How is it possible for a Mossberg 590A1 firing pin to completely fall out?

[NoirFan]

First of all I am a beginner when it comes to taking guns apart so forgive me if this is a foolish question.

When working the slide on my 590a1, something in the receiver started to rattle. Shaking the gun caused a long pin with a knurled base to fall out of the shell port. I took apart the whole thing to see what it could be, and dimensionally the pin seems to line up perfectly within the "firing pin assembly". What I can't figure out is, how the hell did this thing fall out? I sure can't get it back in because that little pivoting hinged thing in the middle is preventing insertion from any angle.

Sorry for the imprecise language, but the subcomponents of the various assemblies aren’t labeled in my manual. The firing pin assembly is a solid block of metal with a small hole in the recoil shield (for the pin to strike the primer) and a larger hole in the other end (for the hammer to strike the pin), neither is big enough for the pin knurled base to pass through, so how did it come out in the first place? Anyone else had this problem?

Thanks

 

[Owen]

It goes in from the top, near the rear of the bolt.

Put the FP spring and the little washer between the locking lug and the rear of the bolt with the little washer to the back.

Insert the firing pin from the rear of the bolt.

Drive a the little pin in top to bottom. You should probably use a new pin.

 

[NoirFan]

Thanks for the info. I didn't even notice that little retaining pin near the rear of the bolt.