Watch This: F-35B Fires GAU-22 External Gun Pod in Flight

New Caliber Gun Provides Close Air Support Capability for U.S. Marines.

The U.S. Marine Corps Lockheed Martin F-35B Lightning II Joint Strike Fighter has completed the test firing of its externally mounted General Dynamics GAU-22 25mm gun pod.

The final aerial test firing took place on May 8, 2017 and was conducted by The Salty Dogs of Air Test and Evaluation Squadron (VX) 23’s Integrated Test Force (ITF) at Naval Air Station (NAS) Patuxent River.

Of particular interest in the video just released (that includes footage from several different sorties) is the variety of additional external stores carried on the test F-35Bs. The aircraft are shown with a version of the AIM-9X Sidewinder air-to-air missile and, in a separate flight, with what appears to be a 500lb laser guided bomb possibly a version of the GBU-12 Paveway II.

The new General Dynamics GAU-22 25mm gun pod uses a unique four-barrel configuration that was developed from the highly successful five-barrel, 25mm GAU-12/U gun also built by General Dynamics. The new GAU-22 gun, carried internally on the USAF F-35A variant and in the external pod for the U.S. Marines’ F-35B is and U.S. Navy F-35C is more than 40 pounds lighter and requires 20 percent less overall space than the earlier GAU-12, 5-barrel 25mm gun. The new GAU-22 weapon has a reported rate of fire of “up to 3,300 rounds per minute”. The rate of fire of aerial guns is often reported as “up to…” since the gun can take several seconds to achieve its maximum rate of fire because of the weight of the rotating gun barrels.

The GAU-22A Gun Pod. (Image credit: LM)

The successful in-flight test firing of the 25mm gun pod (started at the end of February), specifically on the U.S. Marine Corps F-35B, somehow addresses questions over the F-35 program’s ability to perform the close air support mission. Several analysts have expressed concern over whether the F-35 is suited for the close air support mission and is a suitable substitute for the CAS-specific A-10 Warthog.

Generally speaking it’s wrong to compare the F-35 with any other asset that was designed to perform a specific mission: the A-10 was built around a unique 30mm cannon nearly as long as the aircraft’s entire fuselage that was intended for the anti-armor close air support (CAS) mission.

While this initial test-firing does not resolve questions surrounding all of the F-35B’s close air support capabilities it is another successful step forward in the program’s progress. At least it can use the gun if called into action during a CAS mission!

The F-35 GAU-22/A gun has been among the most controversial topics: some criticised the fact that the Joint Strike Fighter’s gun can only hold 181 20mm rounds, fewer than the A-10 Thunderbolt’s GAU-8/A Avenger, that can hold some 1,174 30mm rounds.

Moreover, although it was designed with LO (Low Observabity) characteristics, the external pod degrades the F-35’s radar cross section making the 5th generation aircraft more visibile to radars. Still, this should be acceptable for the scenarios where the U.S. Marine Corps F-35B will be called to carry out CAS missions.










About Tom Demerly
Tom Demerly is a feature writer, journalist, photographer and editorialist who has written articles that are published around the world on,, Outside magazine, Business Insider, We Are The Mighty, The Dearborn Press & Guide, National Interest, Russia’s government media outlet Sputnik, and many other publications. Demerly studied journalism at Henry Ford College in Dearborn, Michigan. Tom Demerly served in an intelligence gathering unit as a member of the U.S. Army and Michigan National Guard. His military experience includes being Honor Graduate from the U.S. Army Infantry School at Ft. Benning, Georgia (Cycle C-6-1) and as a Scout Observer in a reconnaissance unit, Company “F”, 425th INF (RANGER/AIRBORNE), Long Range Surveillance Unit (LRSU). Demerly is an experienced parachutist, holds advanced SCUBA certifications, has climbed the highest mountains on three continents and visited all seven continents and has flown several types of light aircraft.


  1. The limited amount of ammo carried versus the huge monies invested should be a non starter to any thinking person. However we are not talkingn about a rational thinking person, but a political football that both military complex and politicians are drooling over.

    • Please be sure there are very, very rational thinking people behind this project. You just have to look at F-35 from another angle. This is absolutely brilliant project, aimed for making money. Lockheed Martin earns tons of bucks of F-35, employ thousands of people and shows excellent financial results year by year. The only thing they have to do is to continue development of F-35, the longer the better. They are simply not interested in finishing this project.
      So this is just a matter of priorities: you expect to receive capable combat aircraft, LM expect good financial reports in years to come.

      • “The only thing they have to do is to continue development of F-35, the longer the better. They are simply not interested in finishing this project.”

