Ultra AC/20

(Redirected from Ultra Autocannon/20)
Ultra Autocannon.jpg
Ultra AC/20
Production information
Type ballistic (rapid-fire)
Tech Base Clan / Inner Sphere (IS)
Year Availability Clan = 2825 (CSV)

IS = 3060 (LA)

Technical specifications
Heat Clan = 7/shot

IS = 8/shot

Damage Clan = 20/shot

IS = 20/shot

Minimum Range Clan = 0

IS = 0

Short Range Clan = 1-4

IS = 1-3

Medium Range Clan = 5-8

IS = 4-7

Long Range Clan = 9-12

IS = 8-10

Tons Clan = 12

IS = 15

Critical Slots Clan = 8

IS = 10

Ammo Per Ton Clan = 5

IS = 5

Cost (unloaded) Clan = 480,000 C-bills

IS = 480,000 C-bills

Ammo Cost (per ton) Clan = 20,000 C-bills

IS = 20,000 C-bills

BV (2.0) Clan = 335[1]
42 (Ammo)[1]

IS = 281[2]
35 (Ammo)[2]


The Ultra AC/20 (also UAC/20) was the largest bore Ultra autocannon. Like all Ultra autocannons, it was capable of twice the rate of fire of a standard autocannon, doubling its heat output and—potentially—its damage. Only the Clan HAG 40 could match the sheer damage output of the Ultra AC/20. The only weapons capable of delivering more damage to one location were the heavy Gauss rifle and the experimental improved heavy Gauss rifle.


In the years between the Second Exodus and the beginning of Operation KLONDIKE, the nascent Clans began development of what would become the Ultra AC/20. Experimental prototype versions of this new weapon were used during Operation KLONDIKE in small quantities. The Clan prototype Ultra AC/20 available during this period had identical stats to the Inner Sphere Ultra AC/20 required additional mounting space and was more prone to jamming.[3]


The Ultra AC/20 was manufactured on the following planets in the Inner Sphere:

Aero-Model 4[edit]

Manufactured on Manufactured by Typically used in References
Kirin Kirin Orbital Works SJ-3 Xerxes [4]

Defiance Thunder[edit]

Manufactured on Manufactured by Typically used in References
Hesperus II Defiance Industries Demolisher II Blitzkrieg Hauptmann [5][6]


The Devastator was built to Clan specifications and had a caliber of 200 mm.[7]

Manufactured on Manufactured by Typically used in References
Various Various Hunchback IIC [8]

Model SH[edit]

The Model SH Ultra Autocannon was built to Clan specifications.[9]

Manufactured on Manufactured by Typically used in References
Sudeten Tokasha MechWorks Alpha Olivetti Weapons Kraken [10]

Type 10[edit]

The Type 10 was a 120 mm cannon.[11]

Manufactured on Manufactured by Typically used in References
Luthien Luthien Armor Works SM1 Tank Destroyer [11]

Ceres Huang Di[edit]

Manufactured on Manufactured by Typically used in References
Menke St. Ives Ceres Metals Industries Po [12]

Type 20[edit]

Brand Planet Company
Devastator Tamaron Ashton 'Mech Production Complex
Mydron Gulkana Yeffters Weapons Factory [13]


  • This article refers to a common object and addresses the object as a common noun. The preferred term is "Ultra AC/20" or "UAC/20" (except on section titles & table headings, where "Ultra Autocannon/20" is favored).


  1. 1.0 1.1 TechManual, p. 318, "Clan Weapons and Equipment BV Table"
  2. 2.0 2.1 TechManual, p. 317, "Inner Sphere Weapons and Equipment BV Table"
  3. Historical: Operation KLONDIKE, pp. 156-157, "Prototype Clan Systems"
  4. Technical Readout: 3067 p. 168
  5. TRO 3060 p.30
  6. TRO 3060 p.94
  7. The Price of Duty, ch. 8
  8. :Technical Readout: Clan Invasion, p. 38
  9. Technical Readout: 3067, p. 126
  10. Technical Readout: 3055, p. 122
  11. 11.0 11.1 A Call to Arms, Prologue
  12. Technical Readout: 3085, p. 36
  13. Technical Readout: 3050 Upgrade, p. 56