How the GAU-8A Avenger works

[Sr.]

 

[Diesel_Thunder]

Nice video, thanks for posting that!

 

Does make me wonder though, what does the bypass chute do? It's not a feature on its smaller cousin, the Vulcan 20mm.

[silverdevil]

the GAU-8 returns the spent casings to the to the ammunition drum. the ammunition weighs 3400 pounds before firing. returning the casings assists with balance of the aircraft. some M61 have dual ended feed and do return casing to drum. during testing it was noted that spent casings and links could get sucked into engine. that would be bad.

[Zimmerdylan]

Pretty friggin amazing

[ZeroReady]

Now I'm not an expert, but I have heard that the actual links between the rounds are paper/carboard. I do have plenty of trigger time behind SAWs and 240Bs though, and I know those metal links weigh something. I just think it's amazing the GAU8 does what it does how it does.

[Frederf]

Sources say the ammunition is linkless. Any connecting devices I think are only for loading purposes. Crazy that the M61 had linked ammo that was eliminated for the M61A1 version.

[Diesel_Thunder]

I’ve never loaded a GUA-8, but have loaded the M-61 (CIWS). The ammunition is shipped with it linked with steel links. The loader delinks the rounds and feeds them into the drum, while the links feed out of a seperate chute still linked together. If I recall, we saved the links as we could reuse them to unload the drum and not deal with loose rounds. 

[Frederf]

The airplane mounts like in F-16 don't have linked ammo. I guess the ground-based stuff does.

[panton41]

On 5/7/2021 at 2:42 PM, Diesel_Thunder said:

I’ve never loaded a GUA-8, but have loaded the M-61 (CIWS). The ammunition is shipped with it linked with steel links. The loader delinks the rounds and feeds them into the drum, while the links feed out of a seperate chute still linked together. If I recall, we saved the links as we could reuse them to unload the drum and not deal with loose rounds. 

That's interesting, because I've always assumed the cartridge was part of a link's structural integrity.

 

Then again, I can't say I've ever handled linked ammunition before.

[Diesel_Thunder]

On 5/7/2021 at 6:26 PM, Frederf said:

The airplane mounts like in F-16 don't have linked ammo. I guess the ground-based stuff does.

 

No, even the ground and shipboard M61's use linkless ammunition.

 

On 5/9/2021 at 9:22 PM, panton41 said:

That's interesting, because I've always assumed the cartridge was part of a link's structural integrity.

 

Then again, I can't say I've ever handled linked ammunition before.

 

Having it linked in the box really helps in the loading process. I can't recall how many 20mm rounds come in a box, I think it's 200 or 250 (it's been a few years ), but each link has a hook on one side and a loop on the other. A full load on a CIWS drum is 1,550, so you'd need 8 boxes to (assuming 200 rds/box) to give it a full load. As one box is loaded, you can attach the links from the tail end of one box to the beginning of the next box to keep the process going. You also have to have empty boxes nearby to catch what is coming out of the drum (usually the dummy rounds).

 

With the loader machine attached, the loader will strip the links off of the rounds as it passes though. Loose live rounds (or dummy rounds) are then fed into the drum. The links are then attached to fired cases coming out of the drum, dummy rounds that may have been in the drum, or remain empty if there was nothing in the drum. You usually will want gloves on as the steel links are pretty tough, and have edges that can catch your skin if you aren't paying attention.

 

We normally kept dummy rounds loaded if live ones were not loaded as they add weight to counterbalance the radomes mounted above it.

 

Here's a video showing the loading process, the yellow gadget is the loader. Live 20mm are going in, and you can see the dummy rounds coming out:

 

https://www.af.mil/News/Radio/videoid/725262/dvpTag/integration/?videoid=725262#.YJveJASKKSg.link

Edited May 12, 2021 by Diesel_Thunder

[DmitriKozlowsky]

On 4/12/2021 at 7:07 AM, silverdevil said:

the GAU-8 returns the spent casings to the to the ammunition drum. the ammunition weighs 3400 pounds before firing. returning the casings assists with balance of the aircraft. some M61 have dual ended feed and do return casing to drum. during testing it was noted that spent casings and links could get sucked into engine. that would be bad.

Gen1 M61 installations on F-104 , during testing & trials, had a nasty habit of severe blowback and misfires, resulting in FOD damage to the engine. 

[Donglr]

Until I saw this my assumption was much simpler: it goes "Brrrrrrrt!" and something goes pop!