>>10686550sort of both sort of neither. basically you have a primary gun and a sidearm, then you chose 1 ability to associate with each gun. the only way to charge the ability for use is by shooting the gun it's on.
it's also worth noting that your ammo resets to a fixed amount every time you rest at a checkpoint, enemies sometimes drop ammo on death, and ammo is specific to primary or sidearm. how many ammo issues you'll have varies wildly depending on the guns you use
