The CZ247 was developed for Czechoslovakia's post-war submachine gun trials, where it was pitted against the ZB47. It was a simple blowback 9x19mm SMG with a number of interesting elements, most notably the ability to fire with the magazine either vertical or horizontal. In theory, this made the gun more compact for use in a jungle sort of environment (vertical) or to allow a shooter to get much lower to the ground when shooting prone (horizontal). In practice, it really isn't very important, and requires a bit of extra complexity in the gun's design. The CZ247 also has a neat safety mechanism for preventing unintended firing and a stripper clip guide built into the stock (both of which would be incorporated in the vz.48 SMG that was eventually adopted).

When the CZ247 failed to win the military trials, CZ got government permission to sell it on the export market. A contract for 10,000 guns was quickly obtained from Egypt, but before the guns could be shipped the export permission was cancelled by the government. Czechoslovakia opted to support Israel in its declaration of independence in 1948, and the government decided to not send weapons to Egypt which might be used against Israel. This left the guns sitting in CZ warehouses, and the basically all stayed there for a few decades. Eventually most were sold to Nigeria in 1967 and Ethiopian in 1977 - and as a result they show up occasionally in African and Middle Eastern conflict zones to this day.

Thanks to CZ for giving me the opportunity to take this example out to film and also to shoot for you!

vz.38 SMG Video: https://forgottenweapons.vhx.tv/videos/vz38-smg-4k
ZB47 Video: https://forgottenweapons.vhx.tv/videos/zb47-4k