Having to eject from your aircraft pretty much invariably means you’re having a bad day, but that day could be much worse if you find yourself stuck behind enemy lines without the means to defend yourself. That’s the problem the Air Force is seeking to solve with the GAU-5A–a modified M4 Carbine assault rifle that breaks apart into two pieces for easy stowing in the ejection seats of modern combat jets.
The Air Force Gunsmith Shop, a group dedicated to the branch’s firearm repair and maintenance, were tasked with developing a weapon system that could engage targets accurately at up to 200 meters and fit into the storage compartment of modern ejection seats. Simple as that may seem, the challenges were plentiful: The service’s new M17 pistol would stow easily in the seat, but would be all but useless at 200 meters for anyone but the best of shots. The M-4 Carbine, another service favorite, could engage targets at that distance with plenty of room to spare… but at 33 inches long, the 7-pound rifle wouldn’t fit in the seat.
“The most rewarding part of my job is getting [small arms] through the shop and taking a weapon that has been beat up and heavily used, and returning it to the user practically brand new,” Richard Shelton, chief of the Gunsmith Shop, said in a press release.
“The other rewarding thing is when we work with the using community to develop specific weapons for a specific Air Force need.”
The solution, the Air Force Gunsmith Shop decided, was to create a break-down version of the M4 that could stow inside the seat and the GAU-5A was born.
The rifle, which is functionally the same as the platform employed by the Army, Marine Corps, and Air Force Security Forces, splits into two parts at the end of the receiver, allowing for the barrel to be removed and stowed alongside the weapon’s main body. As a result, the entire rifle and four fully loaded 30-round magazines now fit in the decidedly tiny dimensions of just 16 inches by 14 inches by 3.5 inches – the space allowed for storage in the standard ACES II ejection seat.
When fully assembled, the GAU-5A is shorter than a standard M4, thanks to its 12.5 inch barrel (cut down from the standard 14.5 inches). While the traditional M4 does split into two pieces (the upper and lower receivers), neither of these pieces would fit in the ejection seat storage space, so the Air Force opted for an off-the-shelf solution in the form of Cry Havoc Tactical’s Quick Release Barrel Kit (QRB Kit). The kit allows the shortened barrel and hand guard to be removed from the body of the rifle. Other modifications include front and rear sights that fold down, to further conserve space.
It’s not just important that the weapon fit in a compact space, it also has to come together quickly and easily. Ejecting from an aircraft is a rough ride, and any pilot in need of the GAU-5A Rifle will undoubtedly be experiencing a great deal of stress. Thats why it’s essential for the weapon system to go together and set up for use quickly and easily.
In order to utilize the GAU-5A, a pilot will just need to remove it from the back of the ejection seat, fold the pistol grip forward, insert the barrel, and pop up the sights. From there, it runs just like any other M4–just insert a magazine, rack the charging handle to the rear, and start flinging lead downrange. According to the Air Force, it only takes about 30 seconds to get the weapon into firing order.
Bail out weapons aren’t a new thing for the U.S. Air Force, and they’re not only seen as a means of defense. In the event a pilot is downed in rural territory, he or she may go days before they’re found. It’s not unheard of for pilots to see their bail out weapon as much as a hunting platform as a defensive weapon. Of course, previous bail out weapons were chambered in .38 or even .22 calibers, which made small game hunting more realistic. The GAU-5A delivers far more firepower, which makes it a more effective defensive weapon than rabbit-hunting tool.
A total of 7.200 of the GAU-5A platform have gone out to Air Force units around the globe, according to Popular Mechanics.