Ballistic apps and potential energy via gravity
- Thread starter Scotchmo
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Woops, I didn't hit save when I changed velocity..
3 MOA difference going from -15 to 15 at 500yards with 1000 fps 185 gr....so thats what, 15.75" difference predicted by hornady due to inclination change.
-Matt
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That is significant. And it would be even greater for 600yds. And Strelok does not take that into account. Strelok shows -15 and +15 degrees to have the same compensation.
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Yea and the BC on the ammo I used is probably a bit better than what you're using.
600 Yards shows
101.75 MOA vs 96.96 MOA hold overs, so 4.79 MOA...~30"? Lol well that grew a lot from 500!
Also re-checked 50 yards, shows .01 MOA which is what, .005"?
-Matt
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I would not give much regard to the Hornady ballistic app. I had it on my phone before but deleted it. I now installed it again to check.
I used their listing of the .22LR SK Standard Plus, a ammo I use a lot and still have a brick and some more on the shelf. With my rifle zeroed at 50 meter I must dial up 7MOA for 100 meter, exactly what Strelok, Element Ballistics, Chairgun and Mero calculate with the RA4 model, giving me 15mm - 25mm groups at 100 meter with POI = POA. According to Hornady app I must dial up 8MOA.
At 200 meter Strelok and others call for 25MOA which is right for my rifle and Hornady ask 30MOA, 5MOA difference at 200 meter with a 50 meter zero. In Strelok I must change the BC to 0.085 to get the same results as Hornady and that is far off.
I checked with my centrefire rifle data as well, but Hornady does not have any of the factory ammo I use in the list. The closest I can find is far off as well. Now I know why I deleted it before.
I cannot find on the Hornady app which BC values they use and also not which drag models they use. And how do you fine tune it? How do you enter custom projectiles in the app? I just don't trust that app for accurate results.
At the end, ballistic calculators are just that, a calculator to bring you in the ballpark if you use the correct data input and drag models. After that it is up to you to do the fine tuning. There is nothing that replace real life DOPE and adjustment according to that.
I still think the hits on that 25" x 23" plate is good. Considering the one rifle shot mostly on the top half and the other on the bottom half of the plate, I think the data was as near as could be without fine tuning. If the error was because of apps not accounting for the down slope shooting and extra velocity, that had an opposite result on one rifle from what would be expected and is discussed. Like Miles aka Ballisticboy say, drag models are a general calculation for a group of projectiles in a general form and shape and not for specific projectiles.
Like I said, that results on the 25" x 23" plate is damn good and not one specific factor can be blamed for nor being better.
I used their listing of the .22LR SK Standard Plus, a ammo I use a lot and still have a brick and some more on the shelf. With my rifle zeroed at 50 meter I must dial up 7MOA for 100 meter, exactly what Strelok, Element Ballistics, Chairgun and Mero calculate with the RA4 model, giving me 15mm - 25mm groups at 100 meter with POI = POA. According to Hornady app I must dial up 8MOA.
At 200 meter Strelok and others call for 25MOA which is right for my rifle and Hornady ask 30MOA, 5MOA difference at 200 meter with a 50 meter zero. In Strelok I must change the BC to 0.085 to get the same results as Hornady and that is far off.I checked with my centrefire rifle data as well, but Hornady does not have any of the factory ammo I use in the list. The closest I can find is far off as well. Now I know why I deleted it before.
I cannot find on the Hornady app which BC values they use and also not which drag models they use. And how do you fine tune it? How do you enter custom projectiles in the app? I just don't trust that app for accurate results.
At the end, ballistic calculators are just that, a calculator to bring you in the ballpark if you use the correct data input and drag models. After that it is up to you to do the fine tuning. There is nothing that replace real life DOPE and adjustment according to that.
I still think the hits on that 25" x 23" plate is good. Considering the one rifle shot mostly on the top half and the other on the bottom half of the plate, I think the data was as near as could be without fine tuning. If the error was because of apps not accounting for the down slope shooting and extra velocity, that had an opposite result on one rifle from what would be expected and is discussed. Like Miles aka Ballisticboy say, drag models are a general calculation for a group of projectiles in a general form and shape and not for specific projectiles.
Like I said, that results on the 25" x 23" plate is damn good and not one specific factor can be blamed for nor being better.
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I would not give much regard to the Hornady ballistic app. I had it on my phone before but deleted it. I now installed it again to check.
