Continuation of the cleaning skills video from RA-Tech with this new episode showing you how to clean the lower receiver of the Gas Blowback M4. You will need Silicone Oil and tissue paper just like the way you cleaned the upper receiver. Now, the M4 here looks like the M4 prototype shown in a previous video with no really relevant information at all. This video shows it to be a RA-Tech M4 Gas Blowback with MOE prototype.