Short Range Shotgun: Averted. Flipping the switch on either standard model of slugthrower (pistol or carbine, turning it into a shotgun-analog, sawed-off and regular respectively, by firing multiple flechettes in rapid succession while flaring the fields at the end of the mass driver to achieve spread), or firing canister shot from a sluggun, does nothing to turn down the power. If anything (if you don’t manually drop the power to get low penetration, that is) they’re even more lethal than regular shot out of the same weapon, and equally effective at range. With the advantages of spread on top of that.
Our Weapons Will Be Boxy In The Future: Averted in most cases; most guns, while still being fundamentally gun-shaped (ergonomists cringe at the thought of trying to actually hit something with the remote-control-styled ST:TNG phaser, for example) as appropriate to the manipulators of the species they’re designed for, still follow The Aesthetics of Technology in being sleek, curvy organic shapes. After all, they’re nanofactured – grown, not assembled – and all the field-replaceable parts are modular, so…
Played absolutely straight in just one case by the S-11i Mamabear heavy sluggun, because the Mamabear is a brutally overpowered weapon designed – well, the designers appear to have been thinking about building a weapon to fight kaiju at close range. It looks like a large vaned metal brick with a stubby barrel sticking out of one end because that’s precisely what it is; the mass driver is sufficiently overpowered that the whole mechanism of the thing is built into a giant heat sink to keep it at something close to a reasonable operating temperature. Although if you fire the thing multiple times in close succession, reasonable operating temperature means “only radiating in the red”.
(It has some other disadvantages too, like small magazine size, slow reloading rate, inaccuracy at long range, and a recoil that inflicts compound fractures on anyone who fires the thing whose bones aren’t reinforced with hard-wearing synthetic composites, but sometimes that’s worth it for the ability to one-hit kill damn near anything you’ll ever find yourself staring down the barrel at.)
One-Hit Kill: Your mileage will almost always vary, given the amount of variant tech out there, but a sluggun – and the S-11i Mamabear in particular (see: BFG) – will do this to most regular infantry (they are, after all, designed as anti-materiel weapons), and one in which you put antimatter-grenade slugs will one-hit kill just about anything… assuming you’re in the sort of war and on the sort of battlefield where they let you use weapons like that, which tends to be the problem there.
Only a Flesh Wound: Averted. Sure, modern transsophs have all kinds of enhancements for durability and healing – smart cardiovascular nets, auxiliary hearts, better blood clotting, etc., etc. Those will help you if something slips past equally modern milspec combat armor with full kinetic barriers, or against a (very) glancing hit or ricochet, or against car wrecks, or shrapnel, or stabbing, or being on the fringe of an explosion.
But a mass-driver gun tosses target-customized flechettes downrange at appalling, air-plasmating, entirely excessive velocities. If you get hit directly by one of those without armor, or with enough of them to overcome its protection, it’s a bone-pulverizing, flesh-pulping experience that is almost certainly not survivable – and there’s no safe place to be hit.
If they bring up the heavy weapons or go to full-auto, it’s all over bar picking the vector stacks out of the slightly-charred chunky-salsa-esque ooze.
Since in the ongoing series about the Legions I’m obviously going to be talking about their guns, seems to me that I ought to maybe describe the terminology used for those just a bit so that you know what I’m talking about.
That is, inasmuch as terminology has changed from what could reasonably be translated into our firearms terminology, inasmuch in turn as these guns technically aren’t firearms – they’re powered by mass drivers rather than chemical explosions – so while some of the words are familiar, the definitions have changed.
Let me sum up:
There are four basic classes of guns (in the slugthrower sense, that is, and ignoring needlers which no-one counts as slugthrowers even though they technically are) used in the Empire. These are referred to as pistols, carbines, snipers, and slugguns.
The first three of these all work by firing tiny flechettes at HOLY CRAP speed.
A pistol is, basically, any flechette-firing mass-driver handgun.
A carbine is the common flechette-firing mass-driver long gun. The original definition as “shorter-barrelled than a rifle” has more or less gone away, since there are no more rifles – the mass drivers spin their projectiles purely through EM fields – but it translates to the vast number of general-use longarms intended for use in pretty much all combat situations from close-up defense to long-range suppressive, essentially filling both the PDW and assault rifle role.
A modal example has a bullpup configuration and probably has a form factor not dissimilar to the FN P90, the weapon I would expect to play them on television if any of this were ever to be made into television. The barrels, in general, are not significantly longer than the main body.
A sniper is the only really long longarm, long-barreled and equipped with specialist software and sensors for even more accuracy than you’ll get out of an already accurate carbine. They’re the descendants of sniper rifles, only shortened in name because, well, they’re not rifles.
The sluggun isn’t a flechette weapon; it fires macroscopic metal slugs in an anti-material role, or canisters which you can put just about anything in, up to and including using it as a launcher for bore-compatible grenades and gyroc micromissiles.
A battle carbine isn’t a special class of its own; it’s what you get when you mount a regular carbine and an underslung sluggun in the same case for maximal versatility, usually sharing their redundant components.
Of our other common firearm types, this can be said:
There aren’t shotguns, because a simple software change to a carbine can emulate them by firing a burst and oscillating the final stage of the mass driver to produce a spreading cone of flechettes, with all the stopping power and spread of the real thing. You can do the same thing with a pistol to emulate a sawed-off shotgun. Alternatively, you can fire canister shot out of a sluggun to much the same effect.
There aren’t submachine guns, because you just configure your carbine to fully automatic rapid fire, and you have exactly the same effect. Likewise, the machine pistol and the pistol.