Frontal area of the mushroom is at least as important, and perhaps more so....
The laws of physics don't alter, so theres no "perhaps"...FA either has the same, less, or more- effect on penetration(than weight retention) iF a persons bullet testings was thorough enough and they also had the correct & accompanying mathematical modelling to compliment and reinforce their physical findings (in the appropriate test media) it would make your view much more convincing.
Every long established and trusted finding in physics has proven but rather complex math formulas that support the physical findings/results. but I rarely if ever, see people presenting such important supporting mathematical information when presenting their theories on how & why various hunting bullets perform.
An example was a guy on AR who bizarrely claimed one brand of bullets were "non-Con"... that they supposedly were non -conventional/revolutionary in the way they react in target, but he blatantly ignored the fundamental but vitally important fact in physics( or simply didn't know) ..that all hunting bullets work on precisely the same "model in physics"..regardless of design, construction or materials....but he constantly tried to impress and convince people who were non the wiser, of his highly flawed-erroneous claims & theories.
-Bulletproof and Waterproof don't mean Idiotproof.