I used their listing of the .22LR SK Standard Plus, a ammo I use a lot and still have a brick and some more on the shelf. With my rifle zeroed at 50 meter I must dial up 7MOA for 100 meter, exactly what Strelok, Element Ballistics, Chairgun and Mero calculate with the RA4 model, giving me 15mm - 25mm groups at 100 meter with POI = POA. According to Hornady app I must dial up 8MOA.
I checked with my centrefire rifle data as well, but Hornady does not have any of the factory ammo I use in the list. The closest I can find is far off as well. Now I know why I deleted it before.
I cannot find on the Hornady app which BC values they use and also not which drag models they use. And how do you fine tune it? How do you enter custom projectiles in the app? I just don't trust that app for accurate results.
At the end, ballistic calculators are just that, a calculator to bring you in the ballpark if you use the correct data input and drag models. After that it is up to you to do the fine tuning. There is nothing that replace real life DOPE and adjustment according to that.
I still think the hits on that 25" x 23" plate is good. Considering the one rifle shot mostly on the top half and the other on the bottom half of the plate, I think the data was as near as could be without fine tuning. If the error was because of apps not accounting for the down slope shooting and extra velocity, that had an opposite result on one rifle from what would be expected and is discussed. Like Miles aka Ballisticboy say, drag models are a general calculation for a group of projectiles in a general form and shape and not for specific projectiles.
Like I said, that results on the 25" x 23" plate is damn good and not one specific factor can be blamed for nor being better.
You can enter in custom BC data....you're probably using incorrect data.
The app is rated 4.4 stars, if people were having as terrible of a time you are navigating it, as well as poor results, it would reflect on that rating...
I mean, you're trying to suggest the use of rifle CANT to counter wind drift...I don't think you're in a position to critique Hornady.
Further, Sterlok uses 3DOF, Hornady uses 4DOF, far more accurate....and the more accurate model to that is 6DOF...
"The free app utilizes the Hornady 4DOF™ (4 Degrees of Freedom) Ballistic Calculator, which provides trajectory solutions based on projectile drag coefficient (not ballistic coefficient) along with exact physical modeling of the projectile, its mass and aerodynamic properties. Additionally, 4DOF™ is the first publicly available program that correctly calculates the vertical shift a bullet experiences as it encounters a crosswind, referred to as aerodynamic jump.
Standard ballistic calculators consider three degrees of freedom: windage, elevation and range. But Hornady 4DOF™ adds a fourth degree — the bullet’s movement about its center of gravity and subsequent angle relative to its line of flight — for even greater accuracy."
-Matt
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Matt,
Your numbers from the Hornady app looked substantially different than what I would expect so I was suspicious of them. But I installed the app anyway hoping I’d get better predictions. After playing with it, I’d say that there are some serious math errors in their angular compensation. It’s possible that I’m doing something wrong with the inputs, but I don’t think so.
At this point, I’d agree with Caliber 22s assessment of the Hornady app.
Your numbers from the Hornady app looked substantially different than what I would expect so I was suspicious of them. But I installed the app anyway hoping I’d get better predictions. After playing with it, I’d say that there are some serious math errors in their angular compensation. It’s possible that I’m doing something wrong with the inputs, but I don’t think so.
At this point, I’d agree with Caliber 22s assessment of the Hornady app.
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I just replicated this following real world info into the Hornady app...
At 200 yards, Hornady predicts nearly the same change from -15 to 15 as real world results produced...in fact, it was under, and not over.
However, won't bother arguing, suit yourself.
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I did not suggest it but asked who is using it as I saw same use it with CF rifles and then tried it myself. Because I broke my wrist and now have same plates and screws in it, I cannot continue trying to see if it really works and was curious is somebody else tried it with air rifles with any success.
Besides, what does that has to do with comparing and evaluating a app?
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Hornady app calculated .22" change from -15 to 15 where real world tests were .38"....where Sterlok shows 0" with the above data on the Sierra 240 gr going 1300 fps at 2,500 altitude.
Think Hornday got a little closer than Sterlok here...and for a free app, if you wanna complain, feel free. If you want better results, there are paid apps that use 6DOF, ranging from $150 to $800.
-Matt
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I am happy with the results I am getting from the apps I have.
What do you think about Applied Ballistics from Bryan Litz? I never used it or a Kestrel unit.
What do you think about Applied Ballistics from Bryan Litz? I never used it or a Kestrel unit.
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Applied ballistics is supposed to be a pretty gold standard among ELR community with PB. Kestrel unit is supposed to be the cats meow that goes above and beyond what any app on your phone can do, far more computational power.
