ATK [ATK] said a modified variant of its Mk44 Bushmaster Automatic Cannon medium-caliber weapon was recently type classified as the GAU-23 by the Air Force for integration on AC-130W gunships.

The GAU-23 Bushmaster Automatic Cannon uses the 30x173mm PGU-13, PGU-15, and PGU-46 ammunition. ATK spokesman Rod Gibbons said the PGU-13 is a high explosive incendiary round used on light material targets. PGU-15 is a low-cost, target practice round ballistically matched to the PGU-13. PGU-46 is a modification of the PGU-13, adding a low drag fuze for performance at extended ranges.

In addition to the AC-130W, the GAU-23 is also used on Alenia Aermacchi’s MC-27J. The MC-27J is a multi-mission, armed, Roll-On/Roll-Off (RO/RO) derivative of the C-27J. Alenia Aermacchi is a division of Finmeccanica.

“Combined with our 30mm PGU-46/B ammunition, the GAU-23 cannon provides unequaled range and accuracy for integration on airborne platforms for any number of allied countries,” ATK Defense President Mike Kahn said in a statement. “This is just one example of our affordable and innovative technologies and services that provide enhanced solutions and capabilities to our customers worldwide.”

In February, ATK expanded its aviation weapons solution through the development of a RO/RO pallet and weapons mount that integrates with the GAU-23 cannon, it said in a statement. The resulting weapons package will allow medium-lift platforms the ability to install the system in less than four hours without airframe modification.

The Air Force in June 2011 announced the conversion of 12 of its Special Operations Command MC-130W Combat Spear aircraft to the Dragon Spear configuration. ATK also developed and produces the 30mm PGU-46/B High Explosive Incendiary (HEI) ammo used on this gun system.

Air Force Special Operations Command (AFSOC) spokeswoman Capt. Kristen Duncan said in an email yesterday that the prototyping effort for the GAU-23 took approximately 14 months from beginning to end. She said the average prototyping effort depends on the complexity of the system but “averages five-to-seven years.”