J-1 semi-autonomous proton cannon

The J-1 semi-autonomous proton cannon was a long-range mobile artillery unit used by the Confederacy of Independent Systems during the Clone Wars.

Characteristics
The gun was operated by one B1 battle droid in a side-seat. It did not have an automatic reloading chamber, so shells had to be manually loaded by at least two battle droids before each shot. The shells used were powerful enough to deal considerable damage to an Acclamator-class assault ship or completely destroy a LAAT/i with a single hit.

The artillery piece, resembling a flak gun, was mounted on top of four legs, similar to that of Advanced dwarf spider droids, which allowed it to move around the battlefield, however, its turning rate was quite slow.

Usage
These units were used during the Battle of Ryloth in 21 BBY, where they fired upon the Republic invasion force. Three cannons managed to take down a ship within seconds.

Mace Windu ordered a retreat due to the damage the fleet was taking, as the cannon shells were able to penetrate the shields. During the liberation of the prisoners, Obi-Wan Kenobi took control of one of the cannons and destroyed all other cannons with help from Waxer and Boil before having to abandon the cannon due to incoming fire from an AAT.

The proton cannons would later be used during the Second Battle of Geonosis where they destroyed many Republic LAAT/i and LAAT/c gunships.

Appearances

 * Star Wars: The Clone Wars 7: In Service of the Republic, Part 1
 * LEGO Star Wars III: The Clone Wars
 * LEGO Star Wars III: The Clone Wars
 * LEGO Star Wars III: The Clone Wars