Something interesting about the mighty GAU-8/A Avenger gun is that is mounted just left of the A-10 centerline.
Installed in all production A-10 attack aircraft as well as in both YA-10As (in which was retrofitted replacing the Vulcan cannon originally installed), the seven-barrel GAU-8/A Avenger 30 mm Gatling gun is the primary Warthog weapon for close air support (CAS) missions.
The GAU-8 itself weighs 620 pounds (280 kg), but the complete weapon, with feed system and drum, weighs 4,029 pounds (1,828 kg) with a maximum ammunition load.
It measures 19 ft 5 1⁄2 in (5.931 m) from the muzzle to the rearmost point of the ammunition system, and the ammunition drum alone is 34.5 inches (88 cm) in diameter and 71.5 inches (1.82 m) long.
Power for operating the gun is provided by twin hydraulic motors pressurized from two independent hydraulic systems.

The magazine can hold 1,174 rounds, although 1,150 is the typical load due to the 575 round capacity of the loading cart.
Muzzle velocity when firing Armor-Piercing Incendiary rounds is 1,013 m/s, almost the same as the substantially lighter M61 Vulcan’s 20 mm round.
Something interesting about the mighty Avenger is that is mounted just left of the A-10 centerline.
Lynn Taylor, A-10 Pilot, Joint Firepower Course Instructor, Air Liaison Officer, explains why on Quora.

‘The barrel assembly of the GAU-8 Avenger is mounted just left of the aircraft centerline. However, the bullets exit the firing barrel when it is in about the 7 o’clock position of the barrel assembly (viewed from the front).
‘That position corresponds with the centerline of the aircraft. So, while the whole gun may be offset, the bullets still fire from dead center.
‘If you want to get even more detailed, the firing position is below the horizontal center of mass, so the nose wants to pitch down when the gun fires. There is a stability augmentation system that engages to help prevent that dip while the gun is fired, keeping the nose on target.’
Taylor concludes:
‘That system can be disengaged in the event you need to strafe an area instead of focusing on a point target.’

Photo credit: U.S. Air Force