I have tried to piece together the Greek M163 equivalent best I can, this is what I have so far.
Two tests of the M61A1 Vulcan on the M113A1 hull were conducted on March 30th, 2012, and 11th of January 2014. This is referenced by the official Hellenic army website itself.
Activities – Army.gr
I think this might be the first prototype after a few changes? The serial number is unfortunately censored but the camo scheme is identical. Regardless, the lack of a refined gun mount and sighting device is obvious to set it aside from the newer model.
Spoiler
Initial vehicle featured in this suggestion, likely quite early in development judging by the rudimentary and oddly colored gun mount, the BMP-1/ZU-23 combination to the left (see full image in suggestion) is a pre-production testing vehicle for the ones we know today. The M113A1/ZU-23 combination to the right is also a prototype, so this was probably back before the army had decided which weapon they wanted to arm this APC with.
Images of the same APC, identified through the camouflage, lower plate number (on the first image you can just barely see that it’s a 12 or 13), and the almost identical albeit repainted gun aparatus with the large yellow X. Alongside the Sokous vehicle at the bottom of this suggestion, these images are quite possibly from one of the two reported tests of this vehicle.
![image](https://forum-en-cdn.warthunder.com/original/3X/e/1/e1066e3f12e72e20153815580bde4f05a5d2ffca.jpeg)
![image](https://forum-en-cdn.warthunder.com/original/3X/7/1/71a9e7709d9e3976c674dc45e7f5c88d255e41a9.jpeg)
Somewhat recently, on June 5th, 2024, a new model was revealed, with what appears to be a thermal sight, and reportedly, new internal computer systems (FCS?) developed after feedback from Ukraine.
Spoiler
![image](https://forum-en-cdn.warthunder.com/original/3X/3/2/32dde6850b729d84812cfbd1c1fad0f834f9a764.jpeg)
There are a few slight variants I could find of this last photo, which tells me that there may possibly be a video somewhere.
It seems there is a completely separate vehicle developed by Greek company Sokous Robots. I am not sure how it connects to the other prototype featured in this suggestion; perhaps it was merely an independent competitor. Nonetheless, the technology included is certainly more sophisticated over the other prototype from this time period.
Spoiler
The first of two videos, a simple firing test, was taken 12 years ago, which confirms that this vehicle is from the initial developments of this project. The second video is a more in-depth view of this prototype.
The embed for the first video wasn’t working, so you can paste DefenceNet.gr - Βολή M113 Gatling into Youtube to find it instead. Alternatively, I have a slightly shortened version I downloaded from Twitter.
Second video below
https://youtu.be/hLj9nHsKmHY?si=DFOnE1wpoI6XfTDU
Two images of this prototype. Interestingly, I happened to find the first one on the same official Hellenic army website that I did for the testing photos of the other early prototype, so the Sokous vehicle was either tested alongside the it or closely monitored by the military enough so that its imagery would appear in the same photo group (on purpose or by accident). Note that the first image also has a timestamp for March 30th, 2012, which further reinforces this date as the testing period for this prototype.
![image](https://forum-en-cdn.warthunder.com/original/3X/c/a/ca32ba6115124e74f4934bc10b5b4e56a13e3814.jpeg)
![image](https://forum-en-cdn.warthunder.com/original/3X/4/9/49e0885774c2567700944ba263a2114831ccb249.jpeg)
Anyhow, that’s what I’ve gathered for the moment, but evidently the Hellenic knockoff M163 is a lot more than some makeshift unit modification. And as of this year, it seems that Greece has reignited this project, so I am interested to see where it eventually leads.