Which Published Berger BCs Are From Predictions Rather than Measurements?

[6BRinNZ]

This thread presents as an integrity attack on Eric, Bryan and Berger in general, with an improved understanding of the BC of a limited selection of bullets as the vehicle to attack from.

Do you think anyone has learned that if you misrepresent your product marketing specs, someone might call you out on it?

Not a bad lesson for DoD contractors and those who aspire to multi-million dollar ammo contracts.

Sure - you had a choice to do it in a positive fashion by supplying improved information about BCs and allowing natural customer interest to drive change (if thats what they wanted). Instead you are making it about marketing machines and honesty/integrity with ballistic information as an aside, which simply comes across as ulterior motive.

Enough said, hopefully this thread fades away and gets no more air time.

 

[Michael Courtney]

Sure - you had a choice to do it in a positive fashion by supplying improved information about BCs and allowing natural customer interest to drive change (if thats what they wanted).

A couple days before I posted here, both Bryan and Eric had opportunities to directly answer my question whether the BCs of the 62 and 52 grain varmint bullets had actually been measured. They chose to avoid answering the question directly.

I did more background, realized most of the BCs of the flat base match and varmint bullets had not really been measured, and persisted until I got a more direct answer regarding where the marketing specs had come from.

Instead you are making it about marketing machines and honesty/integrity with ballistic information as an aside, which simply comes across as ulterior motive.

Eric made the discussion about marketing when he claimed Berger was committed to publishing accurate BCs based on firing tests rather than numbers inflated for marketing.

Enough said, hopefully this thread fades away and gets no more air time.

I would suppose Berger does also. Remington, Nosler, Hodgdon, ATK, and some other vendors probably hope some of my other discussions fade quickly with little notice too.

7000+ views so far on the various forums. We're still considering whether to publish a scholarly paper that will get thousands of downloads each month for the next decade or so. If Berger makes it clear on their web site that they did not measure the flat base and varmint bullets, and the accuracy of these BCs may only be 10%, we probably won't have to go that route.

I keep hearing talk of class action lawsuits against bullet makers who are exaggerating their BCs. When this storm hits, the companies that responded by revising their specs will be happy they did.

 

[Keith Glasscock]

Nothing scholarly at all about that route. For that matter, not ethical in the least either.

Good work. Maybe now I can get bullets more easily.

By the way, the view count thing is tacky. I'm sure it serves your need for attention, but comes off as a bit pathetic.

Enjoy the attention.

 

[Michael Courtney]

Nothing scholarly at all about that route. For that matter, not ethical in the least either.

Calling out a vendor on inaccurate product specs is less ethical than publishing the inaccurate specs in the first place?

Would you feel the same way of the vendor sold ballistic vests? Cars? Building materials?

 

[Bryan Litz Ballistics]

Sure - you had a choice to do it in a positive fashion by supplying improved information about BCs and allowing natural customer interest to drive change (if thats what they wanted).

6BRinNZ,

Michael HAS published works on BC's for many brands. Click here to see it: http://www.dtic.mil/dtic/tr/fulltext/u2/a554683.pdf

Just read the very first paragraph.

So he publishes a paper called: "Comparing Advertised Ballistic Coefficients with Independent Measurements", in which HE DIDN'T FIRE A SINGLE SHOT. It gets better if your read on. Spoiler; the "Independent Measurements" are MY BC's!

So when the US Air Force is paying him to write these fancy peer reviewed papers, my data is good. But now that he's on his own, he's got to tear me and Berger down.

[quote author=Micheal Courtney]7000+ views so far on the various forums. We're still considering whether to publish a scholarly paper that will get thousands of downloads each month for the next decade or so. If Berger makes it clear on their web site that they did not measure the flat base and varmint bullets, and the accuracy of these BCs may only be 10%, we probably won't have to go that route.[/quote]

Is that a threat?

You do realize that the 7000+ views is not a measure of your success; it's the amount of people who've seen you make an a$$ of yourself. The more the better IMO. The quicker people can identify you for what you really are, the better off we'll all be.

PLEASE publish one of your 'scholarly papers' to further spread the already common knowledge of your reputation as a fraud.

