the historical reference in question:
I love how westerners need to keep rediscovering the "simpler equipment that you can actually make a bunch of beats the amazing wunderwaffe" idea over and over again, you'd think WW2, you know, literally the largest war ever fought, would teach some lessons, but I guess not
Apparently that's just the name of the company, which rather than having anything to do with biological research, is actually "the swimming pool and spa water care division of Lawrenceville, Georgia-based KIK Consumer Products" (which I guess explains the chlorine).
Now, why the hell would you name your swimming pool sanitation company "BioLab" is beyond me, like genuinely who thought that one up.
For the revolvers in general, it has to do with reliability and usage of specific ammunition to avoid overpenetration. While today we generally consider self-loading pistols to be sufficiently reliable, this wasn't necessarily the case in the 60s and 70s, especially with the aforementioned types of ammo. Additionally, pistols with large-capacity magazines were just starting to become a thing, so a 6-shot revolver didn't actually have that much less ammo compared to most other pistols of the time.
For the scoped version specifically, it had to do with sniping in urban conditions, where you don't necessarily need a very long effective range, but you do want your weapon to not have a long rifle barrel sticking out of a window, giving away your position.
Here's a video by Forgotten Weapons that goes into more detail: https://www.youtube.com/watch?v=P1zEUGck8NE
Silent Storm (and its expansion Sentinels, they're sold together as Silent Storm Gold Edition), an XCOM-style game set in WW2 (with some sci-fi elements, like dieselpunk mechs that show up later on), featuring awesome environmental destruction mechanics. It's got a lot of jank, but it's still really cool.
opening up a 3rd front in order to open up my 2nd front, in order to, uh... what was I doing again 
Nope - the Colt LMG has neither water cooling nor a quick-change barrel mechanism. There was an earlier prototype which featured the barrel change part, but that didn't make it to the final iteration
France sent a bunch to Russia during WW1 (I'm not sure if they were military aid à la WW2's Lend-Lease, or were actually bought by the Russian government), and they were later inherited by the Soviets after the civil war.
Just a handguard, it doesn't really serve any mechanical purpose, just covers the barrel & gas tube. I'm not sure why they went with this design as opposed to a more typical M16 handguard (as was actually the case in earlier attempts to make an M16-based LMG)
On the Colt IAR, which is a further evolution of this concept, there's also a big chunky handguard, but there it actually goes over a heat-sink around to barrel (you can see a bit of it poking out after the end of the handguard in this picture)
The LMG doesn't have anything like that, so yeah, I don't know why they went with that design.
apparently
While belt-fed machine guns and even their semi-auto counterparts are banned in the UK, this ammunition feeding system itself is not
this rifle is merely a manual repeater
Here in the UK, we can’t have semi-auto firearms BUT – we can load our guns with as much ammo as we can (no magazine restrictions!)
https://xcancel.com/ArmchairW/status/1839453350854853047
There's actually a critical lesson to draw from this and other Ukrainian fiascos, of which the Bakhmut saga and the Zaporozhie Hundred Days come to mind: Ukraine will have ended up losing this war in large part because it consistently tried to fight beyond its means.
The Ukrainians started this war with an enormous army, well in excess of what the Russians could and actually did commit to the fight in 2022. That huge force (the "First Army") was badly mauled in early 2022, but it was rejuvenated later that year by a combination of ruthless mobilization and massive aid from NATO. This convinced the Russian Stavka to transition to the defensive and consolidate their position in Ukraine, withdrawing troops from more exposed positions in east Kharkov and right-bank Kherson. Any serious assessment of the situation at that point would have been that the Russians had consolidated into a basically impregnable position that the AFU was incapable of breaching (lest we forget in the wake of Russia's totally unhindered withdrawal from the area, their attempts at reducing the Kherson bridgehead by force in mid-2022 were bloody disasters), and the correct course of action was to start digging in and negotiate a peace treaty in the meantime.
