Quantitative Ammunition Selection the book

[PNWTO]

I see that an example of the "formula" you referred to is not any formula from QAS, but "the four keys formula." I was actually curious about any useful terminal ballistics formula introduced in QAS -- since it was written by a fellow with a B.S. in psychology. Regarding too much time thinking about ammo and its effects -- I'll surely never come anywhere close to some who have devoted a good part of their lives to the subject, Dr. Fackler, for example. However, I am glad that he did and I find his published work useful and enjoyable read. But, to each his own.

No I idea why I'm helping necro this and I'm sure I'll regret it but I stand by my previous statement and perhaps you are reading past the simplicity of it. Doc's work is solid, as is the abundant material linked in threads and general insight at P-F. In the context of this, I have little use for "models" when we have accessible the tools that have been proven to work.

Also, in my professional wanderings, a BS in Psychology is of little meaning and should be leaned on as a vetting factor.

[QED]

No I idea why I'm helping necro this and I'm sure I'll regret it but I stand by my previous statement and perhaps you are reading past the simplicity of it. Doc's work is solid, as is the abundant material linked in threads and general insight at P-F. In the context of this, I have little use for "models" when we have accessible the tools that have been proven to work.

Also, in my professional wanderings, a BS in Psychology is of little meaning and should be leaned on as a vetting factor.

Models can be quite useful depending on who is doing the modeling. When it comes to modeling bullet penetration I'll lean on a guy with advanced engineering degree from M.I.T. and experience in rocket science, D. MacPherson, instead of a guy with a B.S. in psychology, C. Schwartz, the author of QAS. However, QAS may have some elements of humor, unintended of course.

[PNWTO]

@QED, sounds dandy

[willie]

These models are not new, but I've never seen one that correlated with expansion and penetration. Any way you cut the pie, you will always have this truism: within calibers some ammo products are much more effective than others. Doc's summary takes the guess work out of any ammo effectiveness discussion.

[QED]

These models are not new, but I've never seen one that correlated with expansion and penetration. Any way you cut the pie, you will always have this truism: within calibers some ammo products are much more effective than others. Doc's summary takes the guess work out of any ammo effectiveness discussion.

Have you read or applied MacPherson's treatise on bullet penetration? In the likely event that you haven't, his penetration model correlates just fine with bullet expansion and penetration.

[willie]

No. As stated, I never read one that correlated these variables in terms of effectiveness. I look forward to studying MacPherson's model. Thank you for bringing it to our attention.

[QED]

No. As stated, I never read one that correlated these variables in terms of effectiveness. I look forward to studying MacPherson's model. Thank you for bringing it to our attention.

MacPherson's book is very well done and provides quite useful analysis of dynamics involved in bullet penetration, without requiring a Ph.D. in physics for complete understanding.

[ArgentFix]

But surely being at least an undergraduate in physics permits a certain level of quantitative objectiveness unavailable to the layman when evaluating the models of D. MacPherson and Dr. Fackler.

[QED]

But surely being at least an undergraduate in physics permits a certain level of quantitative objectiveness unavailable to the layman when evaluating the models of D. MacPherson and Dr. Fackler.

Surely, it wouldn't be a detriment whatsoever and it undoubtedly would facilitate understanding; however, college level courses in physics are not a prerequisite for a thorough understanding of the material in that book -- at least for all practical purposes.

[TexasViking]

Okay, I think we can all agree that one's academic credentials are useless in a defense scenario while the stakes can be mortal. So, if I may, I'd like to confess how I felt about QAS before I committed to an objective study of it. I can even remember jokingly quoting the Mel Brooks comedy Spaceballs line: May the Schwartz be with you! Today I’m glad to know the Schwartz! I was a skeptic. . Now I'm mostly retired at 65 and I didn't degree in engineering. Our state 2-year tech college worked well enough for what I was most interested in: Design Drafting. College Algebra and Trigonometry were the math requirements. My personal study of physics - as it pertains to ballistics has mostly come from reloading manuals like the Lyman 46th edition and some logically reasoned articles from those whose opinion I respected from LE Officers to professional hunters. And I read a good many articles on handloading and ballistics starting about five years prior to making my first .41 Magnum handload 36 years ago: the most practical handgun magnum, IMO. And maybe it just didn't have the credentials to blow a Scotsman’s kilt up. From a practical standpoint, it has proven capable of harvesting any game animal that the .44 Magnum is practically capable of, provided the shooter is up to the task, maybe with some actual handloading experience, and with less recoil, greater energy in many cases, along with a greater ability to penetrate by virtue of it's smaller diameter in relation to length. A subject many of us know as sectional density. And in .44 Magnum size revolvers like the S&W M57, recoil wasn't much more objectionable than the .357 Magnum. A cartridge ignored by too many “experts,” IMO. I’ve also been loading the 9 x 19mm for more years than the pink elephant known as +P has been in existence. Now, regrettably, used as a marketing tool. I guess people have different perspectives on safety. Inaccuracy has no place in mine.
Because of my occupation I became necessarily involved in hydraulics, with a short but intense trained in a manufacturer's course where its original instructor wrote the most respected work in the industry. But he did more than that without having the engineering degree that you might expect. Of his own volition, he devised a mathematical calculation, that with some basic ability with a scientific calculator, you could determine the friction loss for water, at any given pressure or flow volume, for almost every common type of piping in existence. This enabled me to do with a calculator in just a few seconds, what it required engineers - at that time - to do with their charts and graphs in reference books requiring a good many minutes.
Fortunately for me, I was getting acclimated in my design career commensurate to my pursuit of handloading. And with all due respect to Mr. Schwartz, I was water testing before water testing became cool! And it is COOL! I was also consulting - as a designer - to engineering firms who had been contracted for projects, of my specific expertise, and with varying results. And I'll gladly admit that I my water testing wasn’t great science compared to QAS. I did, however, apply a good amount of common sense and practical experience into the mix. I believe in what my own eyes tell me before I allow myself to become swayed by someone until their opinion goes from hypothesis until proven empirically; not theoretically.