Marketing Hype in Ballistics - Hornady 4DOF Solver

[DocUSMCRetired]

Marketing Hype in Ballistics - The Hornady 4DOF Solver


This is the start of the Truth In Performance campaign. Applied Ballistics’ mission is to be the complete and unbiased source of external ballistics information for long range shooters. Gaining the knowledge required to master long range shooting is very difficult, even when you have good information. Unfortunately the hyper-marketing/advertising culture we live in is constantly pushing out misleading or outright false information to promote products.

In addition to exploring the unknown areas of ballistics and publishing original information, it’s also part of our mission at Applied Ballistics to address the many questions which arise from the overwhelming marketing hype.

This is a technical article that explains some of the marketing hype related to the Hornady 4 DOF ballistic solver. We go in to Aerodynamic Jump and Spin Drift. If you are interested in learning the truth about 6DOF, 3DOF, MPM, and the Aerodynamic Jump Calculation Hornady is claiming, this article will help separate the fact from fiction.

Some Lead and some Follow. AB has been modeling spin drift, Aerodynamic Jump, Coriolis, WEZ and other advanced calculations for a long time. We literally wrote the book on it, and have been providing these calculations in our solver for years. In the end, its results that matter, so trust the professionals that the professionals go to.

Article: http://appliedballisticsllc.com/Truth In Performance/Hornady4DOF.pdf

 

[dcali]

Is Hornady not going to release their drag tables? If so, that is very disappointing. They ought to follow Lapua's lead on this. It's disappointing to see a trend towards obfuscation of the math behind ballistics calculators, as if someone has some secret sauce that wasn't worked out decades ago.

 

[Berger.Fan222]

Is Hornady not going to release their drag tables? If so, that is very disappointing. They ought to follow Lapua's lead on this. It's disappointing to see a trend towards obfuscation of the math behind ballistics calculators, as if someone has some secret sauce that wasn't worked out decades ago.

Sierra's velocity dependent G1 BC was the first step in this direction. Then AB provided velocity dependent G1 and G7 BCs for a bunch of different bullets. It's not to difficult to triangulate that AB probably has drag tables for many Berger bullets, but from what I can tell, they are selling them rather than releasing them freely (custom drag curves or some such thing).

What percentage of shooters can even really understand and make use of custom drag curves? It is something of a tech support burden to release information to the whole community that only a few percent can use meaningfully. This may well be why neither Berger nor Hornady have made a general (free) release of their custom drag curves.

For most folks, the mathematics of differential equations is already obfuscated enough, and there is not a big difference (to their understanding of what is really happening) whether there are 3, 4, or 6 differential equations involved. The bullet companies seem to be doing their best to communicate in a way their customers can understand. Sure, they mix in marketing, but I'm not sure any are much better or much worse than the others.

I need to have a closer look at what Hornady has really done here.

But in any case, anyone who really knows how ballistic calculators work can fairly simply recreate the underlying drag table from computed trajectories. I bet you could write a spreadsheet to do it in a couple of hours. Why wait for Hornady to release their drag tables since you could do it?

 

[JPeelen]

This is the start of the Truth In Performance campaign. ...

I must say I am deeply disappointed by what I see as Applied Ballistic's polemic overreaction to the Hornady calculator. For example, 4DOF has previously been used in ballistics for the Modified Point Mass Model and is not Hornady's invention. The text in the PDF file you link to is in my view in no way up to the professionals standards your customers associate with AB. Looking at your achievements I see absolutely no reason to react in such a way.

 

[JPeelen]

But in any case, anyone who really knows how ballistic calculators work can fairly simply recreate the underlying drag table from computed trajectories. I bet you could write a spreadsheet to do it in a couple of hours.

The problem is not in the spreadheet level computation, but to get reliable, exact data in the first place. That is REALLY hard and laborious. If it were easy, neither Applied Ballistics nor Hornady would keep the custom drag curves to themselves.

