It's Armémuseum in Stockholm. Temporarily closed though. :/
They have a Digital museum where you can search for objects though. I've searched for 'Gatling' in the link. Common names like musket/musköt have to be in swedish.
Fuck. They're evolving.
From Musket To Metallic Cartridge if you like firearms history.
Turn it into an abomination
Rebs with Kalashnikovs
Imho, a gaypink concealed carry gun would make it more likely to be able to claim self defence if you shoot someone in self defence.
It might also but you a few extra moments when your attacker goes "What the fuck is that gay thing?"
"Say hello sailor to my little friend."