Well Colt
Canada
spent some time with my unit doing "trials" before I departed the Army, and while I wasn't part of the trial, I did drop in to look things over and ask some informed questions.
The CC (Diemaco) reps had a series of modular chassis made of aluminium with various pieces that could be moved around to test ergonomics, notable observations of this bit of trials.
The "rifle" was always configured as a "bullpup" with a "D" style drip and guard, like the AUG series. In fact, if you were to look at that Bushmaster M17 rifle, add a D grip. make it silver and shorten the length you would have an excellent visual of their Lego Gun test chassis.
Bushmaster M17S shown for reference
https://www.milsurps.com/images/impo.../2iay6mh-1.jpg
The magazine was much shorter and thicker than the STANAG 5.56mm 30 rounder we know today. The CC Reps, when asked, indicated they are working on some "new" caliber options, no other explanations. If I had to describe it, imagine a magazine that could be a quad-stack of .30 carbine. The same footprint of two extended
M1
Carbine 15 round magazines taped together side by side.
The current issue Elcan C79 optic was in use for the trials.
A dummy M203 launcher was also mounted on some, but it was above the bore and the C79 mounted on top of that. The launcher did not work, so no idea how they planned to load or trigger it in that arrangement. Vertical parallax must have been silly as well.
Front pistol grips were mounted, as was some other high-speed junk, no provision or consideration for a bayonet was observed.
At this time, I consider all of the above to be masturbatory vaporware, the CC people didn't seem to be asking the troops what they wanted, they were presenting a school of thought and watching soldiers climb around and pretend to point it at things while squeezing dummy triggers.
From a reality standpoint, the Small Caliber Bullpup Lego Gun worries me, but the C7A2 service life upgrade is only 11 years old at this point, so I think we will not see any new replacement for some time. That, and the defense budget by GDP is the same as Spain and slightly less than
Japan
.