Oh, you've gotta love it. ABSOLUTELY HAVE TO LOVE IT.
Went and watched the referenced YouTube, done by the most gifted and skilled kitchen table expert >> Expert - Noun > Ex as a has been and Spurt - a drip under pressure.
After his careful and "expert" ministrations, that shotgun is actually worn out. Wobbles at the hinges. Then ..... Then ..... THEN >>>> following his careful, expert and cheap chamber honing job, the hulls wouldn't extract. WONDERFUL!!
I almost croaked laughing so hard. Just a shame he managed to ruin a perfectly good shotgun. What a Putz.
Coffinmaker
PS: Before I retired, if a customer admitted to owning a Dremel, I doubled the repair estimate without even looking at the gun.