Naval rail gun, mv 4,500 mph

Very interesting technology being developed,
But I doubt I will see in my lifetime a railgun and power source that can pack as easily as a ruger 10/22 and a couple of bricks of .22lr

I have to wonder what an EMP would do to the electronics of that weapon. I suppose you could apply enough shielding to protect it. I agree with Kendal Black's statement that battery technology has always and continues to hold us back. Look at all of the Galaxy phones that have burst into flames. Do you guys know what BAE stands for? Most pilots will tell you it means - Bring Another Engine.

Been seeing this for a good while.
I want to see hits ten miles away, not "one ragged hole at five yards" equivalent.

Crazy about all the smoke coming out, and sparks. Wonder where they come from?

Burnt off the rails and sabot most likely. "Barrel" life may not be long.

Kendal Black said:

http://www.mirror.co.uk/news/weird-news/military-tests-new-game-changer-10073014?service=responsive

You thought your Super Belchfire Magnum's muzzle velocity was impressive?

Battery technology will need to get better before electromagnetic guns are replacements for the chemically powered rifles we now use. There will be big advantages. You will be able to dial your rifle's power level seamlessly from squirrel to big game. Ammo will be just the bullet, greatly simplifying supply and manufacturing questions. The lack of a backpressure pulse will change how guns are designed.

That's science fiction for now, but so far as cannon type stuff the Navy seems to be on top of the matter.

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Still 1,000 fps slower than an M256 120mm, and the ammunition is cheaper.

Since, the law of conservation of momentum is still valid, you still have to deal with recoil and all that that brings with it.

as soon as these things have a decent barrel life they may start using nuclear powered destroyers to run them, effectively bringing back battleships. Fun stuff. As for small arms, it may very well happen

All I can think of.

Kendal Black said:

http://www.mirror.co.uk/news/weird-news/military-tests-new-game-changer-10073014?service=responsive

Battery technology will need to get better before electromagnetic guns are replacements for the chemically powered rifles we now use.

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"Battery technology will need to get better before electromagnetic guns are replacements for the chemically powered rifles we now use."

They do not use batteries. They use capacitors, which can discharge quickly.

lysanderxiii said:

Still 1,000 fps slower than an M256 120mm, and the ammunition is cheaper.

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Railgun ammo is cheaper; it is just a solid chunk of metal.

Railgun muzzle velocity is 7,877 fps...about 2000 fps faster than the M256.

Flechette said:

Railgun ammo is cheaper; it is just a solid chunk of metal.

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I hope so, IIRC current APFSDS rounds are $10,000+ each. Eliminating everything but the projectile (but probably keeping the sabot component) should bring the cost way down.






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Still waiting on my LGS to get a shipment of EM-1s in, for some reason they are still back ordered.





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Flechette said:

Railgun ammo is cheaper; it is just a solid chunk of metal.

Railgun muzzle velocity is 7,877 fps...about 2000 fps faster than the M256.

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An all up round of M829A3 cost about $8500.

A projectile for the rail gun is $25,000.

Maybe the price will come down with volume production....

Imagine the velocity you could get out of that thing if you handloaded for it! I'm sure that the standard loads they shoot are probably anemic lawyer-loads.



(Admit it. You know that you were thinking it at least for moment. Or maybe I'm just weird. They aren't necessarily mutually exclusive options.)

4,500 mph = 6,600 fps

morcey2 said:

Imagine the velocity you could get out of that thing if you handloaded for it! I'm sure that the standard loads they shoot are probably anemic lawyer-loads.

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The 50th Edition of Lyman's is out. I'm sure it has load data.

If I remember right, in the original testing they were using 3" styrene rods wrapped in iron tape and getting 8-9,000 fps, and that was back with hihg voltage 3 phase AC current driving the coils (barrel lengths were around 40 foot, too).
Going to DC powered capacitors lets you use a much lower current, and a shorter barrel.

Downside being, there's not a very good way to evacuate the bore, so all the air in the barrel ahead of the projectile compresses pretty seriously as the projo gets to 6-6600fps--all that decompressing air leaves a rather significant "smoke" signature at the muzzle, too.
For shipboard use, they are already projecting some serious needs for overpressure and sonic protection around the muzzle arc.

My understanding was that the original "ideal" round was going to be a 1:15 to 1:17 penetrator with fin stabilization in a ferros metal "enameled" ceramic sabot. Fin stabilization is required as the round magnetically levitates into the center of the coil axis, and does not actually touch the bore at all. (In an ideal situation.) I remember everyone boning up on their physics so as to be able to compute kinetic energy effects with the penetrator rounds. The folks over at General Dynamics were having some fits getting an explosive payload round that was suitable for railgun launching. Which has become a huge budget issue for the Zummwalt class of ships.

Now, back to more on-THR topic, I remember that there was some research for "personal" sized rail/coil guns, where a chemical charge was sued to drive a helical magneto to generate the burst of current to run the capacitors up. The idea was to then hold the exhaust gasses, then vent them out the muzzle--a reverse gas port if you will--just before the projo is fired, to help evacuate the bore. Which would be a little like a cordless nailer, which uses propane to power the compression stroke which drives the nail rather than compressed air. Those researchers were clearly under-educated on the trevails of lock time, though.

mjsdwash said:

as soon as these things have a decent barrel life they may start using nuclear powered destroyers to run them, effectively bringing back battleships. Fun stuff. As for small arms, it may very well happen

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Exactly. That's why they're mounted on Naval vessels.

On a ship it is not hard to have really big generators and capacitor banks. Plus you are not storing a bunch of flammable gunpowder and explosive warheads on board. The really big advantage of rail guns that is often not understood by lay people is that every target regardless of range is only about 10 miles of air resistance away (equivalent to 5 miles twice).

Mike

These guns are interesting and should be devastatingly effective. Running these guns at their full rated power with the right projectile you can probably fire fractional-orbit intercepts- meaning that with good enough fire control you could shoot a satellite out of low earth orbit...

Hey cap, would it be possible to vacuum seal the bore with a disposable end cap that would be penetrated by each shot? Would this be worth the trouble?

1KPerDay said:

Hey cap, would it be possible to vacuum seal the bore with a disposable end cap that would be penetrated by each shot? Would this be worth the trouble?

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You would run into a wall of air at Mach 5-7 right outside the barrel. I'm not sure how big a problem muzzle flash in a modern navel engagement (mostly beyond the horizon). Did the Big Naval guns ever use triple base anti-flash powder like land based artillery? I don't know, so I'm asking.

Mike