[Kuramae Kobo] APS-1 Grand Master BRASS Plated Cylinder + New Genuine Piston Cup Set

This is a custom cylinder exclusively for the APS-1 Grand Master series.
*JASG certified part.
*This product is intended for those who can disassemble and assemble the APS-1 themselves.

This is a custom cylinder made of brass, with a brass-machined cylinder head/cylinder end, and then chrome-plated.
*The [APS-1 Grand Master BRASS Plated Cylinder] is a JASG certified part.
*When installed in the APS-1 Mk.3, the muzzle velocity will be around 87 m/s.



Compared to the genuine unplated aluminum cylinder, both strength and durability are greatly improved.
The chrome plating reduces friction, preventing wear of the piston cup and significantly reducing dust generation, thereby allowing for less frequent maintenance.

Additionally, initial production lots of the APS-1 Mk.3 have shown symptoms of reduced muzzle velocity caused by the genuine cylinder, and replacing it with this cylinder can fundamentally solve the problem.
*If using with an APS-1 Mk.3 first lot, the piston cup must also be replaced with a new one at the same time.



It also reduces friction between the cylinder and the frame, allowing for extremely smooth cocking.
*The gun body is not included in the product.


・Features a nozzle-integrated, disassemblable cylinder head, reducing the possibility of air leaks.
It also contributes to increasing the rigidity of the nozzle.



・The cylinder end can be disassembled with two Phillips screws.
*When removing the piston, please remove it from the rear as much as possible.

・Set contents
Cylinder (chrome-plated brass)
Cylinder head (with O-ring/chrome-plated machined brass)
Cylinder end (with 2 fixing screws/chrome-plated machined brass)

*The piston/spring/spring guide use genuine parts.


Regarding installation in APS-1 Mk.3
In the first lot of the APS-1 Mk.3, abnormal wear of the piston cup caused by the genuine cylinder has been confirmed, and the piston cup must also be replaced with a new one.
If installing this product in an APS-1 Mk.3 first lot, please order the piston cup set.


Precautions during maintenance
When disassembling the cylinder for maintenance and removing the piston, please remove it from the cylinder end side as much as possible.


When inserting the piston, insert it from the front.



～How to distinguish between the first lot and second lot of APS-1 Mk.3～

・APS-1 Mk.3 purchased before September 6, 2024, are first lot.
・Units with serial numbers starting with MB166～ are first lot.
・If you remove the magazine rail, there will be a brass insert on the main body side, and
　units with only one insert are first lot.