How to use f14b weapon system

[hw0wei]

How to use f14b weapon system
Gun: At startup, the ammunition store is filled with 675 round. It's not possible to refill without quiting FG. To fire the M61A1 Vulcan:
Select HUD A/A Mode on the Display panel, on pilot's right console. A multikey shortcut is also available (:AHa). Having the HUD in this mode is not mandatory though there won't be any symbolics available for the gun in other HD modes.
Select Gun mode with the Stick Weapon Mode Selector (w). A pipper, the G symbol with a number showing approximately the remaining rounds x 100 and a closure rate scale are displayed in the HUD. The closure rate scale is active only if a target is locked by the radar with TWS AUTO mode (diamond on the HUD).
Switch Master Arm on, the X on the G symbol means Master Arm off or in training mode.
Press e to fire the gun.
I follow the instructions they cannot achieve a detailed description of how to use

[Cael]

Are you using the f14b version than comes with FG? It isn't the most up-to-date version actually, Alexis, or xiii, updated it... as u can see here