I am pretty sure Model520 is correct - I don't think anyone means rotation in the literal sense, i.e., Monday is my .38, Tuesday is my 9mm, Wednesday is Glock day, Thursday .... and so forth. Different guns due to dress, weather, etc., is what I presume is meant by rotation, and that rotation implies that that person has more than one gun for carry purposes.

It's like if I was to tell you about my hunting and said I have various rifles "in the rotation" - I would mean that I have several hunting rifles and depending on what I am hunting, or the weather, or something, then I will pick from one of those. Not that the .308 is Monday, the .35 Whelen is Tuesday, etc.

I HOPE that is what we all mean, anyway.