The Aggravated Particle Cannon, or APC for short was the precursor to the modern day MAC Gun. It was capable, at full power, to decimate opposing capital ships in 3-4 shots. Though, when attempted to be outfitted to ships in the UFS fleet it was limited in success in use. So the UFS commissioned Aero Industries to produce a new design for a gun that could be outfitted to HIR defenses as well as ships in its fleet. Upon the completion of the first MAC gun the APC gun was quickly replaced and retired. Most of the devices were destroyed or simply decommissioned and secured in a stockpile in central space.