Shark Hopup Bucking was originally designed to prevent double feeding.
By having 3 special "fins" inside the bucking, Shark Hopup Bucking can more firmly hold one bb on the bucking lips.

As a result in increased 'back pressure' there is a chance to increase FPS velocity, however the velocity adjusted is by a VERY consistent margin. Ex. (300-310FPS -> 320-325FPS). Though there is a increase in FPS, the variance in FPS drops significantly on some builds.

Its a great solution to prevent "rollers" on some AEGs, and especially made for guns with trimmed tappet springs, as it helps prevent the BB from being over-shot into the barrel by the tappet/air nozzle before the piston is released.

Package Includes: Two buckings, two Fishbone spacers