t1m0,

The finish looks similar to Springfield Armory's phosphate conversion (parkerization), but is more smooth and more uniform. This is why I've ruled out 'black oxide' (like a Remington 870 Express). Its the same finish (no surprise) that Ruger uses on their 10/22 barrels now.

Some parts are clearly blued (small bolt components), and the bolt is obviously bare stainless steel.

JYD #123 The great one formerly known as Architect.

I am now a fictional British television police officer (currently a Detective Sgt) at Thames Valley Station. My governor is Detective Inspector Fred Thursday and it’s 1969.