Single six 50th anniversay question

[tal35]

I got this a long time ago and had never shot it. I opened it up to look at it and saw the mark in the pic on the 22lr cylinder. Is it normal?

 

[rugerguy]

No , it is not,that is a blemish,something got onto the cylinder and 'ate' (etched) into the surface, it could be about anything, sweat, drop of blood, a bit of soda pop....whatever....sorry
degrease and touch it up with a bit of cold blue, or just keep it oiled...........

 

[tal35]

It had rig put on it when I bought it, it looks perfectly round like a drill rod.