Recently, I was lying awake at night and as usual, my mind strayed towards Halo, specifically, the exact operation and ammunition of my two favourite Covenant weapons; the Covenant Carbine and the Fuel Rod Gun. A number of excellent blogs before this have explored the mechanism of Covenant Plasma weaponry, shields, and the Spiker, so I thought, why not?
The Covenant Carbine fires caseless radioactive projectiles, shot at supersonic speeds into the target. In addition to the kinetic damage they cause, similar to a modern bullet, they are also roasting hot and radioactive, so as well as having your body ripped open, you will also be cooked from within by the intense radiation if you can't get the slug out. Furthermore, when the Carbine's magazine is depleted, it shoots out in a cloud of noxious gas that according to one Marine, can give you Boren's Syndrome. I thought long and hard about how this might be possible. What kind of exotic ammunition could the Covenant use that can have all these effects? And then it hit me; there's no handwavium or Forerunner materials involved, in fact, they use a substance we've known about for years.
They use depleted uranium.
Infamously used by allied forces during the Gulf and Iraq Wars, D.U is is an incredibly tough, pyrophoric material used in kinetic energy penetrators, so when it hits a target, it not only bursts through armour, bits of it also fragment into dust that ignite in air and normal temperatures, so not only do you have a bit of uranium in you, it's also on fire. It was used to destroy tanks in the Gulf War, and given the Covenant's technological level, I see no reason why they shouldn't have miniturised it for anti-personnel duty. D.U is also weakly radioactive and toxic to Humans, having nasty effects on the brain, heart and liver, so you can see its advantages in the Covenant's eyes.
And now onto the Boren's Syndrome-inducing gas the Carbine supposedly releases. D.U's effects on the brain, resulting in decreased performance on neurocognitive tests and headaches, as well as increasing the risk of cancer, have some similarities to the symptoms of Boren's Syndrome, which include memory loss, migraines, and brain tumours. It was found during the Gulf War that the firing of depleted uranium munitions creates an aerosol that, if breathed in, will remain in the lungs for some time. It's not unreasonable to imagine that igniting the propellent that fires the Carbine's slug will cause some of the D.U to vaporise and remain in the weapon, which would be released when the empty magazine is released and potentially entering the user's lungs.
And so to the Fuel Rod Gun, which apparently operates on a similar system to the Carbine. My belief is that when one of the "Fuel Rods" is launched, a starter motor soft-launches it out of the weapon (similar to the RPG-7 of FGM-148 Javelin), avoiding a massive backblast and getting it to a safe distance before the rod's primary rocket engine (or Covenant equivalent) activates and sends it on the rest of the way to the target. When it gets near to the target, an explosive charge within the rod detonates, melting a small quantity of depleted uranium and forcing it into a "spear" of molten metal that rapidly solidifes and crashes straight through the target, causing penetration and pyrophoric effects similar to a modern kinetic energy penetrator. Given the small size of the rods, you might think that this isn't powerful enough to take out a Main Battle Tank, but the Fuel Rod Gun is defined as a Light Anti-Armour Weapon, design in the same vein as the UNSC's family of SPANKR rocket launchers or the modern SMAW or AT4; it's designed for use against buildings or light armour and can't take out a tank without hitting it in exactly the right place (back, underside, or flanks). Have you seen how many "Fuel Rods" it takes to knock out a Wraith or Scorpion in-game? That's what I'm talking about.
So, there you have it, my mildly interesting dissertation on the Covenant Carbine and Fuel Rod Gun. Your opinions and input please, but nothing on the ethics of the use of depleted uranium in warfare. I'm neither condoning nor supporting its use, just presenting an idea. And to prevent the blog going off-topic, nothing about whether Boren's Syndrome is real or not, either. Cheers!