 

[DocUSMCRetired]

Sierra's velocity dependent G1 BC was the first step in this direction. Then AB provided velocity dependent G1 and G7 BCs for a bunch of different bullets. It's not to difficult to triangulate that AB probably has drag tables for many Berger bullets, but from what I can tell, they are selling them rather than releasing them freely (custom drag curves or some such thing).

What percentage of shooters can even really understand and make use of custom drag curves? It is something of a tech support burden to release information to the whole community that only a few percent can use meaningfully. This may well be why neither Berger nor Hornady have made a general (free) release of their custom drag curves.

For most folks, the mathematics of differential equations is already obfuscated enough, and there is not a big difference (to their understanding of what is really happening) whether there are 3, 4, or 6 differential equations involved. The bullet companies seem to be doing their best to communicate in a way their customers can understand. Sure, they mix in marketing, but I'm not sure any are much better or much worse than the others.

I need to have a closer look at what Hornady has really done here.

But in any case, anyone who really knows how ballistic calculators work can fairly simply recreate the underlying drag table from computed trajectories. I bet you could write a spreadsheet to do it in a couple of hours. Why wait for Hornady to release their drag tables since you could do it?

We have CDM or Mach vs CD tables for over 500 bullets. That's what our raw tested data is.

 

[dcali]

Lapua releases them. Just sayin'. And you can't really reverse engineer them if their calculator is doing something weird. Plus, it's a pain.

 

[Berger.Fan222]

The problem is not in the spreadheet level computation, but to get reliable, exact data in the first place. That is REALLY hard and laborious. If it were easy, neither Applied Ballistics nor Hornady would keep the custom drag curves to themselves.

Going from custom drag tables to trajectories requires integrating the relevant differential equations.

But any knowledgeable mechanical engineer can also go from a trajectory back to the custom drag table used to compute it. Here's Hornady's custom drag table for the 750 grain A-Max (50 cal) out to 2000 yards. It took me about 15 minutes. Once one has a method down and a spreadsheet written, the drag curves can probably be reproduced in about 5 minutes each.



Mach Cd

2.6716699623 0.2493306407
2.6226856013 0.2506010154
2.574600036 0.2516126204
2.5274132662 0.2533708128
2.4806758943 0.2544549496
2.4343879202 0.2564521889
2.3885493439 0.257740752
2.3431601654 0.2594346313
2.2986697825 0.2614809897
2.2550781952 0.2632783825
2.2114866079 0.2650156967
2.1683444185 0.2672703814
2.1261010246 0.2699915172
2.0838576308 0.2719583281
2.0420636347 0.2745267726
2.0011684343 0.276004392
1.9607226317 0.2798075524
1.920276829 0.2836896165
1.8802804242 0.2865823705
1.841182815 0.2891787939
1.8020852058 0.2927461575
1.7629875966 0.2963490374
1.724788783 0.2996687497
1.6870393672 0.3028271858
1.6497393493 0.3070061345
1.6128887291 0.3098141674
1.5760381089 0.3125522121
1.5396368866 0.3177919347
1.5041344598 0.3198846216
1.4690814309 0.3246623053
1.4340284019 0.3279309133
1.3994247708 0.3325906835
1.3652705375 0.3353205484
1.331565702 0.3413788617
1.2983102642 0.3434786047
1.2655042243 0.3491931585
1.23359698 0.3523587111
1.2016897358 0.3553725661
1.1702318893 0.3627246692
1.1392234406 0.3675311731

 

[dcali]

That's not the point. Of course it can be done. But you have to make some assumptions and you wind up with rounding errors that make the resulting drag curves less than ideal. But since it can be done, that's all the more reason for Hornady to just release them.

 

[dcali]

I must say I am deeply disappointed by what I see as Applied Ballistic's polemic overreaction to the Hornady calculator. For example, 4DOF has previously been used in ballistics for the Modified Point Mass Model and is not Hornady's invention. The text in the PDF file you link to is in my view in no way up to the professionals standards your customers associate with AB. Looking at your achievements I see absolutely no reason to react in such a way.