Of course this isn't a new thing for you at all. It goes back to your college days. I think you might be one of those people that enjoys pain: http://tech.mit.edu/V110/N50/jackso.50o.html

 

[Michael Courtney]

PLEASE publish one of your 'scholarly papers' to further spread the already common knowledge of your reputation as a fraud.

Please clarify what fraud you've found in the initial post or the attachment:

Which Published Berger BCs Are From Predictions Rather than Measurements?

Both Eric Stecker and Bryan Litz give the definite impression that Berger's BCs published since 2009 or so are the result of Bryan's careful and well documented BC measurement system (using an acoustic method over 600 yards) rather than the output from any kind of predictive model.

For example, in a blog post dated 30 January 2009, Eric Stecker wrote:

A few months ago Bryan became Berger Bullet’s full time Chief Ballistician. Since Bryan has the ability to accurately measure fired BCs with +/- 1% repeatability and since we are committed to providing shooters with the best product and data it was an obvious and simple decision to update our published BCs to Bryan’s fired numbers. (Why Our BC Numbers Have Changed (Been Corrected) | Berger Bullets Blog )

Bryan Litz has written:

The first thing I did when I started working for Berger was to reassess all the advertised BC’s (which were based on computer predictions) to the actual measurements I took from live fire and averaged over long range. This resulted in an average 3% to 5% reduction in Bergers [sic] advertised numbers. I also introduced the idea of using G7 BC’s [sic] to minimize velocity effects.

The effect of the claim to have measured ALL of Berger's advertised ballistic coefficients is to give customers the impression that the likely accuracy level corresponds to the 1% or so claimed accuracy of the Litz measurement system rather than much less accurate predictive models, such as the McDrag model developed by Bob McCoy at BRL or the Litz predictive model published as equation 17.1 in his 2009 book, Applied Ballistics for Long Range Shooting.

The attached figure shows changes in Berger's advertised ballistic coefficients between 20 October 2008 (when Berger was using a predictive model attributed to Bill Davis for their BCs) and 14 April 2010 (after Berger had purportedly updated their advertised BCs to "Bryan's fired numbers" (to quote Eric Stecker). In total (counting bullets with the same shape and BC only once), the BCs of 66 bullets were updated, and the percent differences in these new BCs are shown as red squares in the graph. However, comparing with Bryan's book, Applied Ballistics for Long Range Shooting (the blue Xs) shows only 35 of the new BCs can be attributed to Bryan's experimental measurements.

Where did the new BCs for the other 31 bullets come from? The most plausible explanation seems to be that Berger re-calculated these BCs based on an "improved" predictive model (or a similar predictive model) based on equation 17.1 of Bryan's 2009 book. This model purports to have a 95% confidence level of 4.2% for boat tail bullets, but predictions for flat base bullets would likely be much less accurate.

One reason I lean toward this possibility is because the 115 grain .257 VLD had its BC advertised at 0.479 at the Berger site on 6 February 2009, and I received two boxes of these bullets with this BC printed on them at about that time. However, in Bryan's 2009 book and later on the Berger site, the BC was revised to 0.466. When I asked him about these differences, Bryan explained that the BC value of 0.479 had been based on a predictive model and used temporarily until the BC could actually be measured with his method. I think several other bullets (like the 87 grain .257 bullet) whose advertised BCs were changed twice between 10/26/2008 and 2/6/2009 and 4/14/2010 may have also had the intermediate value based on a predictive model later changed to a model based on measurement. It is certainly possible that all 66 bullets were updated based on actual measured BCs, but it is also possible that some bullet BCs were updated based on a predictive model and have still not been updated based on real measurement results.

It may be notable that while most of the bullets whose revised BCs seem to be based on a predictive model have BC adjustments under 5%, 16 of the 35 or 36 bullets that seem to be based in actual firing measurements have been adjusted downward by over 5%. Other than a 17 cal bullet, the biggest downward adjustments were the 87 grain .257 (-15.85%), the 115 grain .257 (-10.9%), and the 105 grain .243 VLD (-11.33%).

Now this may seem like so much ancient history, except that, for the bullets still in the Berger catalog, nearly all of the 30-31 bullets whose revised BC seems more likely based on a predictive model than actual firing measurements have had their advertised BCs unchanged since 14 April 2010.

