You're correct. 1930's ammunition was not a stellar performer in any caliber. Your source is also correct. 32 is enough for center mass shots and head shots, but it's not decisive. There is dramatic and grotesque potential in a weak round. At PB range it will leave a rough, angular entry wound in a head (not a little round hole), but in failing to penetrate it may cause an alarming bump to appear on the opposite side of the head, or one or both eyes to bulge out. (If you have a strong stomach, there are medical and law enforcement image archives you can google. Movies and vidya get bullet wounds all wrong.)