Are there documented cases of "extra" magazine use by armed citizens?

First I'll clarify that I'm not asking about police or security personnel who encounter very different risks than average citizens.My question is this; are there documented cases of an armed citizens using their weapon in a defensive context (legally), completely emptying the magazine, then getting a magazine kept on his/her person for continued legal use?I ask because I often see posts of people carrying with a holster that has a magazine slot, or even using a second "magazine holster" and I wonder if there's any real cases where this has been useful enough to justify the practice. via /r/CCW https://ift.tt/2YbG68A