BnF Ms. Fr. 640 offers a wealth of information on gunpowder weapons. During the wars of religion, gun technology was of the utmost importance, not only for those who produced these instruments of war, but also for those who made a profession of arms and had to ensure that these guns were safe to use. This essay examines the entries in Ms. Fr. 640 relating to weapons against the backdrop of this turbulent period in and around Toulouse, and compares them to other sources that treat gunpowder weaponry in sixteenth-century Europe.