Area of a circle the diameter of common calibers

The nominal 9mm/357 as a standard, the .44-.45 is basically a 50% larger "hole". While the .40 is (0.1256"sq. +/-) only 25% larger. I never saw it as such.

The hydraulic displacement effects on tissue are largely lost on sidearms, compared to rifles. So that "hole" is more important as a factor. To my thinking. I've seen that on hogs for sure. But that area, adding to weight and speed of a projectile, will certainly influence penetration. The "shape" seems to be a major factor on it remaining true to it's intended path.

A comparative on a 200 gr. .40 caliber cast bullet fired at 1000 fps vs a .45 cal. of the same, would be an interesting field study. One started some 150 yrs. ago, the .45 Colt vs the .38 WCF is very interesting. Both valid enough that a following remains for both calibers. Until late, a comparative out of lever guns could not be easily seen. The .38 WCF was wildly popular in carbines. I think the thin rim of the .45 Colt and the Winchester/Colt "understanding" cut us short for early big bore pistol caliber carbines. But where was Marlin?