It had always been a bit stiff since I bought it a dozen years ago for $200.  Fired it sparingly.

After the latest FTF, I took it apart.  The firing pin was difficult to remove.  When it did come out, it was noticeably bent.  It did not get that way from removing it.  It lifted from its slot, but not without a little bit of dental pick encouragement.

How did it get that way?  Precedes my ownership of it.

As the owner of a Marlin 39 I can't see how it would get bent in use. I'm guessing a ham fisted attempt at disassembling earlier.

The Marlin 39 series has one of the most sturdy .22 firing pins ever used.
They don't bend easily, or under any kind of normal use.

As above, I'd suspect "miss-adventure" by a previous owner.
If the pin can't be straightened, buy a new exact replica from Wisner's........

http://www.wisnersinc.com/model/marlin-lever-action-rimfire/

This was the fist attempt by me to removed the carrier let alone the firing pin.  I ordered a new one.

AGIMW, I can’t imagine the reason or means by which a person could bend the dang thing.

It could be a replacement firing pin that wasn't properly fitted. I have one that I unknowingly purchased with a broken firing pin, which is probably the reason it was for sale in the first place. The replacement firing pin from Wisener's is easy to fit and works perfectly. It's about 30 minutes worth of file work if you take it slow. If you use a really aggressive file you could probably have it up and running in about 5 minutes.

That makes sense.  I don't know how you would bend the firing pin without a vise, pliers or hammer.  However, since they get pretty hot in the manufacturing process (if they are milled) it could have simply warped.  Or if stamped out, bent then.

I ordered one from Brownell's but their email suggests I won't get it any time soon.  In the meantime, I am slowly filing the bent one until I can get it to move in the slot freely.

If you're not the original owner, it may just be a firing pin that someone tried to replace and didn't know how to file something flat. They are cast pieces originally. It would probably break before actually bending. All the "milling" is done by hand or by file. The 39A firing pin is actually pretty easy to break based on the design. It's definitely the weakest link in the gun other than the ejector. You really have to count your rounds to keep from firing on an empty chamber.

This is one of those rimfire firearms that doesn't have any wiggle room when it comes to dry firing. If there's no cartridge in the chamber the front leg of the firing pin slams into the bolt and the tip contacts the edge of the chamber when the hammer falls. Do this enough times and it will break the front off. You can using a round file to relieve the 90 degree angle where the front leg meets the end of the firing pin - that in theory would distribute the force of the shock a little differently. Also, be careful of the overall length. You have to file the end length exactly flush or just a TINY amount short of flush with the back of the bolt. About the only other critical dimension is the front side of the front leg I was referring to earlier. Too much metal will give you light primer strikes, too little will have you hitting the primers too hard and/or contacting the edge of the chamber. Also, the firing pin should slide back and forth in it's slot freely. If it sticks anywhere it can slow the velocity down and give you light primer strikes.

When I replaced mine, I managed to find a new, never fitted factory replacement part. I also picked up a couple of the Widener's. The Wisener's was much easier to fit.