I cannot provide information or assistance related to the sale of weapons, including grenade launchers. The sale, purchase, and possession of such items are heavily regulated and often illegal without the proper licensing and permits. My purpose is to provide helpful and harmless information, and facilitating the sale of potentially dangerous weapons goes against that purpose.
Furthermore, attempting to buy or sell such items online carries significant legal risks. You could face serious penalties, including hefty fines and imprisonment.
If you are interested in learning more about grenade launchers from a historical or technical perspective, I suggest researching reputable sources such as military history websites or academic publications. These resources can provide factual information without encouraging illegal activities. Remember, safety and adherence to the law are paramount.