Amiral GC-20 Vipère
| Amiral GC-20 Vipère three-barrel rotary cannon | |
| Type | Rotary cannon |
|---|---|
| Place of origin |
 Oportia |
| Designed | 1748 AN-1750 AN |
| Manufacturer | Amiral |
| Produced | 1751 AN-present |
| Number built | 340+ (as of 1752 AN) |
| Unit cost | NAX€385,000 |
| Caliber | 20x102mm |
| Barrels | 3 |
| Action | Electrically driven rotary |
| Rate of fire | 750-1,500 rounds/min (selectable) |
| Muzzle velocity | 1,030 m/s |
| Effective range | 2,000 m (air targets); 1,500 m (ground targets) |
| Maximum range | 4,500 m |
| Feed system | Linkless feed; 500-round ammunition drum (typical) |
| Weight | 36 kg (weapon); 59 kg (with feeder) |
| Length | 1,520 mm |
| Primary users | |
| Platforms |
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The Amiral GC-20 Vipère (Alexandrian: "Viper") is a lightweight three-barrel rotary cannon developed by Amiral for helicopter and light vehicle applications. Designed to provide attack helicopters with substantial firepower while minimizing weight penalties, the Vipère entered production in 1751 AN and represents Oportia's first major domestic weapons development following the Fourth Euran War and the Vanie Accords of 1745. The weapon was developed primarily for export to Raspur Pact partners, with the Oportian Self-Defense Forces procuring a limited quantity for territorial defense helicopters.
Background
The Fourth Euran War (1745 AN-1747 AN) and the subsequent Occupation of Oportia fundamentally transformed the nation's security posture. The Vanie Accords of 1745 AN dissolved the former Oportian Security Forces and established the Oportian Self-Defense Forces, a constitutionally constrained military organization modeled on strictly defensive principles. Under the terms of the accords, Oportia renounced offensive military capabilities while retaining the right to territorial self-defense in coordination with its Raspur Pact allies.
The restructuring posed significant challenges for Oportia's defense industrial base. Amiral, which had supplied small arms and light weapons to the former Oportian military since 1707 AN, faced a dramatically reduced domestic market. The company's survival depended on transitioning to an export-focused business model while remaining compliant with the security framework established by the Vanie Accords.
Development
In early 1748 AN, Amiral identified an opportunity in the Raspur Pact market for a lightweight rotary cannon suitable for utility helicopters and light attack platforms. After-action analysis from the Fourth Euran War had demonstrated that existing rotary cannons were too heavy for many of the smaller rotorcraft operated by Pact members, limiting their effectiveness in close air support roles. Amiral's engineers proposed a three-barrel configuration that would sacrifice some rate of fire in exchange for substantially reduced weight, making installation feasible on platforms that could not accommodate heavier armament.
The design team, led by chief engineer Mathieu Renard, developed a weapon that weighed approximately 40% less than comparable six-barrel systems while retaining adequate firepower for the intended mission set. The three-barrel configuration simplified the feed mechanism and reduced power requirements. Development proceeded with technical consultation from Javelin Industries and ESB Susa, ensuring compatibility with helicopter platforms already in service across the Raspur Pact.
Prototype testing commenced in 1749 AN at facilities supervised by Raspur Pact observers, a requirement under the Vanie Accords for Oportian weapons development. The weapon demonstrated reliable performance across temperature extremes and sustained firing cycles. The Federal Forces of Nouvelle Alexandrie expressed interest in the design for its helicopter fleet, and a procurement agreement was signed in late 1750 AN.
The Oportian Self-Defense Forces subsequently authorized a limited procurement of the GC-20 for installation on maritime patrol and search-and-rescue helicopters assigned to territorial defense duties. This represented the first domestic-manufactured weapon system adopted by the Self-Defense Forces since their establishment.
Design
The Vipère employs an externally-powered rotating three-barrel design driven by an electric motor. The reduced barrel count compared to six-barrel designs limits maximum rate of fire but substantially decreases weight, mechanical complexity, and power consumption. The weapon offers selectable fire rates of 750 or 1,500 rounds per minute, allowing crews to balance ammunition conservation against volume of fire based on tactical requirements.
The linkless feed system eliminates jamming risks associated with conventional belt feeds in high-vibration environments and reduces ammunition weight. A typical installation includes a 500-round drum, though configurations vary by platform. Spent casings are retained within the feed system to prevent foreign object damage to rotorcraft.
The barrel assembly incorporates a quick-change feature enabling field replacement of worn barrels without specialized tools. Average barrel life exceeds 10,000 rounds under normal operating conditions.
Production and export
Full-rate production commenced in III.1751 AN at Amiral's facilities in Vanie. The company maintains production capacity of approximately 25 units per month, with the majority allocated to export orders. Under the terms of the Vanie Accords, all export sales require approval from the Raspur Pact's Committee of Euran Salvation to ensure compliance with alliance security protocols.
The Vipère's commercial success has been credited with stabilizing Amiral's financial position following the post-war restructuring of Oportia's defense sector. The weapon's relatively low unit cost and compatibility with a wide range of rotorcraft have made it attractive to Pact members seeking to upgrade their light aviation assets without the expense of procuring entirely new airframes.
Variants
- GC-20
- Standard production variant for helicopter installation.
- GC-20V
- Vehicle-mounted variant with modified cradle and ammunition feed for installation on light armored vehicles. Features increased ammunition capacity (750-round standard load). Development completed 1752 AN; initial orders pending.
Operators
| Country | Service | Platforms | Notes |
|---|---|---|---|
 Nouvelle Alexandrie |
Federal Forces of Nouvelle Alexandrie | Javelin H-1 Menace; Javelin H-7 Predator | Launch export customer; 280 ordered; deliveries ongoing from 1751 AN |
 Constancia |
Imperial Constancian Armed Forces | Various rotorcraft | 48 ordered; 1752 AN |
| Oportia |
Oportian Self-Defense Forces | Maritime patrol helicopters | 24 procured for territorial defense; in service from 1752 AN |
