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Old 05-21-2009, 02:18 PM   #11
SuedodeuS
 
Join Date: Sep 2008
Default Re: Explosive Bullets

Thanks for steering me toward the Mk 211. That is definately the way most explosive small-arms rounds should work - pyrotechnic incendiary to ignite the HE charge. A fuse would simply be too heavy.

Having looked up some more information on the HEAT warhead, I think I have a decent idea of how it functions. I can see why it isn't used for anything lower than 20mm (initial warhead size has a huge impact on penetration depth), but I'm having difficulty seeing why it couldn't be used in smaller rounds. Is anyone aware of a reason it might not be possible? I could see it having the same problem as other high explosive rounds - weight of the fuse - but shouldn't it be possible to use a similar mechanism to the Mk 211? If HEAT can be scaled down for small arms, what kind of effect should it have on damage? I can see it scaling down damage type one or even two categories (so pi++ goes to pi+ or even just pi), due to the "fist to finger" reduction of the penetrator's effective size. Of course, the copper jet's dispersion might end up bringing this type right back up...

EFPs seem to be rather similar to HEAT, but with a different shape to the copper liner that causes it to form a kinetic penetrator rather than a jet. If HEAT can be downscaled, so too should EFP. Of course, using it to allow a secondary attack with a missed bullet is well within the realm of cinematic (realistically, wouldn't the bullet have to tumble midflight and reorient itself for such an effect?). Regardless, EFP should certainly downgrade damage type, as the penetrator is going to be a good deal more narrow than the initial round. Now, small arms are unlikely to be used against reactive armor, meaning HEAT would likely be preferable to EFP. However, essentially any small arm (other than a shotgun) worth using is going to have a rifled barrel, and the HEAT jet doesn't get along very well with spins. I think it's possible (correct me if I'm wrong here) to have a sabot that will prevent rifling from imparting a spin, but in that case you're dealing with a sub-caliber round with degraded accuracy. I don't see any reason as to why EFP would have difficulty with a spin, however, as its penetrator is a solid chunk of metal. Thus, EFP would allow you to use a full-caliber round that is just as accurate as a typical round, making it competitive with HEAT.

HESH is a bit more problematic. First of all, it needs a delayed effect, meaning that it may be impossible to work around the need for a fuse. Secondly, I suspect it would be mostly useless. Modern (and presumably future) infantry armor is primarily flexible, with some hardening in important areas. As Kevlar has actually been used as a spall liner, I suspect infantry armor wouldn't be a very good conductor for the HESH's shockwave. Powered armor would likely incorporate lightweight, flexible materials in no small fraction as well, essentially making them come by default with spall liners. Now, against unarmored (or very lightly armored) opponents, it might be rather nasty - probably essentially HP (increase damage category) with a nasty follow-up explosion. So, great against zombies (and most other corporeal undead I suspect), useless against soldiers.
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Old 05-21-2009, 02:37 PM   #12
Ulzgoroth
 
Join Date: Jul 2008
Default Re: Explosive Bullets

Quote:
Originally Posted by SuedodeuS View Post
Having looked up some more information on the HEAT warhead, I think I have a decent idea of how it functions. I can see why it isn't used for anything lower than 20mm (initial warhead size has a huge impact on penetration depth), but I'm having difficulty seeing why it couldn't be used in smaller rounds. Is anyone aware of a reason it might not be possible? I could see it having the same problem as other high explosive rounds - weight of the fuse - but shouldn't it be possible to use a similar mechanism to the Mk 211? If HEAT can be scaled down for small arms, what kind of effect should it have on damage? I can see it scaling down damage type one or even two categories (so pi++ goes to pi+ or even just pi), due to the "fist to finger" reduction of the penetrator's effective size. Of course, the copper jet's dispersion might end up bringing this type right back up...
Ultratech stats small-arms (or relatively-small arms) HEAT (and HEDP) as doing imp damage, if I recall.

I have doubts about replacing the fuzing with a simple impact-ignition thing for HEAT. A HEAT warhead needs to detonate at a short standoff distance from the surface to be penetrated, which means the trigger has to be stuck out ahead of the main charge. And I don't know, but I imagine the effect might be sensitive to just how you ignite the main charge, making the assembly more complicated.
Quote:
Originally Posted by SuedodeuS View Post
HESH is a bit more problematic. First of all, it needs a delayed effect, meaning that it may be impossible to work around the need for a fuse. Secondly, I suspect it would be mostly useless. Modern (and presumably future) infantry armor is primarily flexible, with some hardening in important areas. As Kevlar has actually been used as a spall liner, I suspect infantry armor wouldn't be a very good conductor for the HESH's shockwave. Powered armor would likely incorporate lightweight, flexible materials in no small fraction as well, essentially making them come by default with spall liners. Now, against unarmored (or very lightly armored) opponents, it might be rather nasty - probably essentially HP (increase damage category) with a nasty follow-up explosion. So, great against zombies (and most other corporeal undead I suspect), useless against soldiers.
But why use it there instead of conventional HE, which could detonate internally?
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Old 05-21-2009, 04:03 PM   #13
SuedodeuS
 
Join Date: Sep 2008
Default Re: Explosive Bullets

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Originally Posted by Ulzgoroth View Post
Ultratech stats small-arms (or relatively-small arms) HEAT (and HEDP) as doing imp damage, if I recall.
Indeed it does. It also only gives them an armor divisor of (5), rather than (10). I probably should have taken a look in UT before going off on the HEAT/etc tangent.

Quote:
Originally Posted by Ulzgoroth
I have doubts about replacing the fuzing with a simple impact-ignition thing for HEAT. A HEAT warhead needs to detonate at a short standoff distance from the surface to be penetrated, which means the trigger has to be stuck out ahead of the main charge. And I don't know, but I imagine the effect might be sensitive to just how you ignite the main charge, making the assembly more complicated.
You may be onto something there. Using Ultra-Tech and waiting until TL10+ to have HEAT in small arms may be the way to go, here. UT also has stats for small(er) EFP under the TL9 SEFOP heading. It appears 15 mm (around .60 caliber) is the smallest EFP can get, unfortunately.

Quote:
Originally Posted by Ulzgoroth
But why use it there instead of conventional HE, which could detonate internally?
HESH would also detonate internally. The spread of the explosive might have some effect on how much tissue damage it does, but the round itself (prior to detonation) would also hurt the undead a bit more by functioning like a hollowpoint round (which has a damage type upgrade). Of course, HE is much easier to make and is only marginally less effective, so you'd be better off with it. HESH is going to be basically useless in small arms. Well, unless you have a really great explosive but no good method for delivering it through armor in the first place. Then the fact that HESH apparently functions as a contact explosion could be a great boon.
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Old 05-21-2009, 04:49 PM   #14
ed_209a
 
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Join Date: Sep 2004
Default Re: Explosive Bullets

I just noticed something odd in UT.

The default smallarm ammunition at TL10 is a jacketed slug, not too different from today. An APDS round costs 5x as much as a FMJ to make.

Shaped charge rounds are only twice as expensive as a FMJ (UT155)?

Does that seem funny to anyone else? I would think that any kind of HEAT round would be much more complex to manufacture than any sabot round. No matter what your industrial base is, more complex always costs more than less complex.
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