I would like to apologize that nobody has replied to you on this. It's a great idea, tough to implement as it would require a differentiation between weapons with and without mags, and it would also require a magazine model and in-game item for each weapon that needed one. The in game item itself would have to keep track of it's current ammo as well, and scale its own value based on that. One thing I'd change is the need to visit a reloading bench to put bullets in a magazine. I think that you should be able to do it anywhere, but you have to watch an animation for it, which would also require effort. Basically, this needs a good mod TEAM.