The ultimate inner barrel, achieving performance that satisfies SPARK custom engineers.
The "Hiei®", a purely domestic, high-quality, ultra-precise inner barrel, was developed using the cutting-edge metal processing technology of artisans at "da Vinci," the manufacturer behind the custom barrel "Guren / Raizen" series, and SPARK's concept. From there, further improvements were made to various parts, resulting in the birth of the "Hiei® Kai," the ultimate refined inner barrel.
It is made from the highest quality domestically produced SUS304 stainless steel, manufactured through cold forging, and precisely machined using a domestic high-precision CNC machine.
To achieve stable hop engagement, meticulous attention has been paid to the shape and polishing of the hop window, significantly reducing wear below the hop window and the adhesion of dirt to the inner wall that occurs when applying hop.
The barrel's end features an unprecedented 20mm long taper, which reduces exit loss in fluid dynamics, improving accuracy and range.
*The airsoft gun inner barrel "Hiei" is a registered trademark of SPARK Co., Ltd.
■For Next-Gen MP5/EVOLT
Complies with the standards of Tokyo Marui Next-Gen Electric Gun MP5 series and Tokyo Marui EVOLT series.
As there are no clear standards defined, please understand that some overseas products, even if they claim the same standard, may not be compatible.
【Features of Hiei® Kai】
Super Polished Hop Window
- For stable trajectories, stable "hop-up engagement" is crucial.
- Artisans meticulously polish the inner wall, including the area around the hop window, to eliminate unpredictable factors affecting BBs.
- The hop window is processed with "round cutting," which is extremely difficult, ensuring smooth movement of the hop packing and maximizing its performance.
20 mm Ultra-Long Taper
- Extremely hard cold-forged stainless steel is very difficult to process due to its hardness, requiring a high-precision CNC machine, selection of cutting tools by skilled artisans, and precise machining programs. The unprecedented 20mm ultra-long taper suppresses rapid changes in resistance and increases in turbulence coefficient around the barrel exit, eliminating negative impacts on accuracy.
- This brings out the gun's inherent accuracy to its utmost limit.
Pride in Japanese Manufacturing
- The intricate round cutting of the hop window, the polishing of the barrel's inner surface, and the long taper processing at the muzzle end are easy to describe in words, but creating an ultra-precise inner barrel from difficult-to-process cold-forged stainless steel requires high technical skill.
- "Hiei® Kai" is a MADE IN JAPAN product that Japan is proud to present to the world.
