[SPARK] Hisei Kai High-Precision Inner Barrel, 6.05mm Bore, 229mm for Next-Generation MP5

The ultimate inner barrel that delivers performance that satisfies SPARK custom engineers.

"Hirei®" is a high-quality, ultra-precise inner barrel made entirely in Japan, developed with the cutting-edge metalworking techniques of the craftsmen at "da Vinci," the manufacturer of the custom barrel "Guren/Raizen" series, and the SPARK concept. Further refinements have been made in various areas to create the ultimate inner barrel, "Hirei® Kai."

The base material is made from the highest quality domestically produced stainless steel produced by cold forging, and the product is carefully crafted by Japanese craftsmen using domestically produced high-precision CNC machines.

To ensure a stable hop-up effect, the hop-up window has been carefully shaped and polished, and the end of the barrel has an ultra-long taper of 20 mm, designed to create a layer of air that envelops the BB bullets!
The synergistic effect with the 6.05 mm tight diameter improves initial velocity, accuracy, and distance.

"Hiei" is a registered trademark of SPARK, an inner barrel for airsoft guns.

* Also compatible with the first batch of the next generation electric gun MP5A5.

[ Features of Hirei® Kai ]

• Super polished HOP window

A stable hop-up is important for a stable trajectory.

The interior walls, including the area around the HOP window, are thoroughly polished by craftsmen to eliminate any uncertainties that may affect the BB bullets.

The HOP window is subjected to a "round cutting process" which is extremely difficult to process, which allows the HOP packing to move smoothly and maximizes its performance.

• 20 mm ultra-long taper

Due to its extremely hard nature, cold-forged stainless steel is extremely difficult to machine, requiring highly precise CNC machines, skilled craftsmen to select cutting teeth, and meticulous machining programming. The exceptionally long taper of 20 mm suppresses sudden changes in resistance around the barrel exit and increases in turbulence coefficient, eliminating the negative effects on accuracy. This maximizes the gun's inherent accuracy.

• Proudly made in Japan

It is easy to describe the precise round cutting of the HOP window, the polishing of the inner surface of the barrel, and the long taper processing of the muzzle side, but creating an ultra-precise inner barrel using cold-forged stainless steel, which is difficult to process, requires a high level of technical skill.

"Hirei® Kai" is a MADE IN JAPAN product that Japan is proud of around the world.

[Notes]

• This product is intended for ages 18 and over, and cannot be purchased by anyone under the age of 18.

• Even if the product is new, there may be scratches on the product itself or its accessories from the time of shipping. Even if the product is the same, there may be differences in color between individual products, but these are all within the product specifications.

• The external specifications and accessory configuration may change without notice. In addition, the original box may be modified or repackaged if the packaging is missing or damaged.
• When installing, please be careful not to violate the legal power by using a muzzle velocity meter or similar device.
• Processing and adjustment may be required for installation.
• The product description does not guarantee improved performance.