MY bad, I thought I had read they were claiming a .370 G7. That said,
I'm not dismissing your field experiences but at the same time I would be VERY surprised that the BJ 131 BC is greater than the Berger 6.5 140 Hybrid
I don't mind the skepticism or the generalities of these types of statements. We get them a lot.
As most of the guys know, we spent a couple of years looking at nearly every single modern projectile from the efficiency of what might as well be the G7 Standard, the Lapua Scenar and upwards in efficiency to the latest and greatest.
We looked at boat tail length, boat tail diameter, boat tail angle, bearing surface length, hybrid section lengths, nose lengths, ogive radius, and the ratios of all these elements together.
Why are some bullets under-performers when everything seems pretty much right? Why do a handful of bullets seem to work just that much better? There are very specific reasons once you line them all up and look closely.
When you review that data it's quite obvious that the designer at JLK really pushed a few big things forward in the ballistics world and did not get as much credit as due.
Other custom makers like Hoover and a few small shops really hit homeruns with way-ahead-of-their-time form factors, and due to the nature of their production capacity these things never really made it to the market in a way the average shooter was aware of their advantages.
I love the 140 hybrid and the 180 hybrid and the 230 hybrid. BUT it's not that hard to out-design them ballistically.
I cannot speak for Berger and their design team, but those bullets represent a very balanced and well shooting family of designs that has stood the test of time. I know they know how to make more aggressive bullets, but their product line was superior at the point of entry and still claims many titles and shooters' loyalties today despite more efficient designs.
To push the envelope on any design parameter you enter into trade-offs. I won't get too in depth on the how and why we decided to push X% this far in one design element and cut Y% to just there, but it should be pretty clear the combination of pushing the envelop closer to the edge but not too far worked out pretty well.
Our next bullet designed for hunters follows the same philosophy and will outrun this 131 ACE in same-parent-case comparisons to 1000-1100 yards and hit a bit harder on the way out there too!
It was designed for HUNTERS but the side effects of such an efficient design will benefit midrange target shooters and a lot of BR, x47, and Creed case users in competitions.