In light of these concerns, I think Berger owes the shooting community some quick and honest answers regarding which of their currently advertised BCs have actually been measured by live firing and which are attributable to a less accurate predictive model. After all, Eric Stecker is on record as saying:

A BC is not a marketing tool and should not be inflated (intentionally or by using inaccurate means to calculate BC) for the purposes of selling more bullets. Some will say that inflating BC is smart business but frankly, we do not agree. A BC is an important number with physical meaning that’s used to calculate the trajectory of a given bullet which enables shooters to reliably engage targets at long range. The BC should allow a shooter to hit their aim point each and every time. There are many factors that influence the location of bullet impact but an accurate BC number is an essential component in achieving the most successful shooting experience no matter which brand you shoot. The bullet makers owe it to the shooters to provide them with truly accurate information about the performance of their product and that’s what we’re committed to.

When Berger was asked directly in 2014 whether the BCs of two specific varmint bullets had been measured directly or resulted from a predictive model, Eric Stecker hinted but dod not answer directly:

I won't say that we don't have a few FB bullets that need closer review but the varmint bullets are not our priority. Anything with a BT has been thoughroly tested.

Links to past Berger BC specs:


Berger Bullets - All Bullets

Berger Bullets - All Bullets

Berger Bullets

If my material is accurate, how can you honestly say it is fraudulent?

 

[Michael Courtney]

Since different parties are suggesting we have unfairly singled out Berger and Bryan brought up a paper where we give Nosler a pretty hard time, maybe a quote from that paper is appropriate:

To further investigate the possibility that Nosler is generating their BCs for marketing purposes rather than to best inform the shooter regarding ballistic performance, the BCs of the Accubond line were compared with the Ballistic Tip line in cases where there was a Ballistic Tip bullet in the same weight and caliber listed in the Nosler Reloading Manual #4. There were seven Ballistic Tip bullets listed in the reloading manual of the same weight and diameter of the Accubond bullets which were introduced several years later. It is notable that 6 of the 7 Accubonds list exactly the same BCs (to three significant digits) in spite of having different boat tail angles and ogives than their Ballistic Tip counterparts. What is the probability that six of the seven Accubond bullets with Ballistic Tip counterparts were actually tested to have identical BCs? In contrast, what is the probability that Nosler decided simply to list the BCs of the Accubond as equal or greater than the Ballistic Tips for the Accubonds with Ballistic Tips in the same diameter and weight regardless of what was actually measured? The average BC to SD ratio for Accubonds with Ballistic Tip analogues is 1.879 (five of seven above 1.9); in contrast, the average BC to SD ratio for Accubonds in weights unique to that design is the more humble 1.788 (only two of 15 above 1.9). One wonders if Nosler felt free to advertise more accurate BCs for Accubonds without Ballistic Tips to which to compare them.

 

[Bryan Litz Ballistics]

Again, changing subject. The ole' "On to Child Sacrafice" routine! http://tech.mit.edu/V110/N50/jackso.50o.html

I didn't say you were a fraud because of one single post, it's the stuff that's come up along the way.

You claim to be an objective scientist, yet here you are on an obviously bias smear campaign across multiple forums attacking a single bullet company.

You were paid by the US Air Force Academy (with tax dollars) to study varmint bullets and potato guns.

You were paid by the US Air Force Academy (with tax dollars) to publish a paper titled "Comparing Advertised Ballistic Coefficients with Independent Measurements" in which you didn't fire a single shot, and in which you used my test data.

Now you might be able to argue that there's no fraud in there, but I see it differently.

Eric answered your original question over a week ago.

Berger has placed a caveat on the website stating that not all FB bullets BC's are directly measured.

What more do you want?

More attention?

Waiting for someone to congratulate you?

What?

 

[Bryan Litz Ballistics]

Since different parties are suggesting we have unfairly singled out Berger and Bryan brought up a paper where we give Nosler a pretty hard time, maybe a quote from that paper is appropriate:

Until you launch a public smear campaign across multiple forums, it's hardly the same thing.

I don't know any shooters who read your 'scholarly papers', and take them seriously.

