top of page
Search
  • Writer's pictureMAC

Why the GAU-5A uses a detachable barrel

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?"

People have been asking this question since the advent of QD barrel assemblies for AR15's. 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 AR15's significantly reduce the over all 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 28-1/2" in overall length. That's pretty short by conventional rifle standards (again, this is a pistol with a brace vs. a stock). However, the Air Force 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, 28-1/2" 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.

We are at about 21-1/2" if it were to be stored this way. Clearly this isn't going to fit into the ACESII bag shown in the preceding image. Now lets take a look at the GAU-5A disassembled for storage under the pilots seat and see how long it is.

Now the entire package is just over 15" which allows it to store neatly in the ACESII ejection seat survival kit. There is over a 6" difference between removing the barrel from the upper receiver vs. unpinning the upper and lower. Hopefully this illustrates why the Air Force wanted to QD barrel on the new GAU-5A and answers any questions you may have regarding the purpose and/or utility of QD barrel systems.


10,411 views5 comments

Recent Posts

See All

5 comentarios


Edward Van Natta
Edward Van Natta
06 may 2020

I am looking for about your product please leave me a message. When I post this, I am looking for more information on this. I am looking for more information where I can find this at and how much do they run I want to get one for a small purse spring or her a boat.

Me gusta

The ACESII kit is 16x14x3.5 inches. That means the diagonal is 21.25 inches which would probably fit the intact upper with a little wiggling. It even looks like the quick attach barrel system adds about an inch to the gun so with that gone it would almost certainly fit.


Im also wondering if a bullpup would work as well. The Tavor X95 330 has a 13 inch barrel and an OAL of 22.8 inches. The USAF could probably get a special run with a slightly shorter barrel that would fit diagonally.

Me gusta

Tim Harmsen
Tim Harmsen
21 abr 2020

I don't think the purpose of this weapon is to hunt as food is supplied in their survival kit. What they're attempting to do is evade capture until PJ's can come for them. They aren't prepared to live in the wilderness for months on end, camping, fishing, hunting, etc. I think a 300BLK with a silencer option would be interesting along with 3 mags of supersonics and 1 mag of subsonics. However silencing a 5.56 with a 14" barrel is an exercise in futility.

Me gusta

I understand why this system for the Air Force is important and niche to the demands of space on aircraft ejection seats. However, there are other platforms out there that are just as effective in fire power that are smaller and less prone to losing zero or having to be assembled before being able to be used. These guys are in an escape, avoid, evade mode when on the ground. I would think an easily silenced caliber would be of more benefit for hunting or protection. Let’s face it, the downed pilots aren’t looking for a fire fight at 100-200 yards against a superior enemy force.

Me gusta

jscott.sherrill
jscott.sherrill
21 abr 2020

This is a good explanation - and it has been out there for sometime while they were developing this firearm. In your IG post, the questions were insane -- meaning most people dont know exactly why the Air Force made this thing. Also, there has been some discussion of durability of different parts. Keep in mind that this thing is not meant to be used day in and day out. If it ever does get used, it will be HOPEFULLY for a very short period of time. And with only 120 rounds, it wont have to survive any kind of torture test in actual use. A pilot who is shot down -- the main goal is for them …

Me gusta
bottom of page