Well, what more can I say. I WAS WRONG! After a couple of fellows responded that possibly it was a MIM part, I took one of them apart again and checked with a magnet. Yup, it's steel. It was so smooth and black and shiny I immediately assumed plastic. So, that's what I get for being too quick on the trigger, pun intended, plus being paranoid about the use of crap material in some of the new guns. I have had a lot of faith in S&W for about 50 years now and keep expecting the worst. Naughty me.