The thing about "testing" (and I use that term loosely) on YouTube from people like Paul Harrel is that you can't really extrapolate any meaningful data on that. Even the "meat targets" are all different from one another, you can get different results each time. Same with cinder blocks. The variation between density/etc. from block to block is pretty substantial. And sure, yeah, generally .40 is going to do more against a hard target like a cinder block or steel plate, but that tells us literally nothing about how effective a round is on a human attacker. A boxer can run up and punch a steel plate with more ft/lbs of energy than a .40 and knock it down with gusto, that doesn't mean it's going to be more effective at stopping an attacker than a bullet. Humans are basically big water sacks that absorb shock incredibly well. Tissue stretches, its elastic and bounces back to it's original shape when dealing with 9mm, .40, and .45. The only tissue that is permanently damaged is the tissue directly destroyed by the crush wound of the bullet passing through. That's why hollow points with sharp edges show such impressive performance, they rip and tear like a knife... because that's all any service caliber handgun is, essentially, a knife that bores through tissue. What matters is what tissue is destroyed. FBI-spec Ballistic Gel blocks aren't perfect by any means, but unlike amateur testing done on youtube, it actually does give meaningful data which conclusions can be drawn from. Each test block (if properly formulated according to spec) will give a very good comparison on how rounds perform against one another in a homogenous substance, and various published scientific papers have proven a strong correlation between how a bullet acts in gel and how it acts in the human body. LE agency after LE agency has confirmed this by comparing autopsies from actual OIS incidents with properly-conducted ballistic testing.