/k/ - Weapons

>>323823

Light-gas guns firing scramjets would be better, if hypersonic missiles don't suit your tastes.

Railguns need really sci-fi materials to work, and those ought to be too expensive. Not to mention that the energy of the bullets isn't too much for the amount of energy you have to use to proper them.

>portable

Useless. Batteries are nowhere near as energy-dense as smokeless gunpowder, so you'd have to carry a giant-ass power pack on your back. Not only that, a good portion of the energy is lost as it's pushed through the wires, and all you get for your troubles is something not appreciably different from a conventional chemically-driven firearm.

>massive

Has some potential, because a stray shot hitting a capacitor bank is much less devastating to your vessel than a powder magazine going up. You still have to replace the barrel every hundred shots or so, but that isn't as much of an issue for vessels as it is for infantry in the field.

>hybrid chemical propulsion/rail-guns

wot. How would that even work?

>>323826

>wot. How would that even work?

basically, you use a regular bullet propelled by gunpowder, and use the magnets to accelerate the round.

>>323826

>hybrid chemical propulsion/rail-guns

>wot. How would that even work?

Maybe is just a more fancy way to describe an M4 with a railgun. After all, a gun has chemicals (gun powder), right?

>>323829

thats pretty much it

>>323829

thats pretty much it

>I haven't seen a thread on this topic before

We have them once a month.

Railguns, regardless of the size, are too bulky and too unwieldy to be real weapons.

The only reason their use is even considered on a ship, is because burning propellant is the main thing navies fear, the ship has an infinity of coolant (seawater) and little to no weight restrictions. A railgun eliminates the need for propellant, which is electrical instead of chemical.

It makes no sense anywhere else.

In terms or size and weight, raw performance parameters and multi-mission capabilities, railguns fall a distant last compared to combustion light gas guns and scramjet assisted shells.

>>323828

>>323829

You'd need to drop lead for a ferrous metal for the projectile, which drives up ammunition cost. And this doesn't accomplish anything you couldn't do by just using more powder per cartridge, so I don't see the point.

>>323828

Railguns work by passing a ridiculous amount of current through the projectile, which is usually made of iron or some other ferric substance. And no, to date, there's no way to circumvent the current around a projectile. Launching one also heats it to red hot.

So the projectile you're talking about would probably erupt in an instant explosion.

The only way this might be possible is a gauss gun, then some kind of rocket assistance.

>>323838

A Strelok was working on bolts for shotguns, then he disappeared. And I lost the pictures he uploaded.

>>323839

Probably nabbed by the AdMech for tech heresy.

>>323836

>there's no way to circumvent the current around a projectile

Except there is. You make projectile from non-conductive material (or use isolation coating) and apply conductive film to its rear side. Upon firing, film will immediately vaporize into ball of conductive plasma, which will be pushing the projectile. But yeah, assisted launch is a common practice with railguns due to how insanely intense the electric heating is.

>>323856

Pretty sure the conductive plasma would leak out instead of pushing it forward, or the projectile would still be overheated to the point of explosion.

Do you have any sources on this method?

>>323826

Batteries aren't the problem, it's capacitors. A standard lithium battery can hold 400+ w/h per liter or 1,440,000 joules.

If you have a capacitor that can hold one watt/hour that's only 3600 joules. However if you release one watt hour within a fraction of a second (let's say .025) the amount of energy spikes. Even with 10% efficiency from electrical energy to kinetic that's 28,800 joules.

Most likely it would get use as a barrel attachment on the muzzle of a precision rifle and using a conducting sabot with a subcaliber slug, eg a .308 that shoots .223.

>>323933

How would that be better than spicy paintball guns?

Surprised no one posted one of the several youtube videos about working rail guns.

>>323948

Coulda sworn I've seen 20mm that'll got through what's shown at 1:05 and keep going, while that looks like it's what 40-57 mm.

>>323865

Plasma would be contained by allowing it to generate its own magnetic bottle, which it does if made in a correct shape. The correct shape, as apparently with everything else thought to be sci-fi tech but actually possible, is a toroid. It would continue for some distance as a stable projectile in the toroidal configuration before it loses spin, destabilizes, and detonates/implodes in mid air.

With an electron laser, you could give the plasma projectile a clear path to follow. A properly charged target would be hit by both the hyperkinetic slug as well as the miniature star that threw it out the barrel. Scientifically possible today, given a power plant to fuel it.

There is a lithium based nuclear reactor roughly 3 times the size of current military generators that could do the trick, provided you could get Mitsubishi to build one in a relatively portable configuration rather than their conceptual underground neighborhood power plant design. The problem becomes cooling not just the gun but the reactor, but a peltier junction using the heat conductivity of graphene might work (assuming the current information about mono- and bilayer graphene films is entirely correct).

>>325162

What?

>>325168

You know when you try to find an answer to a problem on the interwebs, and then you hit a ten year old forum post from someone with the same problem, but there's no answers, the op only posts something akin to that he fixed it, without providing an answer.

It gives me the same vibes as your post about how bolter strelok slipped off the radar, and you lost the pictures.

/autmism rant

>>325171

Okay, I am in the same boat. I remember seeing these pictures once but for some reason never saved them.

>>325177

It does magnetise, though, it's paramagnetism, not ferromagnetism.

Everything else you said is right afaik.

>>323823

What does burnt powder weigh?

What does an empty battery weigh?

Consider the above for a moment and you might begin to understand why rail/gauss rifles still only figure in works of fiction. Until battery energy density is able to approach that of combustible propellant there is little possibility of electric firing mechanisms seeing practical application outside of shipborne platforms.

>>325177

Pro tip: use non-conductive projectile with tiny film of metal attached on the back. During firing, film will evaporate into plasma, which is conductive, and the plasma will push the projectile.

However you must go for strongest material, because the projectile is a penetrator. If it pulverizes upon contact with something solid it's worth precisely dick.

The only possible case for man-portable railguns that I can imagine anywhere in the near future is a small crew-served weapon designed to deliver an inert hypervelocity slug to a tank equipped with an active defense that detonates incoming warheads before impact.

Highly specialized, highly bulky, probably really expensive, but potentially an infantry platoon's only anti-tank option in a world with preemptive countermeasures on armor.

>>325166

>put on ship

>have a bunch of radiator fins with coolant running through them sticking a few meters off the bottom of the hull running along most of its length, transferring heat from the reactor into seawater

Cooling the gun would be much harder, but I don't think it would be impossible to run coolant between it and more radiator fins on the bottom of the ship

depending on how technology advances, thermal wakes could be a real problem though, and I would hate to be the guy who has to design the gun's coolant transfer system

Ships make very good platforms for otherwise unwieldy weapons

>>330607

It's not a propellant in the sense of an expanding gas pushing the object due pressure, but by being linearly accelerated via the Lorentz force.

I'm not sure if a plasma can actually push something solid though. I would think it would just go around it.

From what I am aware, current rail guns work with an aluminum sabot surrounding a tungsten penetrator. Since aluminum is light, highly conductive, and cheap, it works well in this role.

From explanations I've heard, the sabot should fly off the projectile as soon as it leaves the barrel (well rail) due to air pressure, BUT, if you watch actual test footage of rail guns, it looks like it has already vaporized by then, and an expanding gas (probably partial plasma) can be seen expanding behind the projectile.

This isn't surprising when you consider the insane amount of current involved.

Still, even though plasma is incredibly conductive, it's also insanely unstable and I would be surprised if it could be used to push things.

>>330176

Is this an actual method for propelling rail gun projectiles?

>>330176

So, depleted uranium penetrator with an aluminum backing?

>>323823

Coilguns are easier to make.