Well, I figured it out a while ago and am just getting to post it.
The bridge and the slide were worn (peened) where they contact and that was allowing them to move and forcing the screw to bear too much shear pressure and break. I got a nice used carrier and an upgraded bridge from GPC (and another new screw) and ran 50 rounds through it to be sure, customer says he’s put another 500 through it since, and is very happy. He also said it's seen many thousands of rounds before any problems since new, so here's to many more!!
Airsporter, yes it should fit nicely (and now does) but with the original peened parts it had some movement I was afraid was supposed to be there. I'm using all factory or new correct replacement parts.
Thanks for the help, always appreciated
Jarret