I just got a project rifle . What causes a polished steel blue to look Purbleish? I have seen this before. It looks like crap and I dont like polished ,mirror shine blue jobs anyway. The reciever is the purbleish color where its polished but the polished barrel is black.
Luckely the serial , model ,etc. stamps look pretty crisp, not rounded.
Rick

I've only read a little about this condition. The last thing I read on this type of discoloration is that it happens to investment cast metal, like Ruger uses in their guns. I don't recall if they have ever pinned down the exact cause. Some collectors really like it and think it is unique, others don't. After reading the article, which really didn't give much information, I realized that I'd never seen any guns that weren't investment cast that turned that purple color.

I dont thing this is investment casting . Its a 1941-'47 remington model 720 enfield action

I read somewhere that it's from silicon in the steel. I saw it in reference to the investment cast Rugers. (My M77's receiver's purple.)

FWIW,I was told by the guy at Hotflash Refinishing Services that it is due to various minor impurities that exist even in "pure" steels. He said it is quite common in military guns. I have a few sporterized military guns that have a brownish purple cast to the bluing. Different parts from the same gun do not always come out of the blueing tank the same color either.

I'm not an expert, but, my understanding is that nickel steel receivers will sometimes turn redish colored when the bluing solution was allowed to get too hot. I have hotblued several p14 actions and some turned reddish and others didn't. Some of them only parts of them turned the reddish color. I would imagine that the Rem. 720 is also made of nickel steel being an offspring of the 1917 and P14 enfields. Just my opinion, Roger.