Stupid Airsoft gets an upgrade kit by Tapp Airsoft designed for the GHK G5 gas blowback airsoft rifle. This custom lower receiver allows the replica to run on high-pressure air (HPA) while utilizing ASG Scorpion Evo magazines. By combining these systems, the modification aims to merge the consistent performance and cost-efficiency of HPA with the realism and tactile feedback of a traditional gas blowback platform.

A large portion of the video serves as a step-by-step tutorial for the installation process, which involves stripping all the internal firing components from the original receiver and rebuilding them into the new 3D-printed housing. The process requires a fair amount of patience and steady hands, especially when wrestling with the tiny internal springs and pins. Stupid Airsoft notices that while no permanent modifications are required, the complexity of the rebuild places this project firmly in the advanced or expert tier for airsoft teching.

During backyard testing, the modified rifle successfully feeds ammunition on both semi-automatic and full-automatic firing modes without any hiccups. The setup retains the realistic manual of arms, including a functioning bolt release and the ability to stop firing when empty, which is a rare feat for standard HPA adapters. Despite the minor inconvenience of being tethered to an external air tank, the system eliminates cold-weather performance drops and the classic aroma of propane gas.