I found two videos. One is a video from YouTube:
【Laipublications】Full-auto firing of the FNAB-43, with slow-motion footage - Bilibili https://b23.tv/n9MW7l6
The other is what it would look like if the rate of fire from this video was implemented in the game:
【Enlisted】If the FNAB-43’s rate of fire was historically accurate… - Bilibili https://b23.tv/tZJjMQr
It feels like it could go toe-to-toe with the PPSh-41 (box magazine), similar to the PPS-42.
This would give Germany the ability to fight against the Soviet BR3 weapons.
This is exactly the kind of BR2 weapon Germany needed.
I’ve checked both the original YouTube video and the creator’s website.
The author states the FNAB-43 has a lightweight delayed-action mechanism, a short bolt travel (100mm), uses higher-power Beretta 9mm ammunition than standard 9mm, and has no rate limiter, resulting in a very high rate of fire.
As for why it doesn’t fire at 400 RPM, the author speculates it’s because the ammunition used was less powerful than the original Beretta rounds, causing the delay mechanism to behave differently from the original design. But he thinks this explanation is unreliable, and the 400 RPM figure is just a rumor.
The author also mentions that the “effective” weight of a lever-delayed action is not just the bolt carrier plus bolt; it must be multiplied by the lever delay ratio. Using the FAMAS lever delay ratio, the effective weight in delayed mode is roughly equivalent to an 853-gram straight-blowback bolt—slightly heavier than the Sten, but not slow enough for 400 RPM.
He also notes there are two versions of the FNAB-43: an early model and a later simplified variant.
Additionally, a YouTube user named @ekal4549 commented that his FNAB-43 fires slightly faster than 400–500 RPM, around 600–650 RPM.
Combining this information, I personally believe there are several theories for why the FNAB-43’s actual rate of fire differs from theory:
- The FNAB-43 is extremely rare; few people have actually fired it. Someone assumed a delayed-blowback submachine gun would fire slowly, and the rumor spread. This is the author’s view.
- The FNAB-43 uses a relatively precise lever-delayed system. All such semi-delayed blowback weapons share a flaw: they only function reliably with specific chamber-pressure ammunition and require tight tolerances for the delay mechanism and recoil spring. Any mechanical mismatch causes malfunctions. The shooter who reported 400 RPM likely used ammunition with incorrect chamber pressure or an overly stiff replacement recoil spring.
- Only 7,000 FNAB-43s were produced, and it was not widely adopted by the military. Rate of fire likely varied per batch, ranging from 400 to 800 RPM.
In my opinion, 400 RPM is completely impossible. This action cannot delay locking for that long. I personally lean toward around 800 RPM. Any lower rate is due to improper repair or maintenance.
Documentation on this gun is extremely scarce; almost no reliable historical data exists. Basic tests—Italian military trials, round count, malfunctions, 100-meter dispersion, rate of fire—are all missing. Even the original source of the 400 RPM figure is unknown. That number even fooled Ian.
I hope one day CR Arsenal or FW can find a shootable FNAB-43 and release a proper range test video.
If someone can find or reload modern ammunition matching the specifications of Italian WWII military ammo and fire it from a well-preserved specimen, that would give the true designed rate of fire. Unfortunately, the gun is so rare that only one shooting video exists online