The PDI-Japan 230mm 6.01 inner barrel for the Maruzen CA870 series is constructed from durable stainless steel (SUS304). The company says its exceptionally tight 6.01mm inner diameter is engineered to minimize air loss, resulting in excellent momentum transfer for the BB as it's propelled forward. This characteristic makes it optimally suited for short-range engagements, such as those encountered with pistols. However, due to the narrow bore, the airflow overtaking the BB is minimal, potentially affecting long-range stability compared to wider bore barrels.

Given the precise 6.01mm inner diameter, the use of high-quality BBs is advised to prevent performance issues. It is imperative to avoid using substandard ammunition, as imperfections can lead to scratching or jamming within the barrel due to wax or dust accumulation. Regular and thorough maintenance is therefore essential to ensure the longevity and consistent performance of this precision component. Please note that any increase in FPS and range achieved with this barrel is not directly proportional.

The company says, it's important to verify compatibility before purchasing, as this inner barrel is specifically designed for the new MARUZEN CA870 HOP system and is incompatible with older HOP configurations due to significant differences in barrel shape. The barrel features an 8mm outer diameter around the HOP window and 8.55mm elsewhere, which differs from the genuine MARUZEN barrel's uniform 8mm diameter. Consequently, some internal components like the inner barrel spacer may require user modification for proper installation. While the material is a non-magnetic austenitic stainless steel, the manufacturing process may induce some magnetic properties. Additionally, slight variations in laser marking and engraving may occur depending on the production lot, and in rare instances, a faint striped pattern might be visible on the inner surface, though this will not impact performance.