I’m not sure where it started, but the “obrez” has gained a decent bit of recognition among gun folks (particularly gun folks on the internet). The concept is a Mosin-Nagant rifle with the barrel cut down to 4-8 inches and the buttstock lopped off, to make a concealable weapon in leiu of a proper pistol. Mosin rifles were fairly common and handguns much more difficult to obtain, so the obrez was a way for folks who needed a sneaky gun (be they criminals, partisans, or revolutionaries) to conceal under a coat. Recoil is pretty hefty, and accuracy non-existent, but they work well enough in close quarter. There are a number of videos on YouTube of folks shooting obrez’s (I really don’t know how to pluralize that…), and this one is a good representation:

www.youtube.com/watch?v=rNFsUvh078I

What is discussed less is that this sort of gun was made outside of Russia as well, using donor rifles other than Mosin Nagants. We found several on display at the Belgian War Museum in Brussels:

Really, there’s no reason to think this sort of modification wouldn’t have been used by partisans and guerrillas everywhere. You can see the wide range of barrel lengths, stock configurations, and overall workmanship.

Unfortunately (and somewhat ironically), in the US these legally must be registered as short-barreled rifles if they are made from pre-existing rifles. Only a bare never-used receiver could legally be the basis for an unregistered one, as it would then be considered a newly-made pistol and not a shortened rifle. Silly, I know, but that’s how the law is written.