There's C-mags that work fine, it's just that the chances of an unreliable one are known to be pretty high. They're not all bad, just enough to make them an iffy choice in large numbers.
I agree with F16 about the LMG/Automatic Rifle choice by the Marines. To me the role calls for a belt-fed, something with deep ammunition reserves that can keep calling down bursts with long gaps between reloading. Something accurate, as well, with tight groups that can be used on a point target as well; it's why I like the Ultimax 100. The constant-recoil system in that does a fine job of reducing kick since the bolt isn't impacting the receiver, and it stays on target better. That it's the weight of an assault rifle is just gravy; less gun weight means more ammo being carried.
Granted, one point in favor of the IAR is the weight, 9 pounds vs 22 pounds for the M249. That's probably being reinvested into ammunition, so the overall load doesn't change (fifteen pounds for 22 magazines) as far as weight goes. Another point of favor is that, with everyone being issued M27 IARs, anyone can operate in the squad automatic weapon role. So there's some good out of this, despite the downsides.
All right, I'll put in a third mortar tube in the weapons company. Including attachments, that brings my company to 203, which is pretty big compared to the Army's light infantry company. Upside, I have 50% more rifle teams than the light infantry company; downside I have 50% less heavy weapons with the missiles and machine guns pushed to company level instead of platoon.
Yeah, the drone prices...something like the Black Hornet Nano (pictured)
It lasts 20 minutes and has three cameras, and two of those, a control unit, and a charging unit costs between forty and sixty thousand bucks. That's just insane compared to the price of civilian drones; all I want is something with an phone camera or two on it to send back video to a ground station. I don't care if it's smartphone operated, I'm not looking for anything fancy.
At least the BMP-3 has its fuel tanks in a more logical place than the rear doors. It just strikes me as a light tank, and maybe a decent recon/counter-recon vehicle with its low profile and its firepower. I'd push it into that role and see how well it did myself, out of sheer curiosity. Forget carrying infantry, that thing's out there to hunt anything smaller than an MBT - and with its ATGMs, it can do that job too. Though I'll admit I think the 30mm autocannon is superfluous between the 100mm and the machine gun; get rid of your infantry and load that extra space up with ammo for the 100mm.
A look at Wikipedia brings up a weird variant, the BT-3F with
fourteen infantry onboard. Where the hell do they stick them? Even without the turret assembly (only an RWS) I can't imagine there's enough room for seven more troops in the thing. Bigger on the inside indeed; Slavic Space Magic strikes again.
I always liked the Stoner 63 and its modularity; it's just an old long-gone weapons system that has spiritual children in things like the Steyr AUG. Which I admit is something I'm still considering for the mechanized troops; it's got the same modularity and multipurposeness as the Stoner, and feeds M16 magazines just like the modified Beryls do.
The AUG has its HBAR and bipod configuration for a magazine-fed automatic weapon - it's not belt-fed, so it runs into the same short endurance problem the M27 IAR does. It wouldn't be a real weight savings, either, the Ultimax 100 only weighs 11 pounds. I think I'll stick with Beryls, and just give the mechanized infantry side-folding stocks to make their rifles more compact.
Cannonshop, you're right on the needs of a military service - the tricky part is balancing where "adequate" comes in. There's the Heinlein aphorism that the most expensive thing in the world is a second-best military. I'm just not sure I can afford being anything other than third-rate...
I wonder how much ammo is being carried by my rifle teams, especially with everyone carrying a spare drum for the LMG gunner and probably a spare RPG rocket as well...plus however many magazines they're issued. My mechanized infantry has the BTR to carry extra gear with, so I imagine they're hauling around a lot. I suppose a "standard load" would be six rifle magazines, two thrown grenades, two launched grenades, a drum for the LMG, and a rocket for the RPG. Give that to everyone in the team, mechanized or light, and load up the BTR-80 with extra party favors for its infantry.