The Ukrainian leadership instead threw a disturbingly large portion of the "Second Army" into Prigozhin's meatgrinder in Bakhmut and then ordered not one but two large-scale counteroffensives into Zaporozhie and the Bakhmut flanks using the post-Bakhmut remains of the "Second Army" and their NATO-supplied "Third Army." Those failed with enormous losses, opening the way for Russia to transition back to the offensive in late 2023 and begin systematically rolling Ukraine out of the Donbass. The correct course of action at this point was, again, to find a tenable defensive line and start digging. Zelensky instead ordered a "Hail Mary" offensive in Kursk with the remnants of the "Third Army" and significant elements from a lightly-equipped "Fourth Army," hoping Russian border defenses were weak despite their having ample warning of Ukrainian designs on the border region (courtesy of several earlier, smaller raids) and plenty of time to prepare. It proceeded to fail with enormous losses - Ukrainian forces breached the border, began to exploit, and ran square into a Russian haymaker counter-punch that stopped them in their tracks. The Ukrainians then reinforced failure, sending massive reinforcements into a death pit in an attempt to keep a sliver of Russian soil under their flag as a middle finger to Putin.
And while this was happening the front in the Donbass started to collapse with Russian troops making large advances and seizing key terrain, in no small part because the AFU's resources had been systematically redirected to a tertiary operation far to the north. We've seen, again and again and again, that when the Ukrainians got resources and generated forces, rather than admitting they are the weaker power here and working to strengthen their positions and conciliate, they instead squandered them on hugely ambitious and equally doomed offensives. In 2023 these offensives were aimed at restoring their pre-2014 borders when Donetsk may as well have been on the Moon for them, while in 2024 their ambitions transitioned to the outright insanity of conquering southwest Russia despite the fact they'd been on the military back foot for the last year. These are the moves of a power setting objectives beyond its means to achieve, and they will probably end up dooming Ukraine as a sovereign state going forward.
HK did actually develop a prototype along those lines (I think it was using proprietary magazines though, not sure), but it didn't end up going anywhere
however, there are actually modern license-built rifles that implement the concept (this one without a stock for US law reasons)
https://xcancel.com/maphumanintent/status/1720933055307600231
Fun theoretical exercise I'm currently working on for the @fortisanalysis side of things:
US refineries (total) only store about 40 million gallons of military-grade jet fuel at any given time, or about 36,400 flight hours for an F/A-18E/F Super Hornet launched from an aircraft carrier. For 40 x -18's per carrier, this is about 910 flight hours. A carrier holds roughly 3 million gallons of fuel for its wing, about 68 flight hours per bird. Now consider that a notional mixed complement of 20 x F-35's and 20 X F-15EX's operating out of Kadena AFB would consume about 62,400 gallons per hour combined. Thus, just a single carrier wing and a single AFB wing's complement of fighters (80 combined) theoretically all operating at once would drink 106,400 gal/hr.
So...
The net stores of military jet fuel immediately available from US refiners above the global contingency supplies managed by the Defense Logistics Agency at any time represents about 375 net flight hours for one carrier and one air wing...less than 16 days of high intensity air operations by far fewer assets than the US would throw into an all-out theater conflict in the Pacific Rim. DLA Energy ended FY2022 with 1.68 billion gallons of on hand inventory of jet fuel to serve the entire DOD combined inventory of 14,000+ aviation assets - cargo, fighter, rotary wing, bombers, drones, tankers, and recon. Which begs the question: How fast would two theaters of conflict burn through all contingency supplies of fuel? And what does DOD do when the well runs dry?
Reminder that for the Gulf War's air campaign, the US had nearly 6 months to prepare, move assets into place, build up whole new infrastructure, etc., right next to Iraq without the Iraqis being able to do much to respond. Westerners love to call back on that campaign to justify their belief that the US/NATO could totally destroy any opponent in just a few weeks with their superior air forces, but completely ignore the logistical realities of actually doing so. And today, with the proliferation of long-range precision munitions, actually managing to build up the concentrations of forces and supplies necessary for large campaigns like this is substantially more difficult - we see this already in Ukraine, with Russian deep strikes doing significant damage, taking out ammunition depots and arms shipments, and wiping out various gatherings of Ukrainian troops and mercenaries.
If Iraq had the ballistic missiles that Yemen wields today, things could have gone very differently back then.
Bingo! Rockdale County chemical fire: Biolab has a history of fires at facility