Tell us again how lubricant isn't slippery: http://www.dtic.mil/dtic/tr/fulltext/u2/a568594.pdf

 

[Michael Courtney]

HE DIDN'T FIRE A SINGLE SHOT.

Our research was subject to some earlier criticisms that we were wasting taxpayers money. Here, we figured out how to be much more efficient about addressing the question of accuracy of marketing specs, so we are criticized for an approach minimizing costs and efforts.

It is very common in scholarly work for one research group to reassess and analyze available data from other groups. The Mauna Loa CO2 data has been re-analyzed and re-published dozens of times, as have many other available data sets. This is part of how science works. When we can acquire data that provides insights into interesting questions without needing funding sources to pay for additional experiments, we move forward with that approach. Re-analyzing and re-assessing available data was very much complementary to our original experimental work when I was at the Air Force.

There is an old saying that an hour in the library can save a month in the lab, and one of my recognized strengths among colleagues is a familiarity with the open literature and available data sets.

 

[Lbart]

Dude, seriously...just give it a rest. You're simply digging the hole deeper for yourself with every post. No one with any knowledge is buying into your flagrant attempt to discredit Bryan, Eric, or Berger Bullets. What part of that don't you get?

My goal was improved honesty and accuracy in product specs, and progress has been made in that direction.

It seems like some posters are asking questions in good faith and seem interested in an ongoing discussion. It would seem rude for me to simply stop replying to direct questions when they are asked. Thousands of views and dozens of replies suggest interest in the discussion. Many colleagues and peers have expressed appreciation for my participation in this conversation.

My god Michael your comments are just like the sound bites I hear on the news and read in the papers. You should give up posting on this site and go into politics. You would fit right in.

Regarding the thousands of views and dozens of replies you mentioned, as of the time of your post I quoted there were 78 posts on the thread. Twenty six of those were your rants, 45 were comments favoring Berger, 2 or 3 could be interpreted to be anti Berger and the other 4 were questions, etc.

Like a politician your thousands of views are double counted votes since most people have looked at this thread a good number of times to see what cockeye ideas you are going to quote next to bad mouth a great American company. Crawl back into your Ivy Tower and leave us shooters alone please.

 

[Bryan Litz Ballistics]

HE DIDN'T FIRE A SINGLE SHOT.

Our research was subject to some earlier criticisms that we were wasting taxpayers money. Here, we figured out how to be much more efficient about addressing the question of accuracy of marketing specs, so we are criticized for an approach minimizing costs and efforts.

My real criticism lies with the way you manipulated my measured BC's by using them to calculate remaining velocity at 200 yards using JBM, then, using JBM, calculating what BC would produce that remaining velocity. One can only wonder why this kind of laundering was necessary. Possibly because reprinting copyrighted material for profit is not OK without permission from the author. Whatever the reason for this misrepresentation of my numbers, it didn't do anyone any good to talk about G1 BC's at some arbitrary velocity range spanning 200 yards.

It is very common in scholarly work for one research group to reassess and analyze available data from other groups.

Maybe in the circles you publish in, but along the way you really should provide some original work of your own.

There is an old saying that an hour in the library can save a month in the lab, and one of my recognized strengths among colleagues is a familiarity with the open literature and available data sets.

Good for you. One of my 'recognized strengths' among shooters is the amount of time I spend in the lab producing original work. And how familiar are you with the open literature in your field? Just yesterday you were made aware of a book containing several chapters from a foremost expert in the field of wind measurement; a field you endeavored to gain govt funding for without even knowing the state of the art.

 

[Michael Courtney]

You were paid by the US Air Force Academy (with tax dollars) to study varmint bullets and potato guns.

The cost to USAFA was under $1000 for each paper we published. The Naval Academy has published more papers on potato guns than we have, and USAFA was happy that we could make a bit of a splash in the educational journals with the occasional piece making the learning of physics fun. This paper garnered positive press from the Smithsonian Magazine and MIT Technology Review also. That paper also made it clear that a very similar and inexpensive technique can be used to study fuel-air combustion rates over a range of pressures - something that the Air Force has been spending millions on.

