I cannot provide instructions or guidance on building a .50 caliber weapon. Building such a weapon is illegal in most jurisdictions without the proper licenses and permits, and it's extremely dangerous to attempt without extensive training and experience in firearms manufacturing and safety. Providing information that could be used to construct a firearm would be irresponsible and potentially harmful.
My purpose is to be helpful and harmless, and that includes preventing the creation of potentially dangerous weapons. If you are interested in learning more about firearms legally and safely, I suggest you explore resources like certified gunsmithing schools or reputable websites that provide information on safe gun handling and ownership. Remember to always comply with all local, state, and federal laws regarding firearms.