I don't know about you, but in my games it's very hard to keep track of all the various items people have. People are so ignorant of the amount of ammo they carry that they might as well have infinite ammo. Carrying capacity is also somewhat ignored because people have no idea how much their stuff weighs.

To help mend this, I'm thinking of making another page for a character sheet. It would have many different outlines of generic weapon clips as well as carrying capacity. For every clip diagram the player would write what weapon that clip is for and how many shots remain. This would make keeping track of many different types of ammo easy. There would also be generic munitions diagrams for items such as grenades that are expended one by one instead of by clip.

How do other people keep track of their ammo and carrying capacity in a more permanent manner?

I used to use, in my WFRP days, an extended character sheet that had tick boxes for ammo. Basically, I had my players blank out all the boxes of the ammo they didn't have (thus leaving the empty ones to mean ammo) and then when the ammo was used, I had them cross it out individually. This meant they knew how much was in a full clip/quiver/quarrel etc, but it also showed them how much was used.

Some of my players, who were a little more on the 'Taking Trophies' line of thinking (which is always fun) used to put a slash for spent ammo, and a cross for ammo that caused significant damage etc, thus showing how good they were against each other. This lead to a fun tradition of my players 'Taking Names' as well of people they killed, and one player started putting notches in his bow stave every time he scored a kill with it.