[ithacaartist]

Welcome to the forum, Anton.

You are asking about a hole in the top firing pin? It is unclear to me what you are calling the "hole". If you are asking about the grooves ground into the front shoulder of the firing pin, just behind the tip, then this would be called a "relieved" or "fluted" firing pin. These grooves were added--1914 or thereabouts, not exactly sure--and would allow the ignition gas pressure from a pierced primer to mostly pass by the firing pin instead of forcing the pin violently backward within the breech block--likely causing damage. Some also say that the grooves allow for somewhat of an accumulation of fouling before the firing pin is affected by it.

Also, a qualified technician would be able to weld material onto the one with the broken tip, and re-shape/restore the tip. This might be important to do if the firing pin is matching-numbered.

David Parker