Hornady app is very well reviewed, its primarily for their bullets, however you can create custom profiles but their data will not be 100% compared to using their own ammo...and best of all, its free. 4.4/5 stars with 4,767 reviews on google play, and 4.8/5 stars with 34,052 reviews on apple store, in a day and age where maintaining over 4 stars for any app or business is very challenging. I will definitely not take peoples opinions here about the app with more than a grain of salt. To put in perspective, Sterlok has 4.5/5 on google play with 5,677 reviews and only 4/5 stars on apple store with...5 reviews. Applied ballistics = 3.4/5 on google play with 756 reviews and 3.1/5 on Apple with 110 reviews...
-Matt
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The free Hornady app seems OK for level shots. Which is what most people are doing. And I like that it appears to be taking into account the difference between shooting up versus down. But outside of that, the math for their inclination compensation is flawed.
It’s easy enough to test that in the Hornady app. Put your zero at the trajectory apex. Your compensation at that distance will be zero as expected. Now put in a substantial angle. The compensation shows as positive when it should be negative.
For inclined shots, there will be some point along the Hornady trajectory prediction that crosses with the actual trajectory, but that’s the only point where it is correct.
The Hornady app is not a good model to use for testing the original question that I posed in this thread.
It’s easy enough to test that in the Hornady app. Put your zero at the trajectory apex. Your compensation at that distance will be zero as expected. Now put in a substantial angle. The compensation shows as positive when it should be negative.
For inclined shots, there will be some point along the Hornady trajectory prediction that crosses with the actual trajectory, but that’s the only point where it is correct.
The Hornady app is not a good model to use for testing the original question that I posed in this thread.
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You're either contradicting yourself here or I do not follow, either way I have no desire to entertain the argument. The reason I brought the Hornady app into this thread is because it DID show the difference you're posing, which is the effect that gravity has based on - or + inclination angle...simple as that. The app answered your question, as well as the real world data I presented from Sierra.
You should post your issues with the App on google/apple store reviews.
-Matt
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You might not follow what I was saying.
Yes, the Hornady app gets good reviews.
Most people shoot horizontal and the Hornady app does fine for that, so the good reviews in that case are valid.
We are talking about angled shots for which the Hornady handles incorrectly. So I can’t trust its predictions in those instances, regardless of whether it shows a difference between up and down.
I’m not invested enough with the Hornady app to get involved with trying to get them to fix it.
But I do appreciate that you brought up the Hornady app as an example, because, so far, it’s the only one that appears to acknowledge the up/down difference in its calculations.
So the new question for anyone else that cares to entertain it: Is there an app that does the inclination math correctly while also taking into account a difference between an upward and downward shot?
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I never suggested to use Hornday brother.
I merely introduced it into this thread as an answer to your question, that yes, gravity does effect the incline or decline angle. If you have issues with Hornday's app, you should write a review to them OR to their devs to correct the issue you claim. I wouldn't even advise using it though unless using their ammo...All the information I see is correct and based on other forums / data they're data is quite correct.
NOTHING will beat a dope card...these ballistic apps are used as approximations to help you get close.
I am unaware of any *free* ballistic apps that will do as you ask other than what I already mentioned. Good luck.
-Matt
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Oh, and I e-mailed Igor from Sterlok on this matter on your behalf...to see if he'd consider adding such effects.
-Matt
-Matt
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Igor is quick to answer but I don't think he is to eager to do major changes to the app. A few years back I suggested / requested some practical additions and he said he will look into but nothing happened. I don't know if and what changed since he was sanctioned as I still use the last version before that.
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Worth a shot, e-mail takes a few seconds. Hopefully Scott can find an app that is well rounded like Sterlok but includes what he wants.
Maybe look into Applied Ballistics documentation, its a $29.99 app IIRC...but I am sure there has to be documentation that states what it does.
-Matt
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I appreciate that, as I am invested (time and use) in Strelok. Unfortunately, I’m currently using an iPhone so I do not have access to any updates of Strelok. Though I continue to use Strelok with the hopes that updates will be more readily available in the USA in the future.
Strelok has some other minor data errors that I’d like to see fixed as well. It’s internal data is done in meters, but when displaying yards, internally it rounds (always up) to the meter. That causes some impossible results. Small but minor errors that bug me none the less.
As I said, I’m not going to put any time into trying to get Hornady to fix their app. I’d rather stick with Strelok, especially if Igor continues to update it. And I’ll switch to a Samsung device if that means I can get updated Strelok versions.
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