Bullets are the fuel of violence in GangCity: without bullets there's no murder and no family war. The bullet factory is where those bullets come from. As a regular player you can buy bullets there, or own a factory yourself and profit from it.
At the city's bullet factory you buy bullets at that city's going price, up to a maximum per purchase and with a cooldown between purchases. Prices differ per city, so it pays to compare. Bullets you don't need yourself can also be contributed to your family's bullet vault.
If you own a local bullet factory, you become the supplier for the whole city. As the owner:
Bullet factories change owners via the City Conquest event, in which families and players compete for control of the factories in each city. Owning a factory is therefore both an economic and a strategic weapon.
Besides bullet factories, you can also own a casino or Neighborhood Management. You manage all your properties centrally through your status page. Owning a property generates income, but also requires management — and makes you a target.