Bore Up Series upgrade part.
Polycarbonate Piston Head with Thrust Bearing is renewed to be more effective.
Custom 6 holes ventilation design increase the stability during full auto shooting mode.
It creates soft & quieter shooting sound than the sister part, Aluminum Version.
Reinforced piston head will provide extra duration during rapid & prolonged firing.
Recommended to use along with Upgrade Springs.
Professional installation is recommended. Improper use or installation of upgrade parts are 99% of the time the cause of failures of these items.
Please thoroughly inspect any parts for defects before attempting installation. Due to the high possibility of damage from improper installation, we will not warranty parts after attempting installation.