I've got two Finnish MN's that have barrels with a reddish "plum" color to them
A "B" barrel M39
https://www.milsurps.com/images/impo...lm390021-1.jpg
https://www.milsurps.com/images/impo...lm390031-1.jpg
And a Finn 91/30
https://www.milsurps.com/images/impo...SC017691-1.jpg
https://www.milsurps.com/images/impo...SC017711-1.jpg
What is the gouge on the plum coloring? Any idea on what causes it?
Thanks