The tone is a bit heavy handed, but I'm glad to see someone pointing out that there is a lot of technical handwaving cropping up in the industry. Hornady is by no means the worst offender (and I think you can probably chalk theirs up to trying to simplify some complex concepts), but it's got to be frustrating to watch companies make some of the claims that they do when you're trying to be transparent and educate people.

 

[Berger.Fan222]

That's not the point. Of course it can be done. But you have to make some assumptions and you wind up with rounding errors that make the resulting drag curves less than ideal. But since it can be done, that's all the more reason for Hornady to just release them.

From what I can tell, Barnes, Lapua, Sierra, Hornady, and Berger all have custom drag tables for their bullets. These drag tables are expensive and time consuming to create, and can be even more expensive and time consuming to provide technical support for. Both of these may be factors in why only Lapua (so far) has released their tables, and why Lapua only released the drag tables for a subset of their bullets.

And is Lapua really still providing custom drag tables for their bullets? The links from the accurate shooter articles on it are dead, and there is no link from the Lapua tech specs page. A working link would be helpful. It makes a lot less sense to criticize Hornady if Lapua has pulled their tables.

The rounding errors that crop up going from trajectories to custom drag curves do require a bit of engineering finesse, but rounding and instrumental errors are also present in the raw radar data. Some engineering skill should be able to reproduce Hornady's tables with comparable accuracy to their original ones. But I can't blame Hornady for not wanting their tech support lines clogged with callers who have no idea what to do with that data just to appease a small percentage of shooters who actually know how to use it.

But as a matter of fundamental fairness, calls for Hornady to release their drag tables should also include calls for Berger, Barnes, and Sierra to do the same (maybe Lapua also if theirs have been pulled).

 

[dcali]

Lapua moved their data: http://www.lapua.com/en/customer-center/qtu-lapua-edition.html

I would argue there is no point in gathering doppler data if you're not going to release it. It's exactly analogous to measuring a BC and not telling the customers. So yes, if other companies have accurate test data, I would encourage all of them to release it. None of these companies are in the business of selling ballistics calculators, so why all the secrecy? Why not release the data so customers can have confidence that they have the best data available for the bullets they want to shoot, and can use it in the calculator of their choice? Using a standard format (which Lapua has already defined), it's trivial to implement those drag tables in a point mass calculator.

 

[Berger.Fan222]

Lapua moved their data: http://www.lapua.com/en/customer-center/qtu-lapua-edition.html

I would argue there is no point in gathering doppler data if you're not going to release it. It's exactly analogous to measuring a BC and not telling the customers. So yes, if other companies have accurate test data, I would encourage all of them to release it. None of these companies are in the business of selling ballistics calculators, so why all the secrecy? Why not release the data so customers can have confidence that they have the best data available for the bullets they want to shoot, and can use it in the calculator of their choice? Using a standard format (which Lapua has already defined), it's trivial to implement those drag tables in a point mass calculator.

Most of the car companies have MPG vs. V data for their cars, but customers only get values for "city" and "highway".

Thanks for the link. Lots of interesting stuff there. I appreciate it.

I'm not sure if the companies are motivated by secrecy or concern for the tech support burden of releasing data that most of their customers will not know how to use. Any idea what Hornady spends for tech support for their US customers compared with Lapua? They seem to have a lot more full time employees.

 

[dcali]

I get it if they have data that might need some context and they don't want it out there. I don't expect them to spend resources on this for such a small number of shooters. But if they've got, good, representative data (not easy to come by, granted) of some of their bullets, it's as simple as posting it online.

I've never run one of those dopplers, but it seems like it's not all that complex a process- the computer outputs cd vs mach without any additional effort. The trick is making sure the measured shots are representative of what the consumers will see.

So I agree - sometimes what I'd like as a consumer just isn't commercially practical. But I can't help but think that we're headed that direction - where it's easy to do this sort of thing. Maybe we're not there yet.

 

[DocUSMCRetired]

I can tell you one of the reasons we don't publish it. These tables are time/work extensive. It is not cheap to do this testing. If we were to publish our complete results then other companies would steal the work. Some companies already tell their users to go to our online free calculator and pull the data to use in their apps. Imagine if we put our highly accurate, highly detailed CDM data out for all to use?

