Okay, let me first admit that I've skipped forward to the end of the thread. Sorry I got here late, and more sorry if I repeat anything that has already been said. For me, adequate supply fo ammunition means enough that I bring some home when the problem is solved. If I have my way, and I will, I'll be adding mags soon enough, with the AWB dead, and hi-cap mags priced somewhere below gold and platinum.
My carry gun is a Glock 19. I wear it in a Jackass rig with two Glock 17 mags, with the +2 adaptors. 54 rounds should get me through the night, as I use this set-up for when I'm on-call, goinmg to crime scenes, helpiing with search warrants, etc.
During the day, when it's a suit and tie, I carry the same Glock with one mag as a reload. 35 rounds should do fine.
I just never want to find myself in a situation where I;m holding an empty gun, praying for help to arrive.