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 Grey Templar wrote:

Slipspace wrote:
They're talking about adding "rifling" by creating a spiral magnetic field to help stabilise the projectile and many of the limitations are due to technology not being advanced enough yet.

That is an overly complicated solution. Just make ammo with stabilizing fins. Spinning magnetic fields is way way too complicated. Treat the problem like modern smoothbore tank cannons. If you can't have rifling, make the projectile have fins.

This. It's not like you need a solid barrel with a railgun, and the projectile doesn't touch the magnets anyhow. You can do all sorts of things to its geometry that bullets can't get away with.

At best, you are introducing a potential point of failure by having spinning magnetic fields. If they are/become misaligned it will hopelessly destabilize the projectile.

But on the up-side, think of the marketing potential

You could probably describe it as a quantum leap, and even add a dash of nano-whatever!

And the flashy computer renders! Think of the possibilities!

Doesn't really matter if it "works", does it?

There are two very distinct technologies being described here. Ian of Forgotten Weapons talks a little more about the differences in an interview with the owner of ArcFlash.

The gun in the OP is a coilgun. It uses a sequence of magnetic coils to attract the projectile in sequence. There is no contact between the projectile and the coils, so the projectile can be essentially any shape so long as it is ferrous or encased in a ferrous sabot. Coilguns are bulky, electronically complex (since there's a switching function needed to control the coils), and inefficient, but are low-maintenance and suitable for amateur and low-cost electromagnetic propulsion.

A railgun, on the other hand, uses two conductive rails with the projectile (or sabot) physically touching them. A current is passed through one rail, across the projectile, and through the other rail, and the Lorentz force accelerates the projectile. Railguns are mechanically simple. However, they're constantly in a state of trying to blow themselves apart during operation, and suffer quick degradation in use. The massive fireball you see on this US Navy railgun test is the material of the rails ablating:



The biggest advantage to electromagnetic propulsion is that it's not velocity-limited by the expansion rate of combusting gas. The biggest problem is that it's easier to electromagnetically propel a heavy, slow projectile than a light, fast one, since a slower projectile spends more time in the 'barrel' and can ends up with more energy for a given transfer rate. Achieving a higher muzzle velocity requires more power dumped more quickly under higher stress, and that's where it's pushing the state of the art.

That's why the ArcFlash coilgun lobs a heavy slug and a downright sedate velocity, while the Navy railgun consumed half a billion dollars over fifteen years before being canned. Making electromagnetic propulsion genuinely attractive over conventional propellants will require either significant advances to capacitor technology in a coilgun application, or finding a way to minimize the wear-and-tear on railguns, and both also need denser power storage and faster energy transfer before they can displace conventional guns outside of niche applications.

It's a super cool couple of technologies, but chemical propellant is a very refined technology, and electrical power storage and discharge has catching up to do before it can make electromagnetic propulsion truly practical.

 Mad Doc Grotsnik wrote:

 Laughing Man wrote:

 Mad Doc Grotsnik wrote:

 Ahtman wrote:

 Mad Doc Grotsnik wrote:
It doesn’t go pew or dakka.

I am intrigued, but disappointed it doesn’t go pew or dakka.

It does not spark joy in da boyz.

Indeed it does not! It does however, rather disconcertingly considering it’s a deadly weapon, sound like a Nerf gun.

That would be because it's laughably subsonic. You could probably get a faster dart out of a souped up nerf gun.

Because I’m all well clever and smart and totally understand all guns in all ways?

I’ll settle for a “wom wom wom womwomwomwomwomwowmowom” as it’s charging up!

According to one of FW's other videos, it does go vooooooooooooooOOOOOO as it charges