The RW-53 'Mongoose' and the LBR-6 'Long Range' are the latest incarnations of their ancestor, the PiCUR revolver from 2024.
The Long Range is a 'simple update' of the PiCUR with a longer double barrel and with a more comfortable safety button. It is also equipped with a foregrip which can help handle the recoil of the gun caused by the new more powerful bullets developed especially for this gun.
The Mongoose is almost a totally new gun, but it kept the grip and the trigger from the PiCUR but it only has one barrel instead of two and it comes with a higher capacity magazine. The magazine design is very special, because in addition to the 53 rounds it contains the electromagnetic firing pin, the ejecton port and a battery for the mechanism of the firing pin. The whole magazine also works as the stock of the gun too.
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The PiCUR revolver:
https://www.artstation.com/artwork/39566v