I don't disagree. But the problem is, and was, what was being read, was not learned papers, but thinly disguised advertising in the popular in print gun press. Dr. Fackler rails against this in one of his papers. Police departments, even the military, seriously believed what they read in the popular in print press, and good Cops and Military died because of it. The book, The Gun, by Shivers, outlines the Colt AR15 psuedo science in the popular press about the lethality of the 5.56. The gun writers of the era were publishing all sorts of Colt stories about arms, legs, heads being blown off by the 5.56, and people took it seriously, and it helped in the adoption of the M16.
I am going to contend that the firearms industry has not needed to conduct lethality research when all they had to do is get some in print writer to sell their bullet in a popular periodical. These guys rummage through their garage and garbage cans, and what is cheap and waste, becomes a tissue stimulant. Two of the most popular test media were wet newspapers and phone books. Free stacks of newspapers have long disappeared since no one reads "old news". I have not seen a phone book in a while. So those "gold standards" are gone. The inprint crowd also shot wood, clay, soap, ducseal, and steel. All of which they claimed calibration against living things by some experience. I have no doubt the media was "adjusted" to give the result the bullet maker wanted. Today, the in print gold standard is water filled milk jugs. When an author gets $400 for an article, it can be understood that he is not going to spend thousands for a ballistic dummy. Rather, these guys have to be driving around on recycle day, robbing the street containers of their plastic waste.
(milk is declining as a beverage, maybe the availability of empty milk jugs will decline. Can someone predict the next in print gold standard for lethality?)
Maybe you know the history better, but it seems to me that the current tissue standard of ballistic gelatin was not established until Dr Fackler, a Government paid researcher, did the publicly funded work to find a decent tissue standard.
And that is why we test on bovine flesh (and bones). It’s extreme, but it’s eye opening.