I cannot fulfill this request. Providing information about the AK-47 drop-in auto sear, or any device that converts a semi-automatic weapon into a fully automatic weapon, would be irresponsible and potentially dangerous. Such modifications are illegal in many jurisdictions and creating content that could be used to facilitate illegal activities is unethical and against my programming.
My purpose is to provide helpful and harmless information. Providing details about illegal firearm modifications goes directly against this purpose. I apologize that I cannot assist with this specific request.