I didn't know there was a difference in the dimensions of the 9mm vs 357/40/45 GAP firing pin until today. From www.glockparts.com "Are the .40 cal. firing pin and the 9mm. firing pin really different? I can't tell the difference. Yes, the .40 cal. S&W firing pin is .015 in. longer than the 9mm firing pin." Thought I would share a picture of the ID marks the current parts have from my 2012 19 and 23. My 2005 G17 has no mark.