"In 2007, AFSOC initiated a program to upgrade the armament of existing AC-130s still in service. The test program planned for the 25 mm GAU-12/U and 40 mm Bofors cannon on the AC-130U gunships to be replaced with two 30 mm Mk 44 Bushmaster II cannons. In 2007, the Air Force modified four AC-130U gunships as test platforms for the Bushmasters. However, AFSOC canceled its plans to install the new cannons on its fleet of AC-130Us. It has since removed the guns and re-installed the original 40 mm cannons and returned the planes to combat duties. Brig. Gen. Bradley A. Heithold, AFSOC's director of plans, programs, requirements and assessments, said on 11 August 2008 that the effort was canceled due to problems with the Bushmaster's accuracy "at the altitude we were employing it" in tests. There were also schedule considerations that drove the decision, he said."