Negative Airsoft shows a process of an extensive repair and restoration of a heavily abused G&G MP5 airsoft rifle, which was found to be covered in mud and rust with a severely damaged internal gearbox, despite having run for 15 years with "appalling" internal work. He performs a complete overhaul, replacing broken components like the piston and burnt-out switch assembly, and after the service, the gun performs flawlessly during testing. In the troubleshooting session, he determines the owner's secondary feeding issue was not a problem with the newly repaired gun, but rather with the incompatibility and poor quality of his other magazines.