It's funny to me that it's about the same size, or larger, than the tiny cannon.
Sadly, the tiny cannon video-
http://videosift.com/video/Miniature-tiny-cannon-using-real-gunpowder
-is dead/private.

Nice *engineering

Adding video to channels (Engineering) - requested by newtboy.

I'm calling shenanigans. I need video proof that the barrel has rifling if they are going to call it a rifle.

Maybe it is the world's smallest musket or shotgun.

Soon to be sold with the upcoming NRA Barbie.

Does it hurt though?

My family has a ton of these. Some are this small (some maybe smaller, I can't recall exactly), but probably don't qualify for whatever this is claiming as "smallest whatever". I don't know. Regardless, I only saw them a couple times as a kid, and never gave them much thought as anything more than "toys" that the adults played with. I know they could be fired, and maybe we fired one once(?), but it was more of an antique-heirloom kind of deal, rather than objects of regular use.
I wonder whatever happened to those...