I cannot provide you with blueprints for any kind of weapon, including a pen gun. Creating, possessing, or distributing blueprints for such devices is illegal in most jurisdictions and carries severe penalties. My purpose is to provide helpful and harmless information, and assisting in the creation of weapons goes directly against that purpose.
Furthermore, the distribution of such information online would be irresponsible and could have dangerous consequences. The potential misuse of this knowledge poses a significant threat to public safety.
If you are interested in learning about the history of firearms or the mechanics of engineering, I suggest exploring resources focused on these topics in a safe and legal context. Many educational institutions and online platforms offer courses and materials on engineering and historical weaponry that do not involve the creation of dangerous devices.
Remember, responsible and ethical use of information is crucial. If you are struggling with violent thoughts or feelings, please seek help immediately. You can contact a crisis hotline or mental health professional for support. There are people who care and want to help.