38 special: Why is it only .357 caliber?

This is a supplemental video to the one posted on the Smith and Wesson Model 10 (https://youtu.be/PJosg4SjcJI). This is a more in depth explanation of why the 38 Special cartridge is only .357 caliber, and not an actual 38. All statement made are based upon my own conclusions from reading I have done on this subject to satisfy my own curiosity. Any misunderstandings or misrepresentations that might have been made are not intentional. I do not pretend to be a firearms historian nor an expert on the subject.