11-14-2019, 09:41 PM | #41 | |
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Join Date: Oct 2007
Location: Indianapolis, IN
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Re: Some TL8-9 weapon ideas & stats
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We don't check on those things. I need to play around with the knockback rules and decide if the exoskeleton and powered armor suits' strengths apply. Some of the real world testing of artillery effectiveness appeared in a article titled "Who says dumb artillery rounds can't kill armor?" https://sill-www.army.mil/firesbulle...LL_EDITION.pdf They are using larger 155mm rounds but it is all HE not SCW submunitions. A number of the pics show what near misses can do with 'near' being under 30 meters. There is a STANAG standard for what threat level a vehicle is rated for and some of that involves testing for fragment damage from shells. There is a standard for the simulator of those fragments - a 20mm round with a special blunted projectile doing 960 m/s from 25 meters 24,791J. So there is some numbers to compare fragmentation damage with.
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Joseph Paul |
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11-15-2019, 06:29 AM | #42 |
Join Date: Aug 2004
Location: Wellington, NZ
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Re: Some TL8-9 weapon ideas & stats
The real problem with the fragmentation rules is not the damage fragments do. It's that the effective reach of warheads doesn't change with size - they all throw the same number of fragments, effectively.
As the rules for fragments treat them as being an automatic weapon with skill-15 and Rcl 3, every doubling of the number of fragments should give a +1 to hit. As the damage of KE attack (bullets, etc.) scales roughly with the square root of energy, and the total energy that goes into the fragments should, all else being equal, scale with the mass of the shell, it would seem that the number of fragments scales with the cube root of mass, and thus linearly with shell diameter. So, every doubling of shell diameter is +1 to hit for fragments. A case can also be made for each doubling of fragment number (and thus density doubling the range at which a target would get hit, in which case the bonus to hit should follow the range/speed table (this implies that rapid fire should too, which some people have floated in the past). The next question is what should the baseline shell diameter be, and how should rounding be done? This is really asking where the break-points for smallish explosive rounds should land. I'd be inclined to give 30mm +1, making 15mm +0 as there's not a lot that going to be smaller than that. It also puts 20-25mm grenades and cannon in the same group and 30mm as clearly larger, which is how it tends to play out with real weapons. The next step is 60mm+ (+2), which includes just about all mortars, UT hand grenades and man-portable missiles, light artillery, and so on. Then we've got 120mm+ (+3 - at this point if you'd have been hit anyway you get hit an extra time), 240mm+ (+4), and so on - serious artillery, large rockets and missiles, bombs etc.
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Rupert Boleyn "A pessimist is an optimist with a sense of history." |
11-15-2019, 06:44 AM | #43 |
Join Date: Nov 2019
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Re: Some TL8-9 weapon ideas & stats
I'm not if such a warhead would work, but many layers of pre-made fragments surel y would be... more fragments, that in one outer case. Invention claims, that they should fly faster due to more efficent use of expanding gases, but here I became unsure.
http://www.freepatent.ru/patents/2476813 |
11-15-2019, 07:13 AM | #44 | |
Join Date: Aug 2004
Location: Wellington, NZ
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Re: Some TL8-9 weapon ideas & stats
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It'd be quite reasonable to decide your 120mm mortar shells don't need to do [6d] fragment damage, and design them to instead do [3d] with +2 to hit (and using my suggested rules above, an additional +2 for being 120mm+ in diameter), giving them a lot more reach on average.
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Rupert Boleyn "A pessimist is an optimist with a sense of history." |
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11-15-2019, 07:23 AM | #45 |
Join Date: Nov 2019
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Re: Some TL8-9 weapon ideas & stats
Also, here.
https://ndiastorage.blob.core.usgovc...069Shipley.pdf Here we speaking about our corrent 40mm grenades. While I still think that weigth and material of fragments are more on damage side, warhead shape and overall number of fragments really shoukd contribute to hit probability. |
11-15-2019, 10:30 AM | #46 | |||||||||||
Join Date: Jul 2018
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Re: Some TL8-9 weapon ideas & stats
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Volume constraints for a given round are often a big problem for add-on effects, which is why it seems 7.62 incndiary/explosive rounds are rare and specializd (yes I know about things like B-Patrone and there is at least one Russian API. I also know there's been alot of argument about them on various gun/miltech forums because of the volume issue, hence the rarity.) Quote:
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That said the concept itself (regardless of the specific approach) seems sound. Patents for a dual layer SC go back to the 60s and I found one other theoretical approach. So if your definition of realism includes 'its possible' this is entirely viable (with handwaving I suspect) even if currently known methods may have issues. On the other hand this might be a concept that would work better with something like MAHEM too given timing/reliability issues. Quote:
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Remember not to forget about tradeoffs in equipment choices. You probably can't have everything (at least not without some hefty handwaving.) Quote:
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11-15-2019, 11:02 AM | #47 | |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: Some TL8-9 weapon ideas & stats
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11-15-2019, 11:10 AM | #48 | ||||
Join Date: Nov 2019
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Re: Some TL8-9 weapon ideas & stats
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Also, tests were made with RM slughs with about 6-7grams of weight. http://book.sarov.ru/wp-content/uplo...dej-2017-1.pdf So I think that .338 would work, especially if it can pass as strictly anti-materiel round, not violating Saint Petersburg Declaration. ) Quote:
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11-15-2019, 11:52 AM | #49 |
Join Date: Jun 2013
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Re: Some TL8-9 weapon ideas & stats
To be fair, REF 25 (if accurate) gives us room to play around some. If HEDM requires 4x its weight in container (or whatever) to keep it at metastable pressure, that still gives you something like REF 5 (if 10g of HEDM requires 40g of container but is equivalent to 250g of TNT, that means 50g of HEDM+container is equivalent to 250g of TNT, for REF 5). Spaceships seems to assume the "scaffolding" necessary to keep HEDM stable is negligible in weight (or is jettisoned as the HEDM is used up).
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GURPS Overhaul |
11-15-2019, 12:33 PM | #50 |
Join Date: Feb 2016
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Re: Some TL8-9 weapon ideas & stats
The performance in Spaceships is pretty close to the 216 MJ/kg of metallic hydrogen (I think I calculated it at 75%-80%), so the scaffolding becomes part of the reaction mass (the temperature would vaporize anything used as scaffolding).
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