We all heard the term, high powered rifle, or handgun do you know what makes it high powered?

Just like I hear the gun and knew it was an AR15, really ?
Rapid firing might tell you it’s semi automatic but very few can tell what make it is.
Just like when on TV they dig a slug out of a victim and say this was a 308 cal weapon ?
Just just your information a 308, 30–06, and a 300win mag shoot the same slug, the difference is the case.