Jerry you will notice when McLaren does the watermelon tests the FMJ goes though the melon and the exit hole is a little larger than the entry hole plus there is some fracturing on exit. The frangible round enters the melon leaving a small entry hole, travels some distance and explodes taking the whole front end of the melon apart. We see this time and again as in Alvarez’s experiment.
Anything to do with a melon is a soft-tissue test. Now Dr. Alvarez termed his wrapped melon (two layers of one-inch Scotch filament tape) a "reasonable facsimile of a human head" but Tony Szamboti, a mechanical engineer, critiqued Alvarez's study and claimed:
"the force required for the same object to penetrate and shear through the same
thickness of live human bone vs. that required for a melon rind, is at least 100
times greater, and 50 times greater even for dead human bone."
Hard to imagine a .223 round impacting something 100 times harder than a melon rind and still perform as if it were in a gelatin block or melon.
With regards to the McLaren melon tests, the 6.5mm in soft-tissue has a uniform and steady temporarily cavity and wouldn't begin to tumble, if at all, until well pass the length of the melon. A tumbling or disintegrated FMJ round (as from impacting skull bone) would have a different temporary cavity.
6.5mm "Carcano" gelatin test for Cold Case JFK
The .223 round tumbles almost immediately and maybe separates early, producing a greater temporary cavity in a shorter space. The Australian .223 study makes me wonder if the .223 round would have sufficient force to "explode" a wrapped melon. In any event, we're still taking about soft-tissue events which has limited relevance to a skull wound.
So the .223 round has a "tumbling" advantage over FMJs in soft-tissue. But in regards to a skull wound, the FMJ would likely tumble and disintegrate as well, depending on how it struck the skull bone.
In defense of Dr Alvarez:
To explain a little about Dr Alvarez, I don’t know this to be a fact but coming from an engineering background I see it as this. Regarding the multiple different results of shooting various “fruits” and seeing the results and increasing the velocity of the bullets and finally getting the same results as we see happened to JFK. He kept trying and trying until something worked. It wasn’t that he was hiding the results of the failed attempts; in R&D we do a lot of that kind of thing, keep at it until you get it right. And as far as Vela Incident, the US and Israeli governments can cover up anything and in the process shred someone’s reputation. I know there are no facts to back this up, it’s just the way I see it from what I know and have experienced.
The Alvarez tests had explosive results using soft-nosed 30.06 bullets striking melons but apparently only if the melons were wrapped (two layers of strong one-inch Scotch filament tape). Alvarez doesn't much say what happened to the melons that weren't wrapped. Dr. Lattimer, in 1975, repeated the Alvarez wrapped-melon test using 6.5mm FMJs, claiming to have produced similar recoil results.
So we're back to melons tests by Alvarez/Lattimer and McLaren being soft-tissue, possibly having some application in showing the effects of a temporary cavity in a soft tissue mass, like the brain. But to get to that soft-tissue in a living human first requires impact and penetration on skull bone, which in turn induces the factor of bullet tumbling and, mostly likely, disintegration at the entry site.
What I am trying to demonstrate as was Dr Alvarez is that a frangible round traveling at 3,000 ft/sec entering the back of JFK’s head gets ¾ of the way through his head and explodes. I don’t think Alvarez was hiding anything, I think he was just trying to demonstrate the effect. I have seen many other videos of others do the same experiment with the same results.
Unfortunate the Alvarez and McLaren results fall into the soft-tissue test category.