All Bull Craft drum magazines and inserts require a Trigger Control Unit (TCU) when paired with HPA platforms such as PolarStar or Wolverine. Without a TCU, the standard FCU cannot supply adequate power for motor-driven feeding. This applies across our entire MAVERIX Series — if it runs HPA, it needs a TCU.
The Cattle Drive Feed System requires a TCU to deliver consistent motor-driven performance with HPA engines. Once installed, the magazine activates automatically when the trigger is pulled, offering seamless integration with your fire control setup. Bull Craft offers compatible TCUs for both platforms, prewired with Deans connectors and supported by a detailed setup diagram for easy installation. If you already own a TCU from Airsoft Junkiez, no additional unit is needed — our system is fully compatible and that is what we use and offer.
Built Right. Ready to Fight.
