Here is a youtube I saw on another site. Don't know for sure if this is true or many facts, however I take gun safety very seriously. It appears to be accurate, in any case if you are purchasing a new BP firearm, check it out. This is a Pietta 1858 Buffalo New in the Box that has a cracked receiver.
https://www.youtube.com/watch?v=IzQ50r1gwH4
https://www.youtube.com/watch?v=IzQ50r1gwH4