I'm playing a soldier and I've got both Incendiary Ammo and Disruptor Ammo at level 4. I see that at level 5 for each, there's an option for +30% ammo.

I'm trying to plan out my build but don't currently have the skill points to test this out for myself.
Is this a passive ammo capacity bonus that is in effect even if I'm not using that particular ammo power?
If so, will the ammo capacity bonus from different ammo (such as Incendiary and Disruptor) powers stack, such that I'd have +60% capacity?