Mid to Late War SA Parkerizing

[ROCK]

Does anyone have an idea of when SA switched over to the flat, light grey parkerizing seen on late war rifles? Original finish on rifles in my collection from 8-44 to 6-45, have this identical color finish. I'm wondering when they started with this truly distinctive finish change.

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[RCS]

Back in the mid 1990's my friend found a M1 rifle at estate sale in a remote Wisconsin area. He called me and asked if I was interested, I told him to buy it for me. The only other guns were a 22 RF and shotgun which I was not interested. When I got this M1 rifle, it showed alot of service, but all the parts were correct for April 1944, nothing was changed-out. I feel certain this was a bring back from WW2 by a veteran. The color is a light gray which I believe to be the original color.

I did test fire it at 100yds which some different lot of AP & ball, everything worked without an problems, bore is bright but T.E. is over 4.0Attachment 121225Attachment 121226Attachment 121227Attachment 121228

[Rockandroll]

The dark charcoal lie finish is magnesium phosphate. The light gray finish is zinc phosphate. When and why the change over, don’t know. My issued M-14 was magnesium phosphate.

[Brian Dick]

I think they used manganese phosphate at SA which is a darker grey color. The color may be lighter when the bath gets weak. If you look at original Winchester phosphate finish, you'll find it's a very light grey zinc phosphate bath that they used. You can usually tell the original finish as it was applied over smooth metal. Later rebuilds were sand or glass bead media blasted prior to refinishing, the texture is different and nowhere near as smooth.

One of my CMP purchase M1 Rifles is a post WW2 H&R and they were done in manganese as original but mine's an arsenal refinish redone in light grey zinc. It's a lovely rifle and still matching throughout as received. Even the stock is H&R but it sports an AN inspector's mark and was obviously refinished at Anniston. The metal is pretty smooth but has obvious texture from bead blasting. I'm not sure if the Armorers at CMP changed any parts but it's got the correct factory parts throughout which is very uncommon for any military rebuild.