As a replacement for traditional three-piece gas rings, the JPEGR-223 utilizes a one-piece design similar to the Mcfarland rings. Unlike the Mcfarland rings, though, our precision-ground gas rings are engineered to precisely fit Mil-Spec components as well as our own JP EnhancedBolt. After testing numerous minute grind callouts, the final JP Enhanced Gas Rings spec is the perfect balance of a solid gas seal with a very low-friction relationship between rings and bolt carrier. Reducing the resistance between these components directly results in an overall increase in the rifle's operational window while the edge of the rings utilizes the cycling action itself to scrape the walls of the carrier, helping shed fouling with every shot.