|Group: Ranged Weapon|
|Weight||1,000.0 kilograms (towed)|
|Ammo||20mm bullet, x200 round drum|
"Auto-Cannon:" A linkless feed, fully automatic weapon, the auto-cannon fires a 100.0 gram round at velocities of 1,200.0 meters per second with a practical rate of fire of 200 rounds per minute. Ammunition is provided in 200 round drums, two of which may be attached to the weapon at any one time. Two different ammunition types may be used, one in each drum, and drum selection may be changed anytime after active firing. Replacing an empty ammunition drum requires more than a minute. If a loader is present, this may be done while the weapon is being fired from the other drum. Ammunition provided includes HE, and 20/9 mm discarding sabot. Every tenth round in an HE drum is an incendiary round. The weapon fires ten round bursts, up to five of which may be fired in under a minute. Bursts may be directed at different targets within the weapon's arc of fire. 
The weapon is available in three different configurations: turreted, towed, and pintel mount. The turreted version has a 180° arc of fire while the other versions have a 90° arc of fire. Turreted and pintel mounted weapons must be mounted on vehicles, while the towed version is provided with a cruciform platform for firing emplaced. 
Length: 1,500.0 mm. Weight, unloaded: 400.0 kilograms (turret), 300.0 kilograms (pintle mount), 1,000.0 kilograms (towed). (200 round drum, 100 kilograms). Base price: Cr12,000 (turret), Cr10,000 (towed), Cr7,500 (pintle mount). (200 round drum, Cr1,000). Extreme range: 2,000.0 meters (…except pintle mount, 1,000.0 meters). Tech level 8.
- ("Note:" A variety of more primitive automatic cannons ranging from 20mm to 60mm are available beginning with tech level 6, generally more bulky and less effective.) 
History & Background (Dossier)
The first autocannons were simply upsized machineguns. Earlier cannons were less succesfful and were often used as wall guns on fortresses. As aircraft developed, the autocannon became an ideal weapon for smaller aircraft to use to shoot down larger aircraft. As the technology for internal mechanisms improves and becomes more reliable, more sophisticated, faster-firing autocannons become possible. Multi-barrel rotary cannons are also an offshoot of autocannon technology. A variety of feed mechanisms have been devised for such weapons from drums to belts to chain-linked ammunition and more. The weapons remain in active service in a number of roles until the advent of gauss and energy weapons, which supplant them once perfected. 
Auto-cannon begins development around TL-6 as the automatic fire version of a small breachloading cannon. By TL-8 they are filling a role between the 10mm-15mm Heavy Machine Guns and the larger artillery peices. These autocannon are used in a variety of roles, from helicopter and fighter armament, to APC armament and anti-aircraft guns. By TL-10 they have been largely supplanted by Gauss Weapons, laser weapons and later by rapid-pulse plasma or fusion guns.
Selected Auto-Cannon Models
- TL-4 Wall Gun
- TL-5 Wall Gun
- TL-6 Auto-Cannon
- TL-7 Auto-Cannon
- TL-8 Auto-Cannon
- TL-9 Auto-Cannon
- TL-10 Auto-Cannon
- TL-11 Auto-Cannon
- TL-12 Auto-Cannon
References & Contributors (Sources)
- Bryan Steele. Mercenary (Mongoose Publishing, 2008), 38.Frank Chadwick. Mercenary (Game Designers Workshop, 1978), 38.
- Jim Cunningham. "The Armory: Mercenary Support Weapons." High Passage 3 (1982): 38. (Illustration)
- Marc Miller. Imperial Encyclopedia (Game Designers Workshop, 1987), TBD.
- Greg Porter. Emperor's Arsenal (Imperium Games, 1997), TBD.
- Traveller Wiki Editorial Team
- Author & Contributor: Lord (Marquis) and Master of Sophontology Maksim-Smelchak of the Ministry of Science