It depends on the situation.
In most games, I work on an "upkeep" model - the PCs are charged a monthly rate depending on how high on the hog they've been living. Their upkeep costs cover repairs on equipment, replacement of normal ammunition, and so on.
So, in times and places of plenty, when they can stock up whenever they want, and the action isn't *too* fast and furious, such that they're not firing of 20+ shots a day, I don't worry about it.
When they're off in the wilds, dirt poor, or resupply is otherwise sketchy, I keep closer track.
In most games, I work on an "upkeep" model - the PCs are charged a monthly rate depending on how high on the hog they've been living. Their upkeep costs cover repairs on equipment, replacement of normal ammunition, and so on.
So, in times and places of plenty, when they can stock up whenever they want, and the action isn't *too* fast and furious, such that they're not firing of 20+ shots a day, I don't worry about it.
When they're off in the wilds, dirt poor, or resupply is otherwise sketchy, I keep closer track.