I used the firing pin protrusion tool just as intended. The firing barely touched the 75 notch. With this protrusion I had several light strikes today. I moved it out a half turn so I hope that this issue goes away next range trip. It still does not touch the 95 notch.

The fired cases look pretty much perfect. No neck splits, no shoulder splits or bulging. If the cases weren't steel they would be a picture of health for reloading.

Should I worry about buying a new spring or should I expect the deeper protrusion to settle the issue?

What type of ammo?

Matt

Russian Surplus

Your firing pin spring may have been cut down. Compare it to another one and see how long it is

Check the spring.

Other than that do the primers show any gas leakage ? I had a Can of 1980's Russian that had numerous rounds without flash holes.

If it's barely touching the 75 notch and not touching the 95 notch then moving it out some "should" solve the issue. As long as it still does not hit the 95 notch you are within specs, the old surplus ammo is famous for needing hard strikes to go bang.

I wouldn't be too worried about it Surplus is not exactly known to be the most consistent ammo. That will probably fix it as long as it  is in the go/no go for the protrusion Gage. Just make sure the pin is either flush or just below the surface of the bolt when it is cocked or you could have feed issues or a small chance of a slam fire.  If you keep having issues with it you may want to check the spring. It is pretty common for people to cut them down a little bit to make the rifles action easier, but it also causes lighter strikes. Last time I replaced one it was under $10 for a replacement spring.

With the mosin screwdriver tool, the tool should rock slightly when tested with the 75 notch. When checked with the 95 notch, it should fit flat with the bolt face and there should be space between the firing pin tip and the 95 notch.

Any more than that will usually have pierced primers, any less will be FTF.

Try different ammo or try replacing the firing pin spring.

Setting the firing pin between the 75 and 95 notch fixed the problem completely. Not one single issue today. What a blast.

Great news.  Told ya that's all it needed.