I've come across something on my new GP100 that I've never seen before, but maybe some of our more Ruger knowledgeable members have. The barrel stub/forcing cone area of my GP100 is faceted where it screws into the frame. Appears to have had 6 easily visible flats machined into it. I've owned lots of revolvers, and my share of Rugers, but have not encountered this before. But this is the first GP100 I've owned, so perhaps this feature is common knowledge to some of you guys. Is it?