Editing GAU-12 Equalizer (section)

==Development==
The five-barrel Equalizer cannon was developed in the late 1970s, based on the mechanism of the 30mm [[GAU-8/A Avenger]] cannon, but firing a new [[NATO]] series of 25&nbsp;mm ammunition. The GAU-12/U cannon is operated by an 11&nbsp;kW (15&nbsp;hp) [[electric motor]], or in external mounts supplied by a [[bleed air]] driven pneumatic system. Its rate of fire is normally 3,600 rounds per minute, with a maximum of 4,200 rounds per minute. For use in the [[AC-130]] gunship, the fire rate is limited to 1,800 rounds per minute in order to conserve ammunition and reduce barrel wear.

===GAU-22/A===
The '''GAU-22/A''' is a four-barrel version of the GAU-12/U designed for use on the [[F-35 Lightning II]].<ref>{{cite web |title=25mm Gun Systems for the F-35 Joint Strike Fighter |url=http://www.dtic.mil/ndia/2006garm/thursday/maher.pdf |publisher=[[National Defense Industrial Association]] |last=Maher |first=Dave |date=2006-03-30 |access-date=2008-10-14 |url-status=dead |archive-url=https://web.archive.org/web/20071029160922/http://www.dtic.mil/ndia/2006garm/thursday/maher.pdf |archive-date=2007-10-29 }}</ref>   
The GAU-22/A's major difference is the use of four barrels, rather than the GAU-12/U's five barrels.  The GAU-22/A is lighter and has a reduced rate of fire of 3,300 rounds per minute, but maintains the same, high accuracy of 5 [[milliradian]]s, 80% circle<ref>[https://www.gd-ots.com/armaments/aircraft-guns-gun-systems/gau22a/ GAU-22/A fact sheet] General Dynamics</ref> of the GAU-12<ref>[https://www.gd-ots.com/armaments/aircraft-guns-gun-systems/gau12u/ GAU-12/U fact sheet] General Dynamics</ref> and A-10's GAU-8.<ref>[https://www.gd-ots.com/armaments/aircraft-guns-gun-systems/gau8a/ GAU-8/A fact sheet] General Dynamics</ref> The weapon is produced by [[General Dynamics]] Ordnance and Tactical Systems.

The [[Nammo]] 25&nbsp;mm PGU-47/U [[High Explosive Incendiary/Armor Piercing Ammunition|APEX]] (Armor Piercing with Explosive)<ref>{{cite web |url=https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2014/armaments/Wed15439Sande.pdf |title=APEX – Armor Piercing with Explosive. The Dual Purpose Round for the F-35 |website=[[Nammo]]}}</ref> projectile has been developed for the GAU-22/A.<ref>[http://www.upi.com/Business_News/Security-Industry/2010/11/29/Norway-contracts-for-F-35-ammunition/UPI-87971291045636/ "Norway contracts for F-35 ammunition."] ''UPI'', 29 November 2010.</ref>
It features a tungsten carbide penetrator in the tip and an explosive fragmentation body, to be multi-purpose against both hardened and soft targets. Also, the presence of a [[Ratchet (device)|clockworking]] inertia-driven mechanical [[fuze]] in the mid-body, protects the round from shocks, misfires and cookoffs, making it safer to handle and fire.