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US Air Force GAU-5A Rifle with Detachable Barrel

Why does the USAF GAU-5A rifle feature a quick detachable barrel system? It's all about available space in fighter aircraft.

US Air Force GAU-5A Rifle with Detachable Barrel
Did you know the US Air Force’s GAU-5A Survival Rifle features a quick detachable barrel system? Tim Harmsen explains why it’s a needed feature.

Since posting my recent video on the new Air Force GAU-5A rifle, I've had a number of questions by viewers asking me, "Why use a detachable barrel when you can unpin the upper from the lower and stow it that way?" If you are unfamiliar with newest US Air Force Survival Rifle you can read about it here in my friend’s, David Fortier, article.

People have been asking about the utility and practicality of a QD barrel assembly for AR15 since their adventgun Given detachable barreled rifles and pistols have been around for years, I have assumed this question would have slowly dissipated over time, but it hasn't. QD barrels on AR15s significantly reduce the overall length of the stored rifle/pistol when compared to rifles stored with the uppers unpinned from their lowers. Let's take a look at the GAU-5A a bit closer and take some measurements.

The assembled pistol above is about 28.5 inches in overall length. That's pretty short by conventional rifle standards (again, this is a pistol with a brace vs. a stock).

The Air Force, however, needed to fit a carbine into a very small pouch as part of the currently issued ACES II survival kit that stores under the ejection seat of fighter aircraft. In its configuration above, this clearly isn't going to work.

Here's a picture of the new GAU-5A in the ACESII pouch it's required to fit into if it's going to fit under the ejection seat.

Yup, 28.5 inches isn't going to cut it. That's why the Air Force had to get creative. But wait, what about the idea of simply unpinning the upper from the lower and storing it that way? Let's take a look at the overall length of the same gun with the uppers and lowers separated.

Simply removing the entire upper receiver from the lower does not shorten our pistol enough to meet the stringent length requirements of the US Air Force dictated by the available space.
By being able to remove the barrel-handguard assembly, the GAU-5A suddenly becomes drastically shorter allowing it to meet the overall length requirements. If needed, it can be quickly reassembled, without tools, in seconds.

Hopefully, this illustrates why the Air Force wanted a Quick Detach barrel on the new GAU-5A rifle and answers any questions you may have regarding the purpose and/or utility of QD barrel systems.

About the Author

Tim Harmsen is the founder of the popular Military Arms Channel on Youtube and you can follow his writing here.

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