This is the first in a series of posts about various items (weapons, cars, etc) that combines fact with sardonic-ism. This will usually compare two things that are generally held to be horrible, and, using research, determine which one is actually worst. These posts were also inspired by the "World's Worst" books, namely World's Worst Cars and World's Worst Weapons.
Now, here's what are widely held to bet two of the worst automatic weapons ever designed, the French Chauchat from World War I (and also made appearances in World War II, the Spanish Civil War and even the Vietnam War), and the Italian Breda Model 30, used mostly in World War II (also in other conflicts beforehand, such as the Spanish Civil War and the Italo-Eithiopain War).
To begin with, the Chauchat machine gun is widely held to be one of the worst firearms ever designed--no book on crappy weapons is complete without it. However, more recent research has shown that, perhaps, it wasn't that bad.
First, the elephant in the room. The Chauchat wasn't no where near as good as the Browning Automatic Rifle. But then again, few weapons back then of that type were. It was cheap, relatively jam-prone, made in a rough-shod manner, and chambered in 8x50mm R Lebel--a round far from ideal in use in self-loading or automatic weapons.
That all being said, the Chauchat had some positive virtues. It was made mostly out of sheet metal stampings and drawn tubing--manufacturing processes that wouldn't become common until World War II over 20 years later. This made it easy and inexpensive to make--something that the French desired, as they needed/wanted as many machine guns as they could get, and as quickly as they could possibly get them. This also lead to well over a quarter of a million Chauchats being made by the end of World War I. Hence, it was the most produced automatic weapon of the entire conflict.
The fact that the Chauchat survived in used in some numbers reportedly until the Vietnam War does show its longevity, in spite of its flaws. And yes, the Chauchat was jam prone. But in truth, this was due to two things: overheating and its magazine.
The Chauchat tended to overheat if more than 300 rounds was continuously fired though it. This resulted from the aluminum barrel jacket expanding and catching on the steel outer body of the weapon. This usually only took a few minutes of cooling to remedy, or by dumping water on the barrel assembly. As the Chauchat wasn't really designed for sustained fire, this was actually seen as an acceptable flaw.
A much bigger flaw was the Chauchat's magazine, which was a 20 round detachable crescent shaped device with large holes cut in the sides of it. The cuts were intended to allow the user to check the amount of ammunition he had left. Of course, this also meant that junk and detritus could easily find its way into the mag and coat the mag with mud, dirt, dust and the like. With the trench warfare that was common in France and Belgium during World War I, this was easy to find, and the holes in the mag wasn't a desirable feature for obvious reasons.
Also, the 8x50mm R Lebel round, a severely tapered, rimmed cartridge, was ill suited to automatic weapon use. At the time, though, it was the standard French Army rifle and machine gun round, so the Chauchat's designers had little choice but to use it for logistical reasons. In fact, the 8mm Lebel round wouldn't be replaced completely until after World War II, though the French designed a successful 7.5x54mm rimless round of more conventional shape in the 1920s, and machine guns and rifles that went with it.
In short, records do show that the magazine was responsible in one way or another for 75% of the Chauchat's jams in combat and on training ranges.
As far as how it worked, the Chauchat used a variation of long recoil inspired by the Remington Model 8 which was designed by John Browning as a hunting rifle. Interestingly, Browning also designed the BAR, which was a gas operated weapon whose basic mechanism is used in the present day and long running FN MAG 58/M240 machine gun family. The breech on the Chauchat, like the Model 8 (and like, for example, the gas operated M1 Garand rifle) was locked by a two lug rotating bolt.
Though it was flawed, it was the French World War I equivalent of the British World War II Sten SMG. It was cheap, available, could be made quickly and cheaply, and for that reason it appealed to the French Army and gave decent account of itself at the end of the day. Granted, the modern FN Minimi/M249, FN MAG/M240 and even the HK416F rifle are much better weapons than the Chauchat, but that's also comparing weapons of different eras and hence is an apples to oranges comparison.
https://en.wikipedia.org/wiki/Chauchat
Now the Italian Breda Model 30. This weapon was the result of an effort dating back to late World War I to get a light machine gun that was in a rifle caliber (in this case the 6.5x52mm Carcano round) and more portable than the Fiat Revelli 1914 tripod mounted medium machine gun.
