Michael,
ABM is in its early stages of operational development. More data will become available in time. It is our plan to provide as much technical information on our website as possible. Some of it is there already. Please see the velocity data provided on the ABM cartridge linked below.
308 Winchester 155.5gr Berger Match Fullbore Target
The BC data for the bullets are available through many sources. I'm sure you are aware that the BC of a bullet doesn't change due to load.
Well, there was that .338 bullet with the nose slump problem and the need to revise the published BCs.
Berger Bulletin » Update Regarding the .338 Hybrids
http://www.longrangehunting.com/for...er-bullets-regarding-338-hybrid-bullet-57561/
Maybe you meant trajectory data? We do list velocity and energy loss over a range up to 400 yards.
No, I meant BC and velocity data, including data on the variations in BC and velocity. As I'm sure you know, small variations in these are very important for long range accuracy.
Also, I hope ABM takes more care regarding carelessly repeating unverified BCs from bullet manufacturers. I think almost every company that reloads Nosler bullets simply repeats Nosler's BCs and trajectory computations based on Nosler's BCs even though almost everyone in the industry knows their BCs are exaggerated on several model lines. I've heard some talk among attorneys regarding a class action lawsuit against ammo companies who are careless with their BC specs, and I'd hate to see Berger or a new ammo company loading Bergers hit with this kind of thing.
Regarding velocity, our goal is consistency from lot to lot rather than to achieve some "superformance" type results. There is no compromise in such things. As you've suggested, to get more velocity you have to have more pressure.
Agreed. Consistent velocity and BC and accuracy at moderate (SAAMI spec) pressures is advised. If a specific customer (DoD, etc.) is willing to knowingly accept higher pressures to get higher velocities, then full disclosure is needed about the pressure issues.
I tend to think that you are bitter about Bryan's level of recognized success in the field of ballistics as compared to yours and use every opportunity to be critical of his work. I could be wrong.
I don't understand why you would think I'm picking on Bryan or Berger. I've been an equal opportunity offender and have pointed out many more exaggerations and inaccuracies and product flaws in material from ATK, Nosler, Hodgdon, Hornady, Remington, and some of the smaller vendors too. Accuracy in ballistics specs and advertised performance is important to my colleagues and I. My colleagues and I have often cited Bryan's books and papers favorably in areas where we are in agreement. But when have either a sound theoretical or empirical basis (or both) for calling another scientist's published findings into question, we view doing so as an essential part of the scientific method.
Since Bryan became the ballistics guru for Berger, his BC measurements of Berger bullets really cannot be considered "independent" like they can when he publishes measurements of bullets from Nosler, Hornady, Sierra, etc. Other than updating my CV once in a while, I don't give too much though to my recognized accomplishments in ballistics. I publish a lot of papers, attend conferences, get asked to consult on matters by DoD contractors, labs and legal teams, and get asked to peer-review more scholarly papers than anyone else I know.
If you could provide any basis in fact for your assumptions I might take you more seriously. I understand that being critical of scientific findings is how the truth is revealed. Is this your goal?
My goal is improved science.
Bryan himself has published a paper on the well known shot to shot BC variations of open tipped rifle bullets along with his findings regarding how trimming and pointing impact BC and BC consistency. We've got reams of our own BC data also showing that plastic tipped bullets (eps. Hornady AMAX and VMAX) have much better shot to shot BC consistency than open tipped bullets. The data in Bryan's book shows this also.
We have also independently measured BCs of a number of Berger bullets and found that in most cases, Berger's numbers are overly optimistic.
Some Air Force colleagues and I published our findings at DTIC back in 2012. Our published findings included G1 BC determinations of the following bullets which differed significantly from Berger's publish claims:
.308 155.5 gr FBBT AF G1BC: 0.406 Berger G1BC: 0.464
.308 168 gr VLD AF G1BC: 0.421 Berger G1BC: 0.473
.224 62 gr FB AF G1BC: 0.245 Berger G1BC: 0.291
Since that was published, a colleague and I measured the BC of the 52 grain FB Varming bullet and obtained:
.224 52 gr FB C&C G1BC: 0.179 Berger G1BC: 0.197
Our BC measurement methods have been validated by comparison with an independent acoustic method (different from Bryan's acoustic method) and are accurate to 1% unless the bullet itself has shot to shot variations in BC.
We are not ready to release our results yet on Berger's 230 grain .308 bullets, but given the documented history of the .338 debacle and the bullets we've tested previously not meeting their specs, is anyone really going to be surprised if these extraordinary BC claims are not validated by independent sources?
I would recommend that ABM get independent verification of Berger BCs before repeating Berger's marketing claims. And we did measure the BC of the 155.5 Fullbore in two separate rifles: one Rem 700 ADL with 1 in 12" twist, and also in another Rem 700 with the bull 5R milspec barrel. The separate measurements yielded G1BCs of 0.409 and 0.406.
