OP
OP
WrongHanded
Member
- Joined
- Jul 6, 2017
- Messages
- 4,771
To your first question: I believe that in general HSTs are an improvement over previous designs, though more so in heavy for caliber loads. The 2001 data did not include HSTs because they didn't exist yet, so my speculation there is based on gel testing comparisons and nothing more. Though not just expansion diameters, but also penetration depths or rather how quickly the bullet came to a halt. That is a long way of saying energy transfer. The 2001 book actually makes note of how the major manufacturers made changes to projectiles which actually reduced penetration depth, by increasing expansion, to far nearer the FBI's minimum of 12". I think you can see that in the Vista LE gelatin test data, when comparing some of those heavy for caliber loads to older projectile designs.
Now the .45ACP data was interesting and differed somewhat from much of the other cartridge data sets which I will explain in a moment. 9mm, .40S&W, and .357 Magnum all have the same trend in the charts. Light fast bullets and +P/+P+ loads dominant the top of the charts. Slow heavy bullets and standard pressures are towards the bottom. Though there are a few exceptions to this, particularly one 180gr .40S&W load. .38Spl also has this trend though to a lesser degree, with +P/+P+ loads at the top. Knowing what we know about .38Spl vs .357mag, we would expect this.
But .38Spl and .45acp show no real correlation in bullet weight. Unlike the other cartridges, where fast and light is at the top, these two see an even spread. It seems more about bullet design than weight. Perhaps because they are lower pressure and lower velocity loads to begin with. Maybe for some other reason.
10mm and .357SIG have limited data sets, with relative small sample sizes, though the smallest is 10 instances. And yes, fast and light is at the top and slow and heavy at the bottom. So a correlation here too.
As to your second questions: If it is based on the Strasburg Goat test, I cannot recall those numbers, but what you describe sounds correct to my memory. As for the 2001 M&S data, there were no times included with the data. But yes, FMJ was pretty bad in most cases, though into the 70% range with some cartridges. And generally the smaller diameter and lower pressure loads did not fair well. The 2001 book has an entire chapter on non-expanding projectiles and energy transfer via gelatin blocks and chronograph readings on either side of the blocks. Pretty interesting stuff. Particularly because the energy transfer percentage with increasingly powerful loads was not linear. But was still certainly measurable.
It's a very interesting book. Even without the OSS data, as there are many chapters that don't even mention it.
