A friend just got a Turnbull case colored MK II with 10" bull barrel and was heading to the range today so naturally I got my 86 MK II 10" bull barrel out to join him. I don't shoot my MK II often, probably been 4-5 years since it's last outing so when I got home and began cleaning the pistol I was quite surprised when I realized my slide had turned PLUM. Has anyone else had their slides turn plum?