M1 carbine firing pin protection question

[INLAND44]

It could be bad business to leave something in a gun like that. In these matters I like to refer to the Army manuals and general practice. You clean a weapon after firing it and it gets put on a rack in an arms room, where if it is not regularly used, it will get regular maintenance. One thing that is never done is to leave anything in the gun or to cover/wrap it with anything.
There is a sealing procedure for long-term storage ('white bag' carbines for example). These rules came about over hundreds of years of using and maintaining weapons for immediate use, and I think they're all common-sense. What if you put a patch in a chamber and later somebody grabs the gun and loads it for immediate use? Technically there should be no wet oil in a barrel anyway for a racked firearm. It would ideally be inspected regularly, oiled and wiped.

[Anaspides]

Thanks Chris,
Your explanation is the simplest and therefore the most likely.
Thanks to all that contributed to this thread.
Cheers,
Peter