This high-quality CNC-machined upper receiver kit converts a GHK M4 V2 or V3 GBBR system into a dedicated bolt-action platform. By replacing the entire upper receiver including the charging handle, it enables bolt-action-only operation – perfect for sniper builds or fields with semi-auto restrictions.
Made entirely from CNC aluminum, it offers a rigid and wobble-free setup for precise shooting without gas loss from a blowback mechanism.