I know that Savage swapped from the larger diameter pin to the smaller pin at the same time they started chambering for some new mags. I had a staggerfeed w the large pin and then wound up w some Stevens w the newer small pins. The difference is pretty significant and apparent. Initially you'd supposed it was done to increase crosspin strength to allow for camming higher pressure cartridges. But, that change really didn't have any affect on the load carrying ability of the crosspin. The shear areas of the crosspin are out on the ends, nowhere near the thru hole. So, I figure they might have done it just for less frictional area on the firing pin and for a lighter firing pin---better lock time. Indeed there would be added strength to the crosspin, but not in a place that matters. Does anybody have any thoughts on this or know any other info on it?
When crosspins fail, they break right through the hole. This was never a big problem, but I have replaced a few. Most of the failures happened a few years back, and was traced down to improper heat treat on that particular batch.
You are correct about where the shear areas are, the biggest culprit leading to breakage of the large hole pins is excessive dry firing.
"As long as there's lead in the air....there's still hope.."
Good deal, I appreciate it. Makes sense those thin sections on either side of the hole would have responded quite differently in heat treat than the rest of the part. So, indeed the swap occurring at the same time as the new mags began to be chambered was incidental.
I suppose if there is enough clearance between the bolt head stub and the bolt body, pure shear might not be as big of a part of the stress on the pin. The pin could be torqued into sort of an S which would put the bending stress at it's max right in the hole.
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