Benelli is mainly known for its shotguns. They make some of the best semi-auto shotguns on the planet. Benelli also makes a few rifles, but not much more. It is a company with a focus. That doesn’t mean it never tried other guns. In fact, it tends to be creative with its other handguns. One of those is the Benelli CB-M2, Benelli’s first and only submachine gun.
The Benelli CB-M2 And How to Make an SMG
It’s surprisingly easy to make a submachine gun. That’s why we have the Sten, Grease Gun, and why Luty taught us all the potential for an at-home machine shop. Make it straight blowback, chamber it for 9mm, and if you’re fancy, make it a closed bolt.
Boom, now you have a submachine gun. Benelli could have very easily done that, but if that was the case, the submachine gun might have succeeded, and if it didn’t, we wouldn’t be talking about it anyway.
The Benelli CB-M2 did things differently.
What Made the Benelli CB-M2 Different
The ammo makes the Benelli CB-M2 interesting and worth writing about. Benelli partnered with Fiocchi to produce a unique cartridge for the gun. While the cartridge makes it interesting, it’s likely why the weapon failed. The cartridge is known as the 9mm AUPO or 9x25mm AUPO.
The 9×25 AUPO is an experiment in caseless ammunition. The idea behind caseless ammo gathered steam in the late 70s and 80s, but faded away quickly. The 9x25mm AUPO had no case, but the entire projectile was 25 mm long. The base was hollow, allowed propellant to be packed into the case, and used a ring of primer component. A fulminate plug sealed the system.
When fired, the rear portion holding the powder and primer detached from the projectile. This would make the ammo better described as semi-caseless than actual caseless ammo. The round moved at 1,200 feet per second and was essentially the same as a 9mm Parabellum ballistically.
This ammo design had issues, namely the potential to cook off. Cases act as heat sinks. Caseless ammo could create a simpler gun that theoretically wouldn’t need an extractor or ejector, which makes it cheap and arguably a little more reliable since there is less stuff to break. However, you need an extractor to clear a gun and fix malfunctions, which the CB-M2 had.
A Benelli SMG – What Else?
The CB-M2 does have a fairly unique look. It looks like a gun from RoboCop to me. It used a simple blowback operation, which is standard for the era. I’m surprised they didn’t go with a roller-delayed system to refine the weapon a little more, especially since you were selling it with a new, futuristic type of ammo.
The CB-M2 utilizes a long 40-round magazine that looks absurd. Between the magazine well and the trigger sits a cutout that acts as an ejection port. This is only used for fixing malfunctions and clearing the gun. Typically, brass-cased ammo expands, forming a gas seal.
Since the ammo had no case, the chamber had to be bored to allow the bolt to partially enter the chamber and create a gas seal. The firing pin struck downward on the case rather than on the ass end, which ignited the primer compound and fired the cartridge.
The gun’s rate of fire was 800-1000 rounds per minute. The barrel was 7.8 inches long, and the overall length, with its folding stock extended, was just a hair under 26 inches. The gun weighed 7.5 pounds total.
The stock appears to overfold. It seems to be a minimalist stock. It also appears that the grip has a grip safety. Benelli always used a lot of polymer in the construction of the gun. This helped save weight and likely made the weapon easier to produce. Overall, it looks neat and seems to be ergonomic, but it failed to attract any purchasers.
Why Did it Fail?
Ultimately, the Benelli CB-M2 failed to do anything new. The ammo wasn’t lighter or more useful than 9×19. It also introduced a new ammo type, which I’d assume was more expensive than standard 9×19. The gun failed to be simpler or offer any advantage to other SMGs out there. It didn’t do much or offer agencies any significant advantages.
It’s a neat gun, but I could see why it’s a hard sell.
Read the full article here
