Shoot All Week

Another gun post. Title's a reference to the Henry repeater, "the damn Yankee rifle they load on Sunday and shoot all week." It's a pun: "repeat" and "firearms", i.e., another gun post.

• Had occasion to get down to brass tacks about my coil vulcans. The man-portable, three-barrel ones fire relatively standard HEIAP ammunition with ferrous-metal "driving belts" (which some modern .50 caliber machinegun rounds seem to have), to give them 20-millimeter performance in a 13-millimeter package. The six-barrel ones mounted on aircraft are 30 millimeter, basically a magnetic version of the GAU-8 or GSh-6-30.
  
  Instead of "spinning up" electrically, like most American vulcans, or via gas, like the Soviet ones, I think 24th-century coil vulcans actually do it with their recoil—and given a 390-gram 30-millimeter round at 845 m/s has a muzzle energy of 139.235 kilojoules, the recoil is considerable. You might as well get some use out of it. (Yes, you can use recoil to spin part of a gun; the Mateba and Webley autorevolvers did it, along with cocking the hammer.)
• The coil-vulcans mounted on battle-spacecraft ("starfighters") are only 5.56 millimeter, because they go at 1% c and mass only 4 grams, the same as M855 "ball" M16 bullets. The kinetic energy calculator says the muzzle energy for that is 4.3 megagrams of TNT.
  
  You can counter part of that with a soft recoil system, but that usually only halves the recoil energy, so you're still talking about slamming the vessel with just over two tonnes of TNT every time the thing fires. Maybe those ones spin up electrically, and the topological inertia protections keep the guns from tearing the ship apart.
  
  Ooh, I like that. The topological protection would cause huge "muzzle flare" for the people who use topological sensors. (Since they use metric-patching guns, their own weapons are equally detectable, if not more so.)
• Brought back bayonets on zled lasers. Since my favorite weapons are halberds, thought I'd have their bayonet be heavy, for chopping as much as stabbing. The shape would be a bit like a skeggöx "beard" (some of which came to a point), upside-down and at a somewhat different angle.
  
  The bottom half of the hexagonal prism that forms the outside of zled lasers has an accessory rail set in it, something like the Smith & Wesson TRR8 . The bayonet attaches to the rail, rather than with a special lug or socket. They don't need a laser-pointer, because laser weapons can be used for their own, by using the same optics as the weapon does: the dot you're sighting with suddenly explodes. (You can also use the laser's optics for a scope; zled lasers have a little panel that pops up under the rear sight to show a reflex-image of the laser-optics picture.)
  
  Their long lasers are 117.7 centimeters long, of which 91.4 cm is the optical cavity. That's the equivalent of a human having a gun 97.7 centimeters long—and remember, they wear their lasers like swords. 97.7 centimeters is about seven centimeters shorter than the M1860 light cavalry saber.
• Decided my zled anti-materiel laser does about 30 kilojoules; it's about five thirds as strong as the .50 BMG we use in our anti-materiel rifles, and about three-fifths as strong as the 20×110 millimeter round used in the strongest anti-materiel rifles currently in existence.
  
  The normal zled laser is 10 kilojoules, which is high for an infantry weapon but not unreasonably, for a society where all soldiers wear armor (also where they don't have to worry about recoil). I have the anti-materiel laser use the same power-cartridge as the normal ones; it just goes through them three times as fast.
  
  The anti-materiel ones are basically the same shape as the standard ones, but their lenses are wider, so they can focus at a longer range.
• The laser equivalent of machinegun fire is continuous-beam; burst-fire is presumably a brief zap for a set period of time. Since for optical wavelengths you have to pulse the zaps, you can talk about the "burst" in terms of the number of pulses.
  
