A few games ago I was playing as Support to get the Support XP daily, and when I switched to Sharpshooter in the shop menu I suddenly had two 9mms with their own slots and ammo pool, essentially giving me 530 pistol ammo(I tested this by firing one and only it's ammo pool when down). I even switched to Medic in the last round and still had this glitch. This was on the Krampus map.
I'd show you a screenshot via attachment, but the board won't allow me to.