        > oh you mean like Sukhoi’s PAKFA project? How many aircraft do they have? 9? After 7 years of advertising, rhetoric, and propaganda all they have to show for are 9 aircraft and one with a new paint job. *slow clap, slow clap*

        • You confused PAK FA with F-35. May I remind you that first flight of what later became F-35 happened back in 2000, 17 years back. First pre-production F-35 was delivered in 2010. All we have after 17 years of advertising, rhetoric and propaganda are 200 of airframes with endless iterations of structural modifications and software versions. Out of these 200 airframes only 12 declared IOC.
          The very first PAK FA took off in 2010, and after 7 years of development they have 8 test machines participating in various tests and an airframe, T-50-9, which is (almost) identical to the version which will go to full scale production.
          Much more mature approach, I would say. And much more cost effective.

          • Let’s do some corrections because your assumptions are WRONG.

            “I remind you that first flight of what later became F-35 happened back in 2000, First pre-production F-35 was delivered in 2010”

            > though you are correct that the x-35 flew in 2000. That was for the dem/eval between the lockheed Martin design and Boeing’s x-32. Though this is not the start of the JSF Program, this is where it really started to come to light. The X aircraft that flew having little to nothing in common with current the aircraft. The first preproduction F-35A was introduced in 2006, F-35B in 2008, and F-35C in 2010.

            “All we have after 17 years of advertising, rhetoric and propaganda are 200 of airframes”

            > that is still 191 MORE airframe then the PAKFA. Though currently that number is 231 so really that is 222 MORE aircraft aircraft than the PAKFA. So if we’re going to use simple math that would mean on average there are 21 F-35s produced per year compared to 1.28 PAKFAs produced per year.

            “with endless iterations of structural modifications and software versions”

            > Most of not all structural modifications are either approved, in the process of being applied, or completed. Only the F-35C is left in concerns with its landing gear. The aircraft has the highest use of software for any current aircraft. Most any future update/upgrade to the aircraft will depend heavily on the software code. Even the F-22 is still having software updates/upgrades. So what is your point?

            “Out of these 200 airframes only 12 declared IOC.”

            > The USMC currently has two squadrons of F-35B and the USAF currently has one. So that would mean the number of total aircraft in IOC is closer to 36. That is 36 more aircraft than the PAKFA currently have zero ( none, nikto, zilch, nada). Of course the current 231 that encompasses all variants of the F-35 and users.

            “The very first PAK FA took off in 2010, and after 7 years of development”

            > Even though F-35 development is still going on and there are actual production or service model that have been delivered. Sukhoi has delivered 0 (ZERO) production versions of the PAKFA meant for service or for training. No current version of the PAKFA have completed major components like the engine or radar.

            “8 test machines participating in various tests and an airframe, T-50-9, which is (almost) identical to the version which will go to full scale production”

            > yes… They are all test machines you have that right. Almost? What about the engines, avionics, radar and weapons? The only test I’ve seen concerning weapons was on a PAKFA mock up using its cannon.

            “Much more mature approach, I would say. And much more cost effective.”

            > well that is just your opinion and doesn’t reflect that facts of reality.

            Here is a lockheed martin advertisement called “by the numbers”.


  2. Only the F-35A has an internal gun. Only has 180 25mm rounds……just enough for maybe 3 second squeeze on the trigger.

  3. I am still waiting for my brass from these shoots. Weather was nice and was a good distraction from normal to go out to there and hand crank ammo in. This has just enough ammo for one good gun run, not going to help much in CAS. A-10 fires 100-300 rounds, depending on requirements of the fight, of much larger 30mm HEI rounds. However the 20mm rounds are next to useless, so at least the few bullets it does have are halfway descent.

    • 1 250lbs guided HE multifunction (airburst, impact, and penetrating) guided munition that can be accurate within 1 meter, is more effective then 100 rounds of 30mm HEI rounds. The 25mm for the F-35 that will most likely be computer controlled is said to be more accurate then the former and fires armor piercing explosive rounds. A 25 or 50 round burst would give any soft or lightly armored target a bad day. In either case I wouldn’t want to be on the receiving end of either of them.

      • Well the 250lbs SDB is a good weapon, especially the newest versions. But, sometimes area of effect is key cause even the guy on the ground doesn’t know where the bad guys are. So you have to saturate the area with powerful weapons. Also, the “frag zone” of a SDB is still greater than a 30mm HEI run. Also, and I know this from being in the CAS community for more than 14 years, sometimes GPS grids just can’t be established and the guys in the ground need weapons NOW, and “That treeline over there” Is their targeting. So we will always need gun. I have worked on, loaded both systems, the GAU-22 is a baby compared to the GAU-8 monster.

  4. The AV-8B Harrier is the primary fixed wing CAS aircraft for the USMC and it uses a 25mm gun pod and doesnt have that many rounds over the GAU-22A of the F-35. I dont hear people complaining about the Harrier or the FACT that all variants of the F-35 carries more bullets then any European or Russian fighter aircraft.

  5. “… low-collateral bombs…”
    Thats not what Ive read. The implication of your post is that dropping bombs is always preferable, reality shows clearly thats not the case.

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