So that it will still reload the weapon in the background after it runs dry and then you pick up ammo (or pop a synth?) Currently, if there's no ammo in reserve and then a brick is picked up, it sits there just in reserve indefinitely until u pull out the weapon (usually right when you need it...to see a disappointing mag of 0) and then put it away again for the requisite 5 seconds. This perk should be more intelligent than that. Thanks for listening!