Yesterday I tried out a used SKS that I bought.

In a nutshell, the rifle will not fire a cartridge on the first attempt.

There is a pronounced dent in the primer of the loaded round, but not as deep as the dent on a cartridge that fire successfully.

A second attempt to fire the dented round will ALMOST always bring about the desired result.

The ammo is Wolf 122 gr Steel Case.

Out of about 15 cartridges, none fired on the first attempt, most fired on the second, although I carelessly did not keep carefull tally.

This morning, I lubed the gun with Break-Free.

I had 6 "dented" cartridges from yesterday, which I loaded into the rifle, then placed a fresh round on top.

The first cartridge failed to fire, the next 6 ran thru without a hitch, and when I single loaded the ejected first round, it fired as well.

I have owned a SKS in the past that ran completely glitch free, so I was somewhat surprized and disapointed at this.
I know mil-spec primers are harder because of free-floating firepins, but I still fully expected ther Wolf ammo to function, so I'm suspecting it's the gun itself???????

Today at lunch I disassembled the bolt and cleaned the pin and body well with steel wool, Break Free. No good.
Fresh cartridge FTF, racked the bolt and but the round back in, BANG!

I'm thinking maybe these Wolf primers are HARD.....

Advice appreciated!

Never rule out ammo when first attempting to diagnose a misfiring proble. Especially if the ammo in question is "Wolf". Try a "quality" brand.

Good advice.
As my regular shop is closed today, I'm going to grab a box of Winchester White box at Wally World on the way home.
That should shed some light.....

so, check firing pin spring... firing pin travel.. grease inside bolt... or other crap in side bolt.. becareful when you put bolt and firing pin back together

take bolt apart, pin out, spring out.. leave spring out, insert pin, and see how far it travels

If you have more than one SKS you can swap parts until a cartridge with the powder and bullet pulled with fire the primer with the muzzle into an old rug.

I have blown the firing pin out of a Yugo SKS with a case full of H110 and the 180 gr bullet jammed into the lands. [Don't try it.] The Albanian firing pins look very different, but still fit in the Yugo and work.

There were SKS rifles some time ago that would not fire or went full auto because they were so full of grease.

It appears the problem is the hard primers on the Wolf ammo. Winchester "white box" functioned perfectly.
I will still replace the trigger spring with a new one, because I believe it's still possible the previous owner may have clipped the spring a bit to try and lighten the trigger.
I do appreciate the advice from all!

I had the same problem with an sks of mine.I narrowed it down to not letting the bolt slam closed.Just pull it back and let it slam shut on a round and it goes off every time.Try to let it go down easy and it misfires.I havent had a misfire since doing this.
I also have wolf ammo,by the way.