DAB, Good info again, thanks. I have not handled a hammer spring for a model 92, but I understand that they are 3 coils longer than one for a PX4. If that is the case, the 12# 92 spring would deliver more than 12#s in a PX4 because of increased compression.
This is a good question for Mr. Langdon, and an opportunity to attempt to try tagging him (again). Though, I see that Tom_Jones tagged him for us.
@LangdonTactical (hopefully he will understand all the tagging is not nagging, but learning how to tag!