Tempering bullets to pierce bullet—proof armor
Heat the lead bullet as much as you can without melting it, and once it is hot dip it into the strongest vinegar that you can. And do this four or five times. Afterwards, mince some lard very finely and some linen also very delicately, mix all this together and use it as wadding, making it go into the arquebus or pistol with a little strength and very tightly. And before shooting, if possible, the bullet should be hot.