I don't know that I've ever seen a left handed firearm?
They exist. A the directorate deputy is a lefty, and has several of them. Bolt action, with the bolt on the left side, pump and semi-auto shotguns with the ejection port on the side, even AR-15 types with the ejection port on the left (those are more rare than the bolt actions).
My shotgun is ambidextrous, it ejects down and the safety is in the middle of the tang, suitable for left or right thumb.
I've seen one left handed bolt action .270. Course it wasn't out of box, it was made from wood and metal up by a gunsmith friend of mine.
Other then that I've only seen ambi-dex pistols.
Just about every firearm has a left handed model or doesn't need one since it's probably ambitextrous.
Even an AR-15.