Guns! Guns! Guns! and GURPS

[Rupert]

Originally Posted by GURPS Fox

Funny thing about that, Battletech Endosteel has been proven right back in 2016 with metal foam composites. Sure it's V0.1, but it makes BT materials go from 'something that is impossible' to 'somewhat plausible' oddly enough. Hell, during the tests they pitted the composite against a .50cal BMG AP round and it did worse than the ball round...

Specialised AP rounds doing worse against some types of material than more 'basic' rounds is nothing new, and likewise some types of advanced armour doing worse than simpler types against AP rounds is nothing new either.

As for that armour - it's not Battletech-style ablative armour. For one thing, it relies on the very hard ceramic facing to stop or break up the incoming projectile and the foam to absorb the energy, so if the front plate is 'ablated' away it'll suddenly be providing far, far less protection.

Also, it was compared to RHA, which is not exactly the cutting edge of armour protection today. Heck, it wasn't even in WWII for many applications.

[GURPS Fox]

Originally Posted by Rupert

As an aside, if your opposite number's pistol (a backup weapon) can reliably punch through your armour, that generally means it's time to not bother with armour and use the saved weight to be more mobile and/or otherwise better equipped because the armour isn't doing anything much for you.

Only the helmet, mind you. The standard assault rifle is 34kJ/round in terms of Ke.

Also, armor, in the setting, caught up enough that it stayed viable.

Originally Posted by Rupert

Specialised AP rounds doing worse against some types of material than more 'basic' rounds is nothing new, and likewise some types of advanced armour doing worse than simpler types against AP rounds is nothing new either.

As for that armour - it's not Battletech-style ablative armour. For one thing, it relies on the very hard ceramic facing to stop or break up the incoming projectile and the foam to absorb the energy, so if the front plate is 'ablated' away it'll suddenly be providing far, far less protection.

Also, it was compared to RHA, which is not exactly the cutting edge of armour protection today. Heck, it wasn't even in WWII for many applications.

The odd thing is that what happened and what was described in the various sourcebooks and novels for EndoSteel more or less happened in that test, giving immense credence to Battletech armor not being out there, which is surprising to say the least.

[Rupert]

Originally Posted by GURPS Fox

The odd thing is that what happened and what was described in the various sourcebooks and novels for EndoSteel more or less happened in that test, giving immense credence to Battletech armor not being out there, which is surprising to say the least.

Projectiles breaking up on armour is not new. It's how the armour is (ideally) supposed to work in the case of face-hardened armour.

[GURPS Fox]

Originally Posted by Rupert

Projectiles breaking up on armour is not new. It's how the armour is (ideally) supposed to work in the case of face-hardened armour.

From what I understand, yes and no. At least, not to the point that Battletech armor does.

[weby]

Originally Posted by Ulzgoroth

GURPS does address HEAT countermeasure technology. And they do tend to be ablative. Usually a bit more violently ablative than your basic 'ablative armor because that makes it a convenient hitpoint system' models on though.

Very much this. In GURPS the maximum extra protection you can get vs HEAT is laughable compared to real.

Basically HEAT has great penetration against many simple materials, but it is very easy(comparateive to other types of armor designs) to build protections that reduce HEAT penetration by a large factor compared in armor weight, though most of such tend to be fairly bulky.

[Rupert]

Originally Posted by weby

Very much this. In GURPS the maximum extra protection you can get vs HEAT is laughable compared to real.

GURPS says that composite armour is twice as effective vs HEAT as normal armour that gives similar protection vs normal attacks. This is about what's estimated for modern composite armour in real life, and is generous for earlier composites, even western composite armour (which was supposedly a lot better than Soviet composite).

[Fred Brackin]

Originally Posted by weby

Very much this. In GURPS the maximum extra protection you can get vs HEAT is laughable compared to real.

Basically HEAT has great penetration against many simple materials, but it is very easy(comparateive to other types of armor designs) to build protections that reduce HEAT penetration by a large factor compared in armor weight, though most of such tend to be fairly bulky.

The rule of thumb is that composite armor is 2x as effective agaisnt HEAT compared to simple materials and that might seem like a lot but HT and it's extremely careful research says that the 6x9(10) missile I mentioned earlier will _easily_ penetrate a T-72. Adding Reactive Armor Plating won't be enough to stop it either.

<shrug> You can postulate hypothetical futre armor that is not just "comparatively good" against HEAT bt good enough to stop it. However, the range you need isn't 2x as good. It's more iike 30x.

[Rupert]

Modern ATGWs of the 'man portable' and 'vehicle' size (as opposed to huge helicopter/drone mounted things like the Hellfire) seem to have about 1200mm penetration, after reactive armour, or so their manufacturers claim. That's 6dx16(10).

Modern kinetic energy tank gun rounds seems to be about 850mm+ (1000mm+ if you believe the Russians), or about 6dx57(2).

Declaring modern composites to be hardened vs HEAT means the DR can be set to stop HEAT rounds whilst still being vulnerable to AP rounds, which seems to fit current expectations (depending on how good the latest reactive armour is vs the latest AP ammo).

The real problem for tanks in modern warfare is that it doesn't look to be going to be about large conventional battles any time soon, and in the sort of fighting we're seeing the inability to armour the sides and top of tanks vs any serious anti-tank weapon is a major weakness. It also means that old tanks like the T-72 continue to be very useful, as they are just as well-armoured over the non-frontal arc as most modern tanks (and thus just as proof against near-misses by artillery, anti-personnel weapons and so on) and there's nothing wrong with their gun, especially for firing HE shells in support of infantry.

[Fred Brackin]

Originally Posted by Rupert

T in the sort of fighting we're seeing the inability to armour the sides and top of tanks vs any serious anti-tank weapon is a major weakness. .

More like unable to armor v. any casual anti-tank weapon. The modern HEDP is 7D(10). That needs 245 DR to stop unless composite or 123 if composite. .

[Rupert]

Originally Posted by Fred Brackin

More like unable to armor v. any casual anti-tank weapon. The modern HEDP is 7D(10). That needs 245 DR to stop unless composite or 123 if composite. .

As that usually can't be fired onto the top (though with a good ambush in a built up area it can be, of course), a T=72 with skirts is fairly safe from it (it won't penetrate the turret sides, and with a skirt it shouldn't penetrate the hull sides either). But point taken, given even old RPG-7 warheads will go through the side of any tank's hull (and many tank's turret sides) unless they've got mesh or skirts (and sometimes even then) and there are ridiculously large numbers of those around, to the point that they aren't a 'serious' anti-tank weapon, and an 'all the time anti-everything' weapon.