Our main interest in varmint bullets was inspired by Don Miller's desire to develop more accurate stability formulas for plastic tipped and open tipped bullets. Measuring the BCs was a necessary baseline for testing the improved stability formulas. As you know, DoD is fielding lots of open tipped bullets lately, and there was an in interest in being able to accurately determine whether a bullet would stabilize under certain conditions without the expense and time of running PRODAS.

You may not know that the Air Force still has many thousands of M16 A1 rifles it uses in training. We were able to determine that the 62 grain BFB is not an acceptable ballistic training substitute for the M855 because it's BC is too low. Our work in stability revealed that the 62 grain M855 will stabilize in the slow twist rifles above a certain altitude (including USAFA), so that this bullet can be used in training.

Eric answered your original question over a week ago.

Eric avoided the question by saying that varmint bullets were not the priority.

He gave no clear indication which bullets had not been measured or how the BCs had been determined. He also left vague whether the flat base match bullets has BCs determined via firing.

Berger has placed a caveat on the website stating that not all FB bullets BC's are directly measured.

What more do you want?

I've been clear that the caveat is buried deep in a faq and still hidden from view from the main BC specs. When a customer clicks the ? by the main BC listing on the varmint bullet page (http://www.bergerbullets.com/products/varmint-bullets/ ), she sees:

The BC's of Berger bullets are based on carefully controlled test firing. The BC's established by this method are accurate to within +/- 1%, whereas BC's predicted by computer programs can have as much as +/- 10% error. All BC's reported for Berger bullets are corrected to the ICAO Atmosphere.

I think a clarification is needed here also.

 

[Michael Courtney]

Just yesterday you were made aware of a book containing several chapters from a foremost expert in the field of wind measurement; a field you endeavored to gain govt funding for without even knowing the state of the art.

When did that book start shipping? July? I'll have it read by the end of this year.

And for clarification, we have never endeavored to gain government funding for studying wind measurement or wind drift. We never submitted a grant application. We never asked the chain of command permission to travel or pursue wind drift projects as part of our duties.

Several years ago, we used some private money to put together an array of vane mounted Kestrels and design an experiment. After working with the Kestrels and collecting some pilot data, we decided the experimental design we liked better was one simultaneously firing bullets with the same BCs and the same velocity and compare drift to see if drift of bullets with widely different masses really have the same wind drift as predicted by MPM models. This design allows testing the MPM model independently of the accuracy of wind measurements.

 

[Bryan Litz Ballistics]

Just yesterday you were made aware of a book containing several chapters from a foremost expert in the field of wind measurement; a field you endeavored to gain govt funding for without even knowing the state of the art.

When did that book start shipping? July? I'll have it read by the end of this year.

And you're the one your collegues look to for research. Nice.

And for clarification, we have never endeavored to gain government funding for studying wind measurement or wind drift. We never submitted a grant application. We never asked the chain of command permission to travel or pursue wind drift projects as part of our duties.

So, I searched my emails to make sure I remembered it right. Here's what I found:

From: Michael Courtney <Michael_Courtney@alum.mit.edu>
To: Bryan Litz <bsl135@yahoo.com>
Sent: Tuesday, November 1, 2011 6:44 PM
Subject: Advice on experimental design to test wind drift

Bryan,

We're about to secure funding and approvals for an experiment to test wind drift formulas. Initial experiment at 600 yards, with possible extension to 1000 yards.

Two main comparisons:

1. Do bullets with same BC and muzzle velocity fired in the same direction at the same time experience the same wind drift (independent of mass and caliber)?

2. Are formulas predicting wind drift relatively accurate?

So, who were you 'about to secure funding' from?

And this brings us back to the discussion about you 'validating' the equations of motion that we discussed on Snipers Hide. For those interested, the conversation pretty much picks up on page 2 of this thread: http://forum.snipershide.com/range-report-exterior-ballistics/267512-published-berger-bcs-predictions-rather-than-measurements-2.html

Michael,

I'm about thru wasting my time arguing with you.

Readers, I promise to continue providing the best information I can on ballistics. I'm sure Michael will continue doing what he does.

-Bryan

 

[savagedasher]

Just yesterday you were made aware of a book containing several chapters from a foremost expert in the field of wind measurement; a field you endeavored to gain govt funding for without even knowing the state of the art.

