This configuration describes a rifle barrel commonly found on the AR-15 platform. A barrel of this length and gas system offers a balance between maneuverability and velocity. The gas system, positioned at a mid-length point along the barrel, contributes to a smoother recoil impulse compared to carbine-length systems. The presence of a front sight base (FSB) provides a fixed mounting point for iron sights.
The combination of these features results in a platform suitable for a variety of applications, from home defense to competition shooting. The increased sight radius afforded by the longer barrel enhances accuracy, while the mid-length gas system reduces recoil and improves overall controllability. Historically, similar barrel lengths and gas systems have proven effective in military and law enforcement contexts, demonstrating the practicality and reliability of this setup.