First, there was the SIA 1918, which was a relatively light weight machine gun mounted on a light tripod. Though a reasonable weapon in some ways, it was felt that there was clear room for improvement. Though a line of development in the 1920s with the Fiat and Breda companies primarily, the Breda Tipo 5 was developed as a direct predecessor to the Model 30.
The Tipo 5C was mounted on a light tripod with spade grips and a thumb trigger (though it had a conventional buttstock). There was also a transitional Tipo 5G which had a conventional trigger and pistol grip, and stood on a bipod. The mass produced Model 30 was the productionized version of the Tipo 5G.
The items that all versions shared in common was they were overmachined and complex to make, and were inefficient and impractical in service.
All versions operated though a short recoil mechanism with a very short recoil stroke. As such, it's been described as a blowback or delayed blowback weapon, though it in reality used a fully locked breech, as ineffective as it was. The recoil stroke rotated a locking collar that unlocked a five-lug bolt (which didn't rotate, the locking collar did, though).
All versions of the Tipo 5/Model 30 were fed from a 20 round semi-fixed box magazine. Typically, the magazine was reloaded using a 20 round horseshoe shaped charger, though it could also be reloaded with loose rounds. The theoretical advantage of the mag design was that the magazine lips were machined into the receiver and less prone to damage.
However, the reloading process was slow, and though the mag could be completely removed, this was usually done during field stripping. Also, should the mag be damaged, the gun could be put out of action until the mag could be replaced, which was problematical on the battlefield. Also, like the Chauchat, the mag had a cutout to check the contents, though (especially in North Africa in World War II) this merely tended to allow crap to find its was to coat the rounds, which isn't a good thing.
On top of that, due to poor primary extraction (the initial extraction movement that unseats the round from the chamber to ease overall extraction), the Breda used lubricated ammo. This as achieved though the use of a cartridge oiler. Given what I just mentioned about the magazine, this wasn't a good feature, as the oil tended to attract said dirt and dust and make a nasty slurry in the chamber of the barrel and other parts of the gun.
All and all, in short, a horrible weapon.
https://en.wikipedia.org/wiki/Breda_30
So, which is worst:
This is actually a pretty hands down answer from my POV. The Breda Model 30 is by far the worst of the two. The Chauchat in a lot of ways wasn't very good, that much is obvious. But it has some excuses to be not great, and it's not quite as maligned as accepted urban legend makes it out to be.
The Breda Model 30, though, is way to complex for its own good. It was more difficult to make than say a BAR, or a Bren/Vz 26 LMG of the period, both of which were pretty intensive and somewhat expensive to make. But for that difficulty of manufacture, the Model 30 was junk. It was more jam prone than the Chauchat, used oiled ammo (as pointed out, generally not a good thing) and was slow to reload.
Reports from the World War II era seem to indicate that the Model 30, especially one that wasn't in top condition, was so slow to reload and prone to jamming that a US soldier with a M1 Garand semi-automatic rifle often could produce a higher volume of fire than an Italian Breda 30 gunner could. That's not to knock the Italian machine gunner, as it wasn't his fault that he was saddled with such a pile of crap.
In spite of that, a Chauchat gunner and a Breda Model 30 gunner did have one thing in common: it was accepted that they were among the most dangerous troops to come across at the time they were faced. During World War I, man portable automatic were a rarity, except for the Chauchat until late in the conflict. Hence, for all its flaws, the Chauchat did have some right to be feared by the enemy because it was at least man portable when such weapons were far from common.
In the case of the Breda Model 30, it tended to stand in for semi-auto rifles or even submachine guns. The Italians didn't field semi-auto rifles in any notable numbers during World War II (ironically, the Italians adopted the M1 Garand following World War II, even license building them and using the M1's design to develop the Beretta BM-59 and some design elements of the M1 influenced the Beretta AR-70 and AR-70/90 5.56mm assault rifles). Also, until late 1942, submachine guns weren't common in the Italian infantry units. Even though the Beretta MAB 38 family were commonly used by Italian paratroopers, the Carabineri (the Italian Armed Forces civil police agency that's still a part of the modern Italian Armed Forces), commando units and the Blackshirts, they weren't commonly issued to Italian infantry until late 1942/1943.
That all being said, the Breda Model 30 is probably the worst, most craptastic automatic weapon ever designed.
For further reading on the Chauchat or Breda Model 30, check out the Forgotten Weapons website and YouTube pages.