On this same topid- two questions? What is the best way to remove a stuck or frozen bushing- and did the post 1913 L.C. Smith guns have different designed firing pins- if so, how were they replaced? The B.P. from this site shows drill rod (high carbon steel) used to machine by lathe turning the three basic sized pins for the pre-1913 series-and then H.T. but no Rockwell range and scale for resultant hardness is shown on the print. I am turning from free machining grade bar stock some "experimental pins" and will possibly harden them with Kasenite- as the rear section of the pin receives the blow from the hammer face-and the tip- today's newer loads may have harder primer faces then those shells of 1900- My guess- Rockwell C-40 range-just a guess, wish the print were more specific.