The ZB47 was developed at Brno as a contender for Czech military submachine gun adoption in the late 1940s. The Czech Army had technically adopted a submachine gun prior to World War Two (the vz.38; video on that is coming a bit later) but production did not begin before the arrival of German troops. After the war, the Army was eager to add a submachine gun to its arsenal, and the vz.38 was no longer a practical option as it was chambered for the 9x17mm cartridge.
The ZB-47 is chambered for 9x19mm Parabellum, fired from an open bolt, uses a simple blowback action, and does not have a semiautomatic setting – just full auto. In its infantry configuration, it has a fixed wooden stock with a thumbhole design and a 72-round (!) magazine fitted almost horizontally under the stock and barrel. A unique feed system pushes cartridges vertically up out of the magazine feed lips into a pair of feed ramps that pitch the round 90 degrees forward and into the chamber. The system is closest to that of the FN P90, although the cartridge rotating element on the ZB is built into the gun, not the magazine. The paratrooper variant of the gun has a collapsing metal stock, which shorted the overall length and also restricts its capacity to a 30-round magazine when the stock is closed. Rate of fire was reportedly a blistering 1200 rpm.
One challenge of this very long straight magazine was the slight taper of the standard 9x19mm cartridge case. In 30-round magazines this is not really an issue, but by 72 rounds the taper adds up to enough to cause problems stacking cartridges. Brno attempted to solve this by making a truly cylindrical version of 9×19, but the Czech military was (rightly) not convinced of its benefits and rejected it.
In the 1947 field trials, 8 Czech units were given examples of the ZB47 and other competitors. Five of those units actually reported favorably on the ZB; it looks like a very awkward gun to handle but actually isn’t in practice. However, the Army deemed it to have too many drawbacks, including the magazine reliability, poor accuracy, and bring judged too fragile. One more set of trials would take place the next year and ultimately the CZ model 23 was adopted. In total, just 62 examples of the ZB-47 were produced.
Many thanks to the VHU – the Czech Military History Institute – for giving me access to these two fantastic prototypes to film for you. The Army Museum Žižkov is a part of the Institute, and they have a 3-story museum full of cool exhibits open to the public in Prague. If you have a chance to visit, it’s definitely worth the time! You can find all of their details (including their aviation and armor museums) here:
https://www.vhu.cz/en/english-summary/
This was a very enjoyable video, and one I’d had a lot of expectation for!
The part about the tapered 9x19mm cartridge doing better from a curved magazine a la MP5 vs. the straight-walled cartridge really highlighted some of the design conundrums.
At 2:09-2:28 mark: “A Czech[oslovakian] P-90 a 1/2 century earlier and with 50% more magazine capacity…” Priceless!
Mr. M’Collum followers might further compare notes with this underside-mounted magazine where the cartridges point up, and then make a porpoise-like jump from the feed lips to the feed ramp to the chamber at approximately 90 degrees with the Canadian 1948 XP-54 prototypes too:
https://www.reddit.com/r/ForgottenWeapons/comments/cabx36/the_canadian_xp54_machine_carbine_with_trial/
Both of these prototypes–2 of the only 62 ever made!–date from before the communist coup d’etat and takeover of Czechoslovakia in 1949. A rate of fire of 1,200 rpm is mighty danged high, no? I’d note that the fixed stock version what with 72-rounds in the magazine is the capacity of the WWII-era Finnish Suomi and Soviet Shpagin PPSh41 guns, without the clumsy drum magazine. I half expected Ian to note not just the P-90 feed system, but also the crazy rotating chamber of the “Kraut space-magik” G-11 from Herren Heckler u. Koch, no? Certainly the Czecholsovakian Holek brothers had a much simpler means to effectuate the feed of the cartridges than on ze German Cold War-era wunderwaffe, no?
I was impressed by the marker plate in the magazine for the round count versus the much more typical witness holes or transluscent polymer magazines more common to our era. Interesting safety that locks the bolt in either the foreward/un-cocked or backward/cocked position, and a good safety feature on a sear-fired open bolt gun. The gun can’t be disassembled with the magazine in place, which was also interesting to me. A tube gun open bolt SMG is obviously way simpler to make and manufacture and probably maintain, but I could see why 5 in 8 guinea pigs in the Czechoslovakian army thought this was a neat gun. I particularly liked the collapsing-stock version with the ability to use full-size 72-rd. magazines when the stock was extended, but Ian did not how atrocious the stock would be from the firer’s position in terms of cheek weld and other handling considerations.
The Czechoslovaks seemed to have found a “sweet spot” in 9x19mm cartridge capacity with the slighty tapered 40rd. stick magazines for the samopal 23s and 25s that the communist government dumped in revolutionary Cuba after 1960. I recall Ian didn’t care much for that SMG, but cetainly the little 8-rd. stripper-clip magazine loader, the use of a portion of the telescoping bolt as a wrench to remove the barrel nut, and other touches are interesting.
With a different new-fangled cartridge, I’d wager this old ZB47 prototype could serve as a basis for the long-sought, never seriously mass-issued “PDW” that occupies so much online gun banter, but remains yet another will-o’-the-wisp since the PDW avant la lettre, the U.S. M-1 carbine.
As bizarre as it may be to contemplate: Does one wonder in looking at the firing grip of the ZB47 prototype if the Holek bros. were familiar with the 8x22mm Nambu Shisei-ni-gatu Kikan-Tanju experimental “Model 2” of imperial Japan?
https://en.wikipedia.org/wiki/Experimental_Model_2_submachine_gun
What a fertile mind… Hats off…
Is there a video on the Vz38? If not, are there any surviving examples you can review?
Ironically, the main drawback when you use tapered cartridges in a long straight mag is that the cartridges can start to nose downward – exactly what you need to make them do in a P90 or similar magazine.
From the written commentary **in this very post**:
“video on that is coming a bit later”
Ah, thanks and sorry, skimmed the written summary while doing too many things at once.
Oh yeah, “happens!” LOL!