Overcharge: Add a 1.5x headshot multiplier (currently 1x), as of now the damage is lacking enough that not even the gimmick damage boost can make up for it.
Captain's Handgun: Change to 2x ammo usage (currently 4x), while the utility of not having to reload the gun at all is very useful, the damage it produces doesn't seem to warrant 4x ammo usage, even with the no-reload mechanic.
All the other guns seem perfectly fine where they are, but these are just some things that stand out a bit to me with those 2 guns.