Consistently wrong balistic calculator

[BRTreedogs]

If you are sure that everything else is correct.
True your app by changing the velocity until it out puts what is actually getting you hits.

 

[wind gypsy]

Large errors usually can be accounted for in bad data, equipment and shooter problems.

You can’t always true out the above problems.

Start over and track test your scope before you end up chasing your tail.

^ This. Probably not truing a solution that is that jacked up unless it's solely a scope that has consistently jacked up adjustment values.

Another thought is that the OP isn't that far off from what the error would be if he has a "MOA" scope that actually adjusts 0.1 mil per click.

 

[BRTreedogs]

Imo 2950 is slow.
I'm shooting 210 vld 2970 w 76.6 H1000

78.5 is pretty hot

 

[j43097]

Imo 2950 is slow.
I'm shooting 210 vld 2970 w 76.6 H1000

78.5 is pretty hot

Thank you, good feedback

 

[seand]

Scope tracking errors are a thing. I have a leupold with a 40% error

 

[Pro953]

I would say #1, check your scope tracking. If that is accurate can you shoot from 100-600 without dialing. If so, are the drops consistent to your ballistic calculations or does it drop faster/slower at distance showing a differential from your calculations. This would make it seem like a velocity issue.

Smarter people than I here, but those would be my first two steps.


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[j43097]

I would say #1, check your scope tracking. If that is accurate can you shoot from 100-600 without dialing. If so, are the drops consistent to your ballistic calculations or does it drop faster/slower at distance showing a differential from your calculations. This would make it seem like a velocity issue.

Smarter people than I here, but those would be my first two steps.


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I think this is exactly what I will start with next time I'm out shooting.

 

[2rocky]

See if you can game your field numbers by reducing your velocity in the app until it fits your observed trajectory.

 

[BjornF16]

See if you can game your field numbers by reducing your velocity in the app until it fits your observed trajectory.

Apps are telling him to dial 7.7 MOA; his actual is 5.25 MOA.

So he is dialing less (i.e. bullet is faster than input into ballistic app).

2.5 MOA is pretty significant…something else going on besides velocity.

 

[Terrapin]

One time, I accidentally put the “sight height” (bore to scope centerline) measurement in the “sight offset” input box. I had a persistent 1.75 MOA error at all distances. Took me way to long to figure that one out.


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[j43097]

Apps are telling him to dial 7.7 MOA; his actual is 5.25 MOA.

So he is dialing less (i.e. bullet is faster than input into ballistic app).

2.5 MOA is pretty significant…something else going on besides velocity.

If I use my dialed values that got hits my velocity would have to be about 3300 fps. I don't think I could get 200g eldx to that velocity with h1000.

 

[j43097]

One time, I accidentally put the “sight height” (bore to scope centerline) measurement in the “sight offset” input box. I had a persistent 1.75 MOA error at all distances. Took me way to long to figure that one out.


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..... looking for that right now

 

[Lawnboi]

Apps are telling him to dial 7.7 MOA; his actual is 5.25 MOA.

So he is dialing less (i.e. bullet is faster than input into ballistic app).

2.5 MOA is pretty significant…something else going on besides velocity.

This. Surprised how many are recommending truing that much offset.

You won’t true out 2.5 minutes with velocity. A click or two sure but there is something seriously wrong with your data, or your scope.

Been a minute since I shot a moa scope but are we talking 4-500 yards? At those ranges you can nearly dope gravity and shoot on. You should t have to true anything and if you do it, If it’s more than a half minute I’d be doing some more digging

 

[doverpack12]

Do you have pressure correctly entered as either station or corrected to equivalent sea level. I enter the correct station pressure and no altitude which for me is between 24-26 inHg and not 30 something. There are several simple barometer apps that will give this number to you. This won’t be 100% of the issue but can compound quickly to be a large part of it. The app would be calculating drops at sea level with much heavier air
In the Hornady 4Dof app zero angle can really mess with some stuff also. I find the Hornady app difficult to understand but it has a ton of functionality. Shooter is more straightforward.

 

[EdP]

Checking the tracking to comfirm or eliminate is about as simple as it can be. Don't dial, shoot, and measure how low you hit at a given distance beyond your zero. If it matches the ballistic calculator prediction the problem is likely tracking, if not then there is another problem. Then dial in for the drop and see if you hit point of aim. If not, you have confirmed tracking is the problem.

With the Hornady calculator (and I assume all others) you have to select whether your ballistic coef number is for G1 or G7. Are you sure your have the selection correct?

 

[TheHammer]

There should be enough information in here to get you on track… as for velocities, and as some do not trust a single chrono, maybe someone you know has one to compare against but do it on the same day. I use an angle gauge with a Caldwell. 2950 isn’t that slow for a 200gr on a win mag, brass and seat procedures/depth can make a variance as well. I had to go with n570 and trimmed neck to break 3050fps w/200gr on my 24” wm while maintaining accuracy. Some rifles are fast for their manufacture make/model vs others, some are throated different, I wouldn’t get to hung up on that data point as of right now especially if she’s a tack driver. Hopefully your scope tracks true.

 

[j43097]

Wanted to let everyone one know how it went. I did the tall target test (you tube if your unfamiliar) very easy. I shot my zero at 100 yds, dialed up 19 moa (didn't have a very tall target) shot for the same spot and then measured the distance between the two groups, about 22 inches on paper. About 13% off. I'll compensate for it until hunting season is over and then the scope goes back. Thank you for all the suggestions

 

[Gone4Days]

hmmm another Leupold tracking fail.

 

[Steve300xcw]

About 13% off. I'll compensate for it until hunting season is over and then the scope goes back.

So your still planning on dialing for a shot while hunting? Am I reading that right?

 

[ResearchinStuff]

how repeatable is the 13% error?