What discoloration are you talking about, a dull gray color is normal.

 

It's not the dull gray color - it's like it's an almost yellow-brown color.

Maybe it's just normal for Yugo bayonets, as this is my first SKS, so I'm not very familiar with them.

 

M59's have a dull gray matte color. Here's a pic showing three M59's as compared to the bottom example of M59/66 with satin chrome bayonet finish.

 

...real nice Martin08!

 

I've used oven cleaner

on tough cases .



Fiveshot

 

There's an automotive/motorcycle cleaning product I've used for this sort of thing with great success over the years. It's called "Nevr-Dull". It comes in a can and looks like waste cotton fiber. It doesn't smell funky, contains no abrasives and won't "polish" the metal. It contains some sort of cleaning solvent that works amazingly well at removing petroleum-based residues, road grime and tarnish/corrosion from metal surfaces without damaging the metal's finish. I've used it on hard chromed (EAA's 'Wonderfinish'; Star's 'Stavel', car/MC trim and exhaust pipes), stainless and carbon steel (swords, knives and hand tools) brass, bronze and silver. It takes very little effort and does an A-1 job. It's a real whiz at taking the carbon deposits off of the cylinder face of stainless revolvers, too.

While I have also used it occasionally on small areas of "freckling" rust on blued and Parkerized guns without noticable damage or deterioration, I've always tried it on some inconspicuous area (like under the grip panel or stock ) first, just in case. The processes and formulae vary in these, so it pays to be cautious.

Doesn't cost a lot, and a can lasts for a long while.

 

try some Extra Fine #OOOO steel wool with WD-40

works great for cleaning