  Whether "burst" or full auto-fire, the main way you use it is to keep the enemy behind cover while your allies advance, just like machinegun fire. As anyone who's played Reach (at least on Legendary) will tell you, continuous beams are just as likely to make you keep your head down as a machinegun is.
• I think I've pointed out that the oft-quoted "shots per enemy kills" numbers don't actually show anything about "reluctance to kill", they show use of suppressive fire. Besides, we don't actually have a way of tracking how many rounds have been fired; at least some of those "shots" stats actually use "rounds shipped over" (e.g. to Vietnam) as a proxy measure for "rounds fired"—never mind they're two quite different things.
  
  But apparently, one of the major studies often cited in support of the "reluctance to kill" interpretation, the famous one by Brig. Gen. S. L. A. Marshall, was, at best, deeply flawed...if not fake. Apparently Marshall didn't even actually ask the people he interviewed the questions he claimed to be answering—as in "how often did you fire?" or "how often did you actually shoot to hit the enemy rather than just at him?"
  
  Of course, none of that changes the fact artillery, not small-arms fire, is the main killer on battlefields. There was a reason Stalin called it the God of War. (Well, in premodern war, dysentery was the main killer, but the only people who'd name that "God of War" are Nurgle's Plague Marines.)
• This paper (Google the title to find the article as a pdf) says it takes 6 megajoules to accelerate an 18-kilogram projectile to 420 m/s. Now, .50 BMG Raufoss, like the coil-vulcans basically shoot, has a muzzle velocity of over twice that—915 m/s—which comes out (if it scales linearly) to 13 and 1/14th megajoules. Of course, the projectile masses only 43 grams, not 18,000, which (agaim, assuming linear scaling) means a power-requirement of 31,226.1905 joules. That means to power the coil-vulcan for 1000 shots requires a silicon-air battery massing only 1.65 kilograms.
  
  Late addendum: The GSh-6-30 shoots 390-gram bullets at 845 m/s. That would mean that firing each shot takes 43,591.2698 joules, which, assuming 1,350 rounds (the maximum capacity of the A-10 Thunderbolt) requires a silicon-air battery of 1,148.75 grams. That's about the size of a motorcycle's battery.
  
  The aircraft autocannon's battery is smaller than the "1,000 shots at 31 kilojoules" battery because I did the first one backwards, and divided the battery's energy density by the power requirement instead of the power-requirement by the energy density. The correct battery size for the 13-millimeter coil vulcan would be 609.55 grams, the same as a lithium-ion battery used for power-tools nowadays.
• Zled uniforms are armored; they can block the "sidearm" hand lasers up to pretty close (within about thirty meters, typical "battle zero" for the Beretta M9; up to ten meters, they keep the wound smaller, reducing the bleeding), and at least are better than "exposed skin" against the long laser (so it's only lethal out to, say, half a kilometer instead of a whole one). The interesting thing is, the main way the uniform is armored is it's got a layer of energy-dissipating stuff sandwiched inside it, peeking out at the ruffles on the cuffs; the cuffs glow when the uniform has to dump a lot of energy.
  
  Zled powered armor isn't just powered in terms of lifting assistance (which, given it's designed for people who can lift several times their own weight, is really just "cancel out its own weight and that of any other equipment"). It's also made of "smart" material, adjusting its molecular structure to cope with any attack. The only way to get through is to hit it with too much to cope with at once; zled long lasers can do it by hitting from about 150 meters away, their hand lasers from about a sixth that. Humans do it with anti-materiel rifles or actual anti-tank grenades.
• If the Serdyukov SPS is the future-y Makarov, what's the future-y version of the M1911 (America's service pistol for most of the Makarov's run)?
  
  My vote is the Detonics Defense MTX, an entry for the Modular Handgun System competition for picking the M9's replacement—which somehow manages to be a 10(+1)-round M1911 while still being .45 ACP.
  
  If one wanted a futuristic M9 (America's service pistol when it won), I would go with either the Px4 (P×4?) Storm, or possibly the 90two. Probably the first one, just to punish the 90two for its stupid name.