There was a .38 Auto, which preceded the .38 Super.

I think perhaps the smaller round's standard 130gr. FMJ probably had more penetration than the typical .45 Auto and would actually go through more head bone.

For penetration, I think I would prefer a 6" .45 auto loaded with a 300gr. FMJ running 850fps using Blue Dot powder.

Better, would be the .45 Winchester Magnum running about 1,200fps with the 300gr. FMJ. I am not sure what gun it was chambered in - maybe Desert Eagle?

The .38 Super's 1,200fps with a 150gr. would not be in my holster.

My own Colt .45 auto with a standard drop-in 5" Wilson barrel made 960fps with a 260gr. Speer - with their top load of W630 powder. It worked splendidly on a black bear.