Railgun project still alive.

[LaCroix]

Meanwhile the USN wants railguns to be kill all weapons firing hundreds of guided shells to essentially replicate what would take an alfa strike of F/A-18s with JDAM to otherwise accomplish and then rain down call fire for MARINES. It’d be brilliant if it worked but at this stage I’d be more optimistic at the chances of a 50,000 dollar cruise missile. But a small missile, however cheap, is going to be slow as balls and the shear speed of an artillery shell is a huge advantage.

It would be possible, if they use the liner-system instead of a complete barrel change. All the (moderately reliable) railgun designs I know use a system where the fortified barrel itself has an insert that will be changed every x shots. Of course, the navy will probably be using something more expensive than a copper tube, still, the question is the break-even point to an air-strike.

[Sea Skimmer]

US research is focusing in on solid lubricating compounds to line the barrel, including stuff based our old friend teflon. Its been claimed that test compounds have significantly reduced both arcing and mechanical abrasion; though it also sounds like you'd have to have a rammer swab out the barrel between every shot or few shots to replenish the coating, which is not really a deal breaker. I don't think anyone doing this work believes a militarily useful railgun is ever going to work without some kind of expendable coating, and likely both a coating and a liner which can be changed at sea. Of course it remains to be seen if these compounds will work in a full scale weapon in the first place, let alone well enough to actually resolve the problem. Our lack of a full desired power railguin naturally limits what can be done right now, but that's why railgun work is something that needs to be funded at a moderate level over a very long period of time to show results. For more essential work that tends to turn into the program going black so it need only be justified to a few top senators instead of the whole congress.

[Lonestar]

They tended to last 150-300 rounds. But that’s around 10 times what a rail gun will last right now.

As I was, for some reason I thought the expected barrel life of a railgun was 100 rounds.

[Simon_Jester]

I wouldn't be surprised if that's "expected" in the sense of "that's the specs of the Mk I blah blah blah Railgun, and you had better give me a gun with that barrel life before I put it on my ship." But they're still very slowly debugging this thing.

[LaCroix]

though it also sounds like you'd have to have a rammer swab out the barrel between every shot or few shots to replenish the coating

While factually correct, this sentence amuses me without end.
I think I found the schematics for the final design...

[ChaserGrey]

If you're shooting at stuff under the horizon and thus using a flat trajectory, I'd be worried about passthrough. I know that happened with AP shells on relatively unarmored targets using battleship guns, and those shells were going a hell of a lot slower than this thing would be. Be a damned awkward PR moment if your railgun shell wastes Ahmed the Awful, then passes *through* his boat to paste a fishing dhow. And another one after that. And then buries itself in the village they came from.

At least with ballistic trajectories, the only thing "beyond" your target is the Earth, which we may safely assume can absorb the projectile with minimal collateral damage.

Edit: I suppose we could turn the project over to Shroom and have him name it something like the "Serial Freedomizer", though. "It streaks through the atmosphere at hypersonic velocity, leaving a trail of pure freedom in vaporized plasma form in its wake!"

[LaCroix]

This gun is should be roughly the equivalent of an 155 firing similar sized projectiles, not the barrel-sized battleship grenades. Remember, it was meant to be used on the DDx Destroyer. I've heard theories that on impact, it would behave very much like a hollow charge from the energy released, and spray the inside of the ship with molten metal.

[ChaserGrey]

Yeah, and I've also heard pretty plausible arguments that a hypersonic impact will vaporize the penetrator pretty much instantly, leaving nothing to overpenetrate- although seems like that could go both ways, depending on how long what's left of the penetrator stays coherent.

[Sea Skimmer]

The speeds projected for this weapon, 2.5km/s objective, are not nearly high enough to vaporize an entire penetrator. However its expected that the primary shell type would be some kind of airbursting shrapnel round anyway. Unitary projectiles would be of more limited use for specific point target hard targets.

If a target is close enough to require direct fire nobody is going to give a damn about overpenetration, tough shit on anyone who sailed civilian craft within hundreds of meters of a naval battle involving major warships. It’s not like all the missiles and automatic cannon everyone is going to be blasting away with inside horizon ranges are exactly safe either. On DDX the secondary battery is a pair of 57mm guns firing 220rpm apiece for example. At any significant range the shell will be diving near vertically on the target.

If you want to worry about overpenitrtion then I'd worry a lot more about what existing 120mm tank gunfire does on land then anything at sea. Literally a 120mm sabot can go through all the buildings on a city block and fly out the other end; this has actually happened.

[ChaserGrey]

If you want to worry about overpenitrtion then I'd worry a lot more about what existing 120mm tank gunfire does on land then anything at sea. Literally a 120mm sabot can go through all the buildings on a city block and fly out the other end; this has actually happened.

My initial response to this was "bad-ass." Which probably makes me a bad person.

[Sidewinder]

If you want to worry about overpenitrtion then I'd worry a lot more about what existing 120mm tank gunfire does on land then anything at sea. Literally a 120mm sabot can go through all the buildings on a city block and fly out the other end; this has actually happened.

When and where did this happen? In Iraq, during or after the 2003 invasion?

[Sea Skimmer]

In Fallujah 2005; 120mm sabot and the 120mm obstacle reduction round, which is the HEAT round given a hardened casing went through whole blocks when fired into fortified buildings. The insurgents in the city fortified a lot of places by moving concrete jersey barriers and similar heavy materials indoors, then piling sand in front of them against the structural walls, so reason existed to think you needed something serious to crack them open…. those shells provided major overkill anyway. Stuff like this is why whole lot of buildings in the city just ended up being bombed, or else so damaged by direct fire they had to be bulldozed in the aftermath.

[D.Turtle]

Yeah, sabot rounds are ridiculously powerful. The safety range for firing real sabot rounds (aka not practice rounds) for the Leopard 2A6 is roughly 100 km (+/- 10 km depending on the source). There is almost no possibility to fire them anywhere in Germany.

[Simon_Jester]

You could fire them into a mountainside, no?

You just need a really tough target practice backstop.

[D.Turtle]

Nah, the German army simply went to Canada. I don't think they're still doing that because of the cost. Currently, tank training is on the low burner anyway, and the focus is on Afghanistan. I'd have to check my magazines in order to find out if they've gone to other countries in order to do real large-scale training in other countries (either Canada or the UK), but I don't think so.