This is off topic because it doesn't involve Parkers.
With that said: I feel it's something we are all probably interested in judging by the amount of discussions here over the years about barrel failures & their causes.
Please keep in mind this is in no way shape or form scientific experimenting and no firm conclusions should be made from it, but it is a bit of an eye-opener never the less & should spark some thought & discussion. I just found it interesting with me being a dyed in the wool shotgun guy who loves shooting these old guns.
https://www.youtube.com/watch?v=S9NUs580-j0