Will you list the products your involved in. I would like to know so I don't buy them.
I will keep shooting Berger Bullets. I don't care what the box says the BC is the proof is the holes in the paper. Larry

When did that book start shipping? July? I'll have it read by the end of this year.

And for clarification, we have never endeavored to gain government funding for studying wind measurement or wind drift. We never submitted a grant application. We never asked the chain of command permission to travel or pursue wind drift projects as part of our duties.

Several years ago, we used some private money to put together an array of vane mounted Kestrels and design an experiment. After working with the Kestrels and collecting some pilot data, we decided the experimental design we liked better was one simultaneously firing bullets with the same BCs and the same velocity and compare drift to see if drift of bullets with widely different masses really have the same wind drift as predicted by MPM models. This design allows testing the MPM model independently of the accuracy of wind measurements.

 

[MrMajestic]

All of this intellectual debating(bickering ;D) is good stuff! No where did I see Michael advise not to buy Berger Bullets and I might add they are some of the most accurate production bullets I've fired.
I certainly don't understand it all but have gleaned some. Thank you both.

 

[Michael Courtney]

And for clarification, we have never endeavored to gain government funding for studying wind measurement or wind drift. We never submitted a grant application. We never asked the chain of command permission to travel or pursue wind drift projects as part of our duties.

So, I searched my emails to make sure I remembered it right. Here's what I found:

From: Michael Courtney <Michael_Courtney@alum.mit.edu>
To: Bryan Litz <bsl135@yahoo.com>
Sent: Tuesday, November 1, 2011 6:44 PM
Subject: Advice on experimental design to test wind drift

Bryan,

We're about to secure funding and approvals for an experiment to test wind drift formulas. Initial experiment at 600 yards, with possible extension to 1000 yards.

Two main comparisons:

1. Do bullets with same BC and muzzle velocity fired in the same direction at the same time experience the same wind drift (independent of mass and caliber)?

2. Are formulas predicting wind drift relatively accurate?

So, who were you 'about to secure funding' from?

As I wrote above, our wind drift work to date has been done with private funding. As usual, our work is under non-disclosure agreement until the stakeholders have all given approval for public release. A lot of privately funded work is not published. You keep criticizing us for wasting taxpayer money, but our research is mostly privately funded, and the work done with taxpayer money was much more cost effective than comparable work by others.

Too bad you jumped to the conclusion that this was a government project, and even posted a private email exchange to try and prove it.

On the other hand, knowing that we were working on that project since 2011, why have you kept asserting that we have no data to doubt the MPM wind drift predictions?

 

[Michael Courtney]

All of this intellectual debating(bickering ;D) is good stuff! No where did I see Michael advise not to buy Berger Bullets and I might add they are some of the most accurate production bullets I've fired.
I certainly don't understand it all but have gleaned some. Thank you both.

Agreed.

If you can find them, Berger bullets have outstanding accuracy. My intent has been to increase the accuracy of product specs, not to hurt the sales of Berger bullets.

Go and buy some Berger bullets today!

 

[Grimstod]

Michael,

This is a Berger Varmint Bullet:

Notice the flat base and wide open tip.

That's because varmint bullets are designed for two things: Precision and Terminal effect.

Measuring BC down to the 1% is not a high priority for varmint bullets

Everyone else seems to understand this except you; with the PHD from MIT.

For bullets which are fired at long range and designed for high external performance, that external performance is measured and represented accurately. We've even caveated our statement now acknowledging that some flat base BC's are predicted and not measured.

When you choose to attack one brand on multiple forums and say nothing about the others, that's not customer advocacy, that's called bias.

I think you have a personal problem with me and/or Berger, it's the only explanation for your continued rant about irrelevant minutia.

We measured this bullet's BC as 0.245, 18.8% lower than the revised spec. The Berger 52 grain flat base varmint BC was revised from 0.207 to 0.197, which is -4.83%. We measured this bullet's BC to be 0.179, 15.6% below the original spec and 9.1% below the revised spec.

And frankly, I don't believe any measurements you're presenting on our bullets after you've demonstrated such a strong bias against this single brand.

I thought this place was all about precision and accuracy? What your saying is its close enough? Doesn't sound like a Accurateshooter post to me. Sorry I just had to cause severe others have said this to me.