Earlier quoted context omitted.
My understanding of it (and wikipedia seems to back me up) is that the term 'clip' when used properly refers to the device used to assist in loading a magazine. For example, you use a clip to load ammunition into the (internal) magazine of an M1, and you could use a clip to load ammunition into a "banana clip", which actually refers to a style of magazine.
You're referring to "stripper clips" that were invented before guns had removable springed magazines. Those are a type of clip (and lead to the term), however the slang term clip doesn't refer to pistol magazines - it's merely slang for a magazine. It's a common misconception and what I was responding to. In fact, the internal pistol magazine of a C96 pistol is still a magazine, but it loaded by a stripper clip, and…
https://secure.wikimedia.org/wikipedia/en/wiki/Clip_%28ammun...
Using the term "clip" to mean "magazine" is both slang, and incorrect.