I too, broke my model 13-2 firing pin by dry firing. I sent it off to Frank Glen and decided to get a basic trigger job while he replaced my firing pin. Frank told me it appeared to him that my firing pin seemed to break due to it hitting the top portion of the firing pin hole. He added that the early pins where not spring loaded and were susceptible to raising ever since slightly through inertia. He installed a model 66 spring loaded firing pin to prevent this from ever happening again.

I was shocked when I saw the broken pin since I’ve always dry fired my center fired Smiths for decades but evidently, it can happen!