I hear there’s a little blue pill you can take for that
The prop used for Jon Snow’s Valyrian steel sword when sheathed works just fine in non-action scenes. However, when he hurriedly mounted his horse in the most recent episode, The Battle of the Bastards, it certainly didn’t behave like an object forged from an incredibly strong metal whose recipe is lost to history.
Follow the link for animated GIF goodness.
[Joe deVilla/The Adventures of Accordion Guy in the Twenty-First Century]