs. Usually anything outside the math is shooter or equipment error. I am predator hunter so having good data for small targets is no joke. I have never seen a need to shoot in increments like that. I have killed a yote at 1300 and a wolf at 980. Multiple wolves and yotes from 300-800. All using an app (shooter) or LRF (g7 and sig kilo 2400).
Shooter and G7BR2 !
 

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