Precisely! If the gun had free will, it would be held responsible -- but not the gun manufacturer.
... because the gun manufacturer wasn't aware of the intent of the person who acquired the gun.
Accessory (legal term) - Wikipedia, the free encyclopediaCriminal facilitation
In some jurisdictions, criminal "facilitation" laws do not require that the primary crime be actually committed as a prerequisite for criminal liability. These include state statutes making it a crime to "provide" a person with "means or opportunity" to commit a crime, "believing it probable that he is rendering aid to a person who intends to commit a crime."