Steyr 1908

[azlaw]

These guys tested the firing pins from the Llama, a Colt 1911, and an AR15 firing pin that was rattling around in my car. They go on and on about RC hardness curves and ASTM specs and blah, blah, blah. I am impressed that the subject of metallurgy and heat treatment is very deep, and that kitchen table gunsmiths like me should stay on the porch...

Bottom line on a firing pin seems to be that real gun manufacturers do heat treat firing pins, and this is essential for a proper service life. That said, they used some kind of steel that was pretty hard, and said that it will work fine but will eventually deform with much use.

H

[sheepherder]

Originally Posted by azlaw

...and that kitchen table gunsmiths like me should stay on the porch...

I would happily join you...

I am a shade-tree gun hack, and I have learned many of my limitations...Using anything higher than 4140 steel is too expensive for my work...Steel like 8620 work hardens quickly, especially in thin areas...8620 will get harder than HSS drills, reamers, and end mills...I have the invoices and box of junk tooling to prove it...

4140 (also called 'Ordnance Steel') is what I use now for firearms parts; it is quite user-friendly but can still be hardened & annealed/tempered...

Production firearms are like any other commodity; they are made to the lowest possible specifications to keep cost down...

If whatever was done by the OP's smith caused it to break, then IMHO, that smith did something wrong...

...$.02...