My biggest fear in Vietnam was running out of ammo in the middle of a firefight. That fear has carried over to my civilian life. I carry a 1911 with 8 round magazines and always, always carry cocked and locked. I also have a two magazine pouch carrier on me.
For those times when I am lounging around the house and the dog needs to be walked, I throw my Glock 36 in a pocket holster and a spare magazine in the other pocket.
I have in excess of 25,000 rounds of ammo in my house at all times. Mostly .45 ACP, 5.56, .40 S&W, and .357 Magnum. I shoot in the neighborhood of 1200 - 1500 rounds per week and try to buy 2000 rounds per week. Some of my purchases are factory new and some are reloads, but rest assured I will never be caught without ammo.
May the Schwartz Be With You.