I often get confused when referring to gun sizes. I often say "caliper" when the term used is "caliber". Looking at the defintions, it seems to make no sense as "caliber" has two very different meanings; "caliper" also has two very distinct meanings.
the quality of someone's character or the level of someone's ability.
a) the internal diameter or bore of a gun barrel. b) the diameter of a bullet, shell, or rocket. c) the diameter of a circular body, such as a tube, blood vessel, or fiber.
an instrument for measuring external or internal dimensions
having two hinged legs resembling a pair of compasses and in-turned or out-turned points.
I think the confusion comes in the because when talking about "the internal diameter or bore of a gun barrel" one would think a term referring to a "instrument for measuring internal dimensions" would be more closely related than a word whose main meaning is "quality of character".
Is there a reason why "caliber" was chosen over "caliper"?
They are only one letter apart, so did they have a similar origin that eventually became more divided?