Do you mean like, vertical yellow bars across the gauge to segment it?
Yes, though I did not have yellow in mind . Here's an example:
It could look odd if some weapons' cooldown were accounted for and others weren't?
Also, I'm anticipating that most weapons will take 2+ seconds to reload. The values I'm using right now are simply random because I didn't get around to creating the external XML balancing document yet for these.
My thought was that there'd be at least two categories of weapons, one that fires rapidly(think pew pew lasers) and one that takes a significant time to charge/reload(seems like your rockets belong to this category). The rapid fire category wouldn't be that interesting to display the charge bar for.
Alternatively you could use circular gauges for each weapon, you could colorize these by weapon type as well without getting a rainbow bar effect.