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Everything posted by A_Mysterious_Stranger

  1. Ran across this while going down another rabbit hole INTERNATIONAL WOUND BALLISTICS ASSOCIATION - downloadable PDFs Not entirely sure if anyone has seen these or already has them, but I thought I'd bring it up just in case.
  2. Haven't really had time to dig into stuff or post (I'm sure I have stuff somewhere, its just a mess of bookmarks currently since I've had computer issues and I haven't been motivated enough to organize.) But I did run across a couple articles that might be interesting: The Failure of a Tungsten Carbide - Cobalt Cored Projectile Penetrating a Hard Target What's interesting is that this is one of those lengthier papers that has an overview of AP stuff and some background, so someone interested in learning a bit about this might find it useful even if the focus is primarily ceramics and WC. Anyhow the abstract: Optimisation of small arms defeat via dynamic jacket removal This one is another lengthy paper but it also has a small overview a newcomer to the topic might like. Bonus points for adding the Nanosuit from Crysis as an example of 'future' development. Also the influence (good or bad) of the jacket on penetration is something I've been interested in since discovering that Athena AP round. Edit: This second paper has some oddities if not inaccuracies in it so I'm not 100% sure how reliable it is, I suppose someone more qualified will have to judge that. Be warned to take anything in this with a grain of salt. The link leads to a page where you can download the paper. Abstract: Hopefully somebody will find one or both of these useful.
  3. Does anyone know for sure how much better Triple Hardness armor was supposed to be over Dual-Hardness Armor or RHAr? Janes' Technology of Tanks and Hazell's book put DHA as being equal to 1.7-1.8 it's own thickness in RHA, but aside from uncited numbers posted on various forums I haven't seen anything definite. Also this company apparently has been working with Dual-hardness steel: https://diamondage.org/advanced-alloys/ Not sure they've put anything out (or how much faith to put in their claims) but it at least seems interesting.
  4. I think it would depend on how you think lasers work. Maybe with a heat ray (to borrow Luke Campbell's term) but a pulse laser might be another matter since that stuff can be closer to shaped charges and APFSDS. I don't think CotDE go for pulse lasers though. And yeah, when scifi fans get pedantic about how it 'must' work, it gets less fun.
  5. Sloping apparently is also effective against laser weapons according to some. That is 'Hard Sci Fi Realism' (tm).
  6. I don't know if anyone ever checks the internet archive but they have books. All kinds of books. Including gun books. Understanding Firearm Ballistics https://archive.org/details/understandingfir0000rink The Thermodynamics of Firearms. Design of firearms as heat engines and the interior and exterior ballistics of projectiles. (two copies) https://archive.org/details/dli.ernet.6268 https://archive.org/details/dli.ernet.234005 The Big Book of Ballistics https://archive.org/details/BigBookOfBallisticsPhilipMassaro/page/n25/mode/2up They also have some older books that might interest some: Principles Of Firearms [ Charles Edward Balleisen And some DTIC stuff - alot of it actually: DTIC ADA226267: Superconducting and Computational Penetration Mechanics DTIC ADA570804: Physical Mechanisms of Soft Tissue Injury from Penetrating Ballistic Impact So the real treasure may be the fact there's more stuff people can find (and download, they have multiple formats and even torrents it seems) and store for technical discussion. (Also I see some of my links are down. I'll have to find some time in the future to replace them all but if somebody wants something I posted before send me a private message and I'll try to fix it.
  7. CotDE seems to be intensely enamored of armor sloping: http://www.projectrho.com/public_html/rocket/spacewardefense.php#armortheory [quote] Sloped armor: deflects projectiles instead of absorbing them—an incredibly important and obvious tactic. Also, increases the effective thickness by the secant of the angle. Space warships should have long, thin nosecones. The primary battle tactic is flanking, to get a better attack angle. This is best accomplished by spreading out groups during attacks, since it is impossible for defenders to face in multiple directions at once. [/quote] I'm not actually sure thats how it works, since I'm pretty sure modern APFSDS isn't stopped by slope unless its really extreme. And Jane's Technology of Tanks says slope won't do anything against a shaped charge jet: [quote] To increase the effectiveness of armour and in particular of the frontal armour, the original, vertical arrangement of nose, superstructure and turret plates was generally abandoned during the Second World War in favour of sloped armour. When well sloped, that is inclined at more than about 65° from the vertical, armour offered the advantage of causing some projectiles to ricochet, or to shatter, and of being able to avoid being perforated even when relatively thin. Very highly sloped armour has also degraded the performance of some shaped charge war- heads by interfering with the symmetry of the collapse of their liners into jets. Sloping of armour to a lesser degree also makes it more effective against most kinetic energy projectiles, because this causes it to offer resistance to penetration which is non-symmetrical and, therefore, deflects projectiles from going straight through the armour into a longer path. However, the advantages of sloping armour are small, if any, when it is inclined at less than 10 or 20 degrees from the vertical (15.5). This and the general effectiveness of sloped armour is illustrated in Fig. 15.4 in terms of the ratio of its effective or equivalent thickness to the actual shot-line thickness and the angle of inclination from the vertical. In contrast, sloping of the armour makes generally no difference to the penetra- tion of it by the jets of shaped charge warheads, except for the interference in some cases with the formation of the jet mentioned previously. There is therefore little to be gained by it in their case. This is true even though the sloped armour can be less thick for protection against a particular size of shaped charge, because the thick- ness in the path of the jet has to be the same whether the armour is sloped or not. Consequently, its weight per unit of the vertical area to be protected does not vary with the slope of the armour. The long-rod penetrators of APFSDS projectiles are similarly unaffected by the slope of the armour. [/quote] Kind of hard to imagine it would be ineffective against shaped charges and APFSDS, yet somehow be super effective against hypervelocity impacts.
