[refreshed]

Don't have a dog in this fight, just some definitions.

From Oxford Concise:

Shell: US. A cartridge.

Cartridge: A case containing a charge of propelling explosive for firearms or blasting, with a bullet or shot if for small arms.

Have a nice day!

[MineralMan]

"Don't have a dog in this fight, just some definitions.
"

Good for you. Some folks try to dismiss others' arguments based on their own personal definitions of firearms nomenclature. That never works.

Shell, cartridge, round. I'll bet none of these folks ask for a box of shotgun rounds or cartridges.

It's just a way to avoid discussing the real issues involved.

[flashbunny]

Yes, a case / shell / cartridge is a component of a round, not the round itself. The definition supports that - it is the case containing the rest of the compnents that go into the round - a 'shell' by itself is just something you pick up at the range if you're a reloader.

Taken with the correct definition, I'd agree with what's his name that you shouldn't carry with a shell chambered - you want an actual live round in there.