 An ambitious design for its era, the Mauler ran into intractable problems during development, and was eventually canceled in November 1965.Mauler's cancellation left the US Army with no modern anti-aircraft weapon, and they rushed development of the much simpler MIM-72 Chaparral and M163 Tracked Vulcan to fill this niche.These weapons were much less capable than Mauler, and were intended solely as a stop-gap solution until more capable vehicles were developed.