  8. I don't think you're going to get a neat, single answer for all of this. Penetration is very complicated even when you focus only on rigid OR eroding regimes. APFSDS occupy a transitional region between those two, meaning it is likely to be even more complex. For example I did more digging by changing search parameters. One thing I turned up came from army-guide and this interesting point: Completely unsourced but it shows a the potential for multiple factors at work. I've found sources that allude to nose shape influencing interface defeat, transitions from rigid to eroding penetration and velocity thresholds, and so on. I'll share the various things I ran across in the hopes it will prove useful. In no particular order: CTH hydrocode predictions on the effect of rod nose-shape on the velocity at which tungsten alloy rods transition from rigid body to eroding penetrators when impacting thick aluminium targets Abstract: Design of hard-target penetrator nose geometry in the presence of high-speed, velocity-dependent friction, including the effects of mass loss and blunting Abstract INTERIOR AND TERMINAL BALLISTICS OF 25g LONG ROD PENETRATORS Introduction: Investigation of Oblique Penetration I: The Effects of Penetrator Leading End Shapes on Unyawed and Yawed Impacts Abstract TERMINAL BALLISTICS TEST AND ANALYSIS GUIDELINES FOR THE PENETRATION MECHANICS BRANCH Introduction: Penetration of 6061-T6511 aluminum targets by ogive-nosed VAR 4340 steel projectiles at oblique angles: experiments and simulations Abstract The Effect of Nose Shape in Long Rod Penetration (link to free PDF download) Abstract: This one seems related to the one below, so I included it more for completion's sake and informative purposes. Comparative Study of Nose Profile Role in Long-Rod Penetration Abstract: Honestly I'm not sure this is very relevant. It seems more about eroding-penetrator processes and mushrooming vs non-mushrooming. But it's also about EM guns specifically, so it was worth mentioning. Interface Defeat of Long-Rod Projectiles by Ceramic Armor Abstract: This is mostly about interface defeat in general vs ceramics, but there is a bit in there about nose shape. So nose shape may be a factor here. Interface defeat studies of long-rod projectile impacting on ceramic targets Abstract: Analysis of the Noneroding Penetration of Tungsten Alloy Long Rods Into Aluminum Targets Abstract This one seems to be more about rigid penetration, but its also about about LRPs. Worth noting for that 'transitional' aspect I mentioned and the fact nose shape has a huge impact in rigid penetration. Modeling Threshold Velocity of Hemispherical and Ogival-Nose Tungsten-Alloy Penetrators Perforating Finite Aluminum Targets Abstract
  9. What I could find: Jacketed Long-Rod Penetrators: Problems and Perspectives Though that is about Jacketed Penetrators, it seems it may still apply to regular APFSDS. Given it cites Rosenberg and Deckel you might look at their work 'Terminal Ballistics' for more information. Possibly more useful is this: The Effect of Nose Shape on Depleted Uranium (DU) Long-Rod Penetrators I apologize for not quoting any of this, but its a 66 page non searchable PDF, and I'm not sure that you can just select parts without reading the whole thing for context since it's specifically about LRP and nose shape for DU rounds (some tungsten is mentioned.) Also of possible interest are these reddit posts. I'm not sure how 'good' it is since we're talking War Thunder (I'm as wary of that as I am of WoT based research) but I figure I'd include it for completeness sake and potential for discussion: APFSDS the Science of Ricochets How tip shapes affect APFSDS performance on sloped armour I also believe that most APFSDS don't operate fully in the eroding (hydrodynamic) regime and would slow down on impact anyhow. So rigid penetration effects may apply (nose shape does matter quite a bit there). Lastly because it may be of interest to someone materials which may be of interest but may not be relevant to the discussion: Penetrator strength effect in long-rod critical ricochet angle Interaction between High-velocity Penetrators and Moving Armour Components PENETRATION OF METALLIC PLATES BY KINETIC ENERGY PROJECTILES The Relation Between Initial Yaw and Long Rod Projectile Shape after Penetrating an Oblique Thin Plate
