This weapon is referred to as a '''Specs-docs only''' weapon. It cannot be normally found in the Mazes, and will only be available after completing the following requirements:
* Turn in the following specifications documents to the Proving Grounds engineer, at the Calfair Sector workshop:** [[Specs docs]]: ''#XR329 - Prototype shotgun magazine blueprints (Helical, 25-round capacity) ''* Bring a * A [[Benelli M2 Super 90]] or a '''M2 Super 90 Enhanced''', which will be used for conversion into this weapon (or the .** [[File:Parallar symbol.png|10px]]'''XM2XI "X-Shotgun" Mark 2500''', see below)
Upon completing the requirements listed above, the engineer will offer a brand new X-Shotgun will become available for sale at the Calfair Sector workshop from the Proving Grounds engineer, for [[File:Parallar symbol.png|10px]]'''1000'''in exchange. For this reason, this weapon is '''Rarity 7 (Unique)'''.
Please note that the Proving Grounds engineer is only available during the day shift (between 8 AM and 8 PM).