I've never understood why a checked bag requires special circumstances if it contains a firearm.
A bomb in a bag is a cause for concern for the aircraft and the passengers. A firearm in a checked bag is... just a firearm in a checked bag.
Maybe I'm missing something. Or perhaps I need to watch some more Hollywood films where a bad guy somehow makes his way from the cabin to the cargo area. Yeah, that's what I need. More movies to shape my understanding of reality. Maybe I can run for office after I've seen enough of them.
A checked bag with a firearm in it is just a checked bag.
Now, I can see a possible threat from bag handlers who know of or discover a firearm in a checked bag. But that should require increased scrutiny on airport and airline personnel. Not on my inanimate bag and its inanimate contents.