  10. Documents pertaining to firearms ballistics, but especially terminal and wound ballistics mostly: Handbook of Firearms and Ballistics Terminal Ballistics a Text and Atlas of Gunshot Wounds Gunshot Wounds Practical Aspects of Firearms Ballistics 2nd ed. Ballistics for Physicians Myths About Wound Ballistics and Gunshot Injuries
  11. Other books for download, which I'm behind on a promise to post: THEORY OF THE INTERIOR BALLISTICS OF GUNS.J.CORNER PHD Modern Exterior Ballistics Ceramic Armor Materials By Design Lightweight ballistic composites for military and law enforcement applications
  12. Posting more stuff I find on the internet that may be of interest: THE THEORY OF HIGH SPEED GUNS Abstract In other words really fast guns that aren't railguns. INTERIOR BALLISTICS OF GUNS Preface Optimisation of small arms defeat via dynamic jacket removal (pdf download link) Abstract Ballistic protection efficiency of composite ceramics/metal armours Abstract Ballistic resistance of high hardness armor steels against 7.62mm armor piercing ammunition Abstract Impact dynamics of tool steel penetrators From the introduction: Perforation resistance of five different high-strength steel plates subjected to small-arms projectiles Abstract Ballistic behavior of high hardness perforated armor plates against 7.62 mm armor piercing projectile Abstract The Mechanical Metallurgy of Armour Steels Abstract
  13. Oh sure. That's also why it's like a wiki: as a starting point for research it's great because it can consolidate alot of information into an easy-to-access place. It's just the time needed to sift through it to determine how much of it may or may not be accurate that can be problematic. Some of the info can be a bit dated tho. Some of the Schilling stuff the energy sidearms page you linked to uses is also decades old Usenet posts lol. If you're interested in more of Luke's recent stuff you should look up his game stuff. He improved some of his ideas from the Laser Death Ray site: here's his home page you can access Vergeworlds and his GURPS house rules there. As an attempt to be more informative I'll also post some info for the Solid State Heat Capacity Laser. It's still CW I believe as opposed to pulse lasers (repetitive or otherwise) but it's interesting because it seems to be the closest we've gotten so far to a true 'Luke Campbell' style laser (It's close to his newer 'pulse laser' idea though, which you'll find mentioned on his Vergeworlds/GURPs rules) https://lasers.llnl.gov/science/photon-science/directed-energy/sshcl https://e-reports-ext.llnl.gov/pdf/245418.pdf https://e-reports-ext.llnl.gov/pdf/241387.pdf https://www.researchgate.net/publication/244988141_Solid-State_Laser_High-Energy_Laser https://str.llnl.gov/str/April06/pdfs/04_06.2.pdf
  14. Yeah, I thought about Atomic Rockets but was unsure if that would be okay to post. It's a good site but it's like a wiki. It's a dumping ground for diverse opinions culled from across the internet with little or no peer review. So you have to take it with a grain of salt. The arguments about what qualifies as 'realistic' science fiction suffer from the same problem of trying to predict the future of warfare: We suck at reading future with accuracy, and many people color the matter with their preconceived ideas. If we mention AR, I can mention Luke Campbell's 'How to Build a Laser Death Ray' site. He's one of the most prolific guys on laser weapons (including laser small arms). Much of the work has been for personal (game-related) reasons, but it's been very interesting to read his work and I consider him to be as good as the sources I linked to above because of the depth of research he's done.
