Black Rain Ordnance BROSS2020FRBB Fission 5.56 NATO 16" 31-Round Carbine

The Black Rain Ordnance BROSS2020FRBB Fission 5.56 NATO 16" 31-round carbine is a modern direct impingement platform purpose-built for patrol, defensive, and training applications where reliability and shootability take priority. Designed for law enforcement, military personnel, and serious civilian operators, this carbine delivers the accuracy and ergonomic handling demanded in close-to-medium range engagements. The 16-inch barrel balances velocity retention with maneuverability, making it ideal for vehicle operations, building clearance, and duty carry across diverse operational environments.

Built on proven 5.56 NATO architecture, the Fission carbine incorporates a direct impingement gas system that cycles reliably across standard, mid-range, and hot ammunition without requiring tuning adjustments. The 16-inch cold-hammer-forged barrel provides superior bore finish and extended barrel life compared to button-rifled alternatives, translating to tighter shot groups and consistent performance over thousands of rounds. At 7.8 pounds unloaded, the carbine maintains a low-recoil impulse and sits naturally during shouldered transitions, critical advantages when cycling through magazine changes or engaging multiple targets under pressure.

Operators accustomed to standard AR-platform controls will find the Fission immediately familiar, reducing transition time for duty teams and training rotations. The 31-round magazine capacity provides extended on-board ammunition without requiring constant reloads during force-on-force drills or qualification courses. Law enforcement armorer compatibility is simplified through industry-standard components; the direct impingement design and modular upper receiver accept most aftermarket optics mounts, rail systems, and accessory platforms on the commercial market. For duty-grade reliability testing and long-term accuracy verification, budget 500–1,000 rounds of mixed ammunition before final load development.