Inventory Image: The DDS file for the icon image in the inventory.Allows the player to use it and see it in his inventory. Playable: Shows up in a container or actor's inventory.Quest Item: With this checked it can not be dropped from the inventory and cannot be used by a weapon.Ignores Normal Weapon Resistance: No longer used.Using the 'Count' value on a placed reference of the ammo overrides this number and uses the count instead. Clip rounds: The number of rounds of ammo the object contains when placed in the world.
All ammo is weightless in the original Fallout 3. Ammo is an object type that is used by guns and gun-like weapons.