The PX4 .45 takes a different hammer frame unit in order to have a different ejector. It is possible that the only ones who would know that are they that read this thread (ha, ha... no.. really ) https://pistol-forum.com/showthread....n-usage/page29 Post 287
The rumor that the stock trigger is plastic is incorrect. It is hardened steel framed coated in fiberglass reinforced techno polymer. The "All Steel" trigger is made by a 3rd party manufacturer and has a bad reputation. It is coated in Bruniton, which is a parkerized finish with an epoxy, polymer coating. So, either way you have a steel trigger and you are touching polymer.