Another problem is that companies already claim they are "highly accurate" solutions when using our BC data. Which is interesting since our data was designed specifically to use in our systems. So to say that your solver is better using data developed in our system is interesting to say the least. They are way harder to use than a simple BC.

In Short:
A) Companies would steal it, and use it against us like they already do with our BC Data.
B) They would cause errors due to the complexity of this data, when they already do with stolen BC data.
C) It is very time consuming, and expensive to gather the high level of detail that we obtain. Sub 1% accuracy on many different measurements. You don't want other companies to just steal from your lab.

 

[Berger.Fan222]

In Short:
A) Companies would steal it, and use it against us like they already do with our BC Data.
B) They would cause errors due to the complexity of this data, when they already do with stolen BC data.
C) It is very time consuming, and expensive to gather the high level of detail that we obtain. Sub 1% accuracy on many different measurements. You don't want other companies to just steal from your lab.

Thanks for the comments. No doubt that capitalism is alive and well in the ballistics world, and not everyone plays fair. I cannot blame any company for keeping proprietary data to themselves when it was so expensive to create and the sharks are circling.

 

[dcali]

I can tell you one of the reasons we don't publish it. These tables are time/work extensive. It is not cheap to do this testing. If we were to publish our complete results then other companies would steal the work. Some companies already tell their users to go to our online free calculator and pull the data to use in their apps. Imagine if we put our highly accurate, highly detailed CDM data out for all to use?

Another problem is that companies already claim they are "highly accurate" solutions when using our BC data. Which is interesting since our data was designed specifically to use in our systems. So to say that your solver is better using data developed in our system is interesting to say the least. They are way harder to use than a simple BC.

In Short:
A) Companies would steal it, and use it against us like they already do with our BC Data.
B) They would cause errors due to the complexity of this data, when they already do with stolen BC data.
C) It is very time consuming, and expensive to gather the high level of detail that we obtain. Sub 1% accuracy on many different measurements. You don't want other companies to just steal from your lab.

I understand completely why you don't release your data completely (I wouldn't if I were you either). I don't understand why a bullet manufacturer wouldn't.

 

[Berger.Fan222]

I understand completely why you don't release your data completely (I wouldn't if I were you either). I don't understand why a bullet manufacturer wouldn't.

I see several possibilities. In the past, bullet manufacturers have been in the business of selling ballistic solvers. Perhaps someone involved with the Hornady effort has plans to enter that field. The data has been very expensive and time consuming to acquire. Giving it away limits future possibilities. Given that radar-generated drag tables include accurate drag measurements in the subsonic regions, Hornady or a partner could be competitive in the emerging markets for very long range trajectory calculations that require accurate subsonic drag tables.

One might also consider that the Hornady 50 cal A-MAX is in use in some military applications and owns several long distance sniper records. Hornady likely hopes for military uses for other designs. Giving away their drag tables might be shooting themselves in the foot, because potential military customers like to keep a tight lid on that level of data relating to military systems.

There is also a possibility that Hornady has some kind of non-disclosure agreement from a party involved with measuring the data. Hornady increased their capital investment and personnel rather quickly to develop the ELD and provide this new level of capability (very long range radar drag measurements). I would not be so sure they own complete rights to the data (no partner) and have full say about what gets released. Berger has only become a leader in external ballistics due to a close partnership with AB. Maybe Hornady has a partner too.

 

[Steve Blair]

In Short:
A) Companies would steal it, and use it against us like they already do with our BC Data.
B) They would cause errors due to the complexity of this data, when they already do with stolen BC data.
C) It is very time consuming, and expensive to gather the high level of detail that we obtain. Sub 1% accuracy on many different measurements. You don't want other companies to just steal from your lab.

Is it reasonable to call using that which is freely given "stolen"?

 

[Grimstod]

Is it reasonable to call using that which is freely given "stolen"?

Yes if you do not give credit for it. There are different levels of free. Taking something that is free and then turning around and selling it for $$ is steeling. IMHO