All ranged weapons in Entropia Universe use ammuntion. There are 6 types of Ammo in PE.
The Trade Terminal sells ammo in packs of 100, 1000 and 10000 (1, 10 and 100 ped, respectivly). Ammo can now also be looted from creatures when they’re dead, although the ammo size and type is random. If you have some extra ammo left, you can sell it back at the TT and get the actual full value back.
Handguns Like the Omegaton M2100 Use Light Weapon Cells And Carbines or Rifles Like the Sollomate Opallo Use Medium Weapon Cells.
Different weapons use different types of ammo. Make sure you know what kind your weapon uses. Laser weapons cannot use blp ammo, and vice versa. Each weapon has a certain ammo burn. This quantity is how much ammo is used for one shot with that gun. For example the Sollomate Opalo has an ammo burn of 2. That means when you fire one shot, the gun will use up 2 ammo. So if you only have 1 ammo then you cannot fire the Opalo. More advanced and stronger weapons have higher ammo burn, which means they will take more ammo for the same number of shots with a lesser gun.