Anybody has done this? What's the advantage? And where to get all the parts in RP, how much ballpark cost? Is it worth the cost of the upgrade? The following is a list of parts that will be replaced for the Firing Pin System Upgrade: Trigger w/Trigger Bar Extractor Firing Pin Firing Pin Safety Firing Pin Safety Spring Spring Loaded Bearing Please note that all of the above parts have to be replaced, in order for the gun to function properly. If you are unsure if your gun has had the upgrade - consult a Glock Certified Armorer. An indicator to whether the upgrade has been accomplished is to examine the firing pin (see graphic below).