i have a blued ruger police service six, it had just a small bare line of metal showing behind the turn line on the cylinder. i messed up big time today, i tried g96 cold blue. big mistake it took my bluing off my cylinder. now i have thumbnail size blotches of bare metal all over the cylinder. i don't know what is in it but it ain't good. now it looks like as much as i like this gun i can't live with it like it is and i need a handgun so sending it off is a no go either. gonna post it for sale soon, if i could kick myself i would. i wished i had left it alone but thats seems to be my luck lately. the g96 is bad stuff to bluing for some reason.