When the ammo shows as 0000, it means there is an error in the CSWeapon.xml. When I mess around with the CSWeapon.xml and see the ammo at 0000 when I load the aircraft, I know I made a syntax error when I modified it.

If this is happening by just adding it to the aircraft (without modifying it) it probably means that the FSX\Captain_Sim\weapon\loader\cfg\unit.dat is corrupt. Use the Extended Download Service and download a new installer.

Mark