Morning, Steve,
most manufacturers tend to be a bit cagey about what they consider proprietary information. And yes, most purchase and evaluate those of the competition. I'm sure the straight dope will come out once more people have had some experience with them.
A bullet has to have some mass to achieve a high BC; it can't be done via shape alone. While these bullets may indeed have a very streamlined shape, When using a less dense material, say solid copper as opposed to the more conventional lead-cored, gilding metal jacketed design, the result has to be a longer bullet to get to the same SD, and at some point that length is going to become a problem (twist rates & stability) in and of itself. The other way to go here is to use a much denser material to achieve the high SD, and resulting increase in BC. PRL did this some years back when they came out with a polymer-cored 87 grain .224" match bullet that looked almost exactly the same as a 69 grain HPBT match bullet. Very high SD, significant improvement in BC. They were also extremely expensive and seemed to have accuracy and consistency (lot to lot) problems. I haven't seen anyone using these in years now, but you get the drift.
The problem here is that we run into a very stubborn set of physics. They don't change, they don't bend, and whatever advances can be made tend to be incremental. Working on all of these, but a healthy dose of skepticism is always warranted.
I'd have to disagree with you a bit about the progress in this field, too. In my opinion, the only truly significant (world changing) developments in the past 150 years in this field were, 1) the development of smokeless propellant; allowed the development of several entirely new action/operation systems, 2) the development of the gilding metal jacketed bullet; allowed significantly improved pressures and velocities, and 3) the epiphany of just how much more aerodynamic a pointed bullet was over the standrad of the time, a heavy-weight round nose. This last revolutionized military tactics worldwide, every bit as much as the development of nuclear weapons did 50 years later. Everything else has been relatively small improvments made possible by better and more precise manufacturing, better materials, etc.. Long, slow process of evolution at work here.
Kevin Thomas
Berger Bullets