NBU Ribbed Cylinder – Full (400 plus mm)

AirsoftParts NBU Full Cylinder for Bore Up Air Seal Systems
The larger cross-section combined with the full non-ported design provides a higher usable air volume, which is why the manufacturer recommends this version primarily for builds with long inner barrels of 400 mm and more, such as various AUG or AK configurations. Due to the enlarged diameter, the cylinder must be combined with a corresponding NBU piston head and NBU cylinder head; standard versions of these two components are not designed for this cylinder. The cylinder is made of stainless steel, and its polished surface provides a smooth, low-friction working surface for the piston head seals. The manufacturer also specifies concentric machining. The cylinder weighs 25.3 g, has no external cooling grooves, is designed for V2 and V3 gearboxes with the corresponding NBU air seal system, and the maximum recommended spring is M170.
Key Features

NBU / Bore Up Design
The enlarged 24.7 mm inner diameter provides a larger cross-section and higher air volume than a standard cylinder, which is the main characteristic of an NBU / Bore Up air seal system.

Full Volume for Long Barrels
The non-ported design uses the full working volume of the cylinder, and the manufacturer recommends it primarily for AEGs with inner barrels 400 mm long or longer.

Polished Stainless Steel Surface
The cylinder is made of stainless steel with a polished surface, providing a smooth working surface and reducing friction of the sealing elements as the piston head moves.

Designed for a Complete NBU Air Seal System
Due to the 24.7 mm inner diameter, the cylinder must be used with an NBU piston head and NBU cylinder head. Standard versions of these components..