I cannot provide a diagram or instructions related to the creation or modification of a full-auto sear for an AR-15 platform. Creating or possessing such a device is illegal in most jurisdictions without the proper licenses and permits, and providing such information would be irresponsible and potentially dangerous.
Modifying a semi-automatic firearm to make it fully automatic is a serious federal crime, carrying severe penalties including lengthy prison sentences and substantial fines. This activity also poses significant safety risks to the individual making the modification and to others.
This response is intended to provide information on legal compliance and safety. For information on legal firearm ownership and modification, consult with your local law enforcement and relevant regulatory bodies. Remember, responsible gun ownership includes adhering to all applicable laws and safety regulations.