  15. So, yeah. I wasn't sure where to put this but @Sturgeon was kind enough to suggest it go in the Ballistics Science forum (months ago, I've been busy with stuff) so this is where it sits. It's not exactly 'ballistics' per se, but its still science-related and relevant and interesting because it's really, really hard to find some good technical documents that isn't science fiction nerd speculation. You can actually find a surprising amount of that stuff on dtic, and I've always had a fascination since I was a kid with the old SDI program (borrowed tons of library books about lasers and particle beams too.) There are, however, a couple really good ones I've discovered, although both are really old. There are lots of other more specialized and 'misc' documents on dtic which I may or may not post in the future depending on time or interest. The first (and more recent) is a book called 'The Effects of Directed Energy Weapons' by Philip E. Nielsen: The Effects of Directed Energy Weapons Oddly it still seems to be in circulation according to Amazon (odd given its up for free on DTIC) which makes you wonder how legit that is but.. eh. The other one is much older (80s, meaning its SDI era) but it's also interesting and detailed because it originated with an AP study group on DEWs as part of the larger SDI effort I believe. And it's quite interesting because it shares similar ideas with EDEW above: Report to the American Physical Soceity of the study group on science and technology of directed energy weapons. So yeah, the biggest and best sources for such I've run across. If I find any more (or if anyone else finds them) they can post them here too in preparation for World War 3 or the Martian Invasion. The last one is more laser-focused, but still about DEWs (it's actually the source that lead me to my second source) and also comes from DTIC: Directed Energy Weapons on the Battlefield: A New Vision for 2025
  16. Some random recoil impulse figures. This stuff is interesting/important if you want to deal with guns from the back end rather than the front end, I find. Fire out of Battery Test results - a discussion of soft recoil/Fire Out of Battery recoil mitigation technologies (In the quest to put bigger guns on lighter frames) It provides a number of Ogorkiewicz ratio figures for various armored vehicles (ratio of tank gun recoil impulse to its mass. Rule of thumb is 900 ns/ton as I recall) Here is the list of 105mm 120mm and the Sheridan's 152mm gun: https://imgur.com/a/MtAyVok Designer's Dilemma - recoil, what to do with it? Covers towed/field artillery rater than sPG: 155mm towed gun figures: https://imgur.com/a/7bCBkzm Also a bit on FCS and tank guns, it includes a few interesting tidbits like recoil force and energy comparisons between 120mm and 140mm guns: DOD: DEVELOPING SCIENCE AND TECHNOLOGIES LIST SECTION 9: GROUND COMBAT SYSTEMS TECHNOLOGY It's about 15 years old by now, but its still interesting.
  17. Here are a couple intresting documents. They represent the preoccupation of one guy named Andre Gsponer with future nuclear weapons. What (to me) sets him apart is a vision of compact nuclear weapons - he terms 'fourth generation' in the 1-100 ton yield that fit a niche between existing 'conventional' and tactical/strategic (higher yield) nuclear weapons. I also like Gsponer because he rivals Friedwart Winterberg for obsession in using super explosives to set off nuclear reactions. Fourth Generation Nuclear Weapons: Military effectiveness and collateral effects The physical principles of thermonuclear explosives, inertial confinement fusion, and the quest for fourth generation nuclear weapons This one has an online version if you dislike PDFs. No abstract but I've summarized the first few sentances covering many of the chapters
  18. I know @LostCosmonaut had a thread about radiation thresholds and others have mentioned Nukemap, but I did run across this which may be of interest during one of my attempts to indulge my obsession with 50s era atomic army silliness (Blame Fallout): Casualty Estimation for Nuclear and Radiological Weapons The focus seems mostly on possible terrorist devices, but it mentions tactical stuff too. It goes without saying it's very NATO centric as well.
  19. Damn, I'll need to re-learn new nomenclature just to sound clever about body armor and terminal ballistics. Still, I'll be interested in seeing what comes of this.
  20. Well it's UHMWPE so I don't think it's subject to plugging the way a steel plate would be. It's also a lead core rather than something harder which I think affects penetration.. Also there's ballistic limit - stopping a single round of a single type/weight at a given velocity is great, but how repeatable is that fact? Can it stop such a round 50% of the time (v50) or almost every time (V0)? There's also the backface deformation (hard to judge but at least 25-30mm?). And a 4lb plate hit by a 750 grain round moving at 2400 fps is going to impart considerable energy and momentum to the body which isn't likely to be any kinder (ESPECIALLY with the aforementioned backface deformation.) Reminds me of some of the claims you used to hear about Dragon Skin. There was a similar 'test' done for something called Kryon Terminator some years back which also claimed to stop .50 cal (though it was unclear whether that had any relevance to body armor.) It's entirely possible, but with body armor there's always more to it than 'can it stop X round' (again Dragon Skin.)
  21. huh I've always meant to post something in this thread but never got around to it. Anyhow, to start I've read that one simple way to visualize how a railgun would work is the Jacob's Ladder: https://www.youtube.com/watch?v=bKD1wsBOo2M Kinda silly I know, but I couldn't resist. Howstuffworks has an explanation as well that I thought was good and may be useful for others: https://science.howstuffworks.com/rail-gun.htm Obviously the armature is a crucial component to railguns (I think of it as combining propellant and sabot though I'm not sure how accurate that is.). But like a sabot, it represents parasitic mass that you want to minimize and other factors. There are approximately four kinds of armatures I am aware of: solid, hybrid, transitioning, and plasma each with their own tradeoffs. A good description of Armatures can be found here along with the impact of various armatures on railgun performance: Efficiency Scaling for Railgun Armatures
  22. Been delayed with stuff but I've wanted to post this. Actually I'm surprised I've never seen anything in detail about this before, because it's an interesting topic. (IF there IS a topic on this I apologize and it can be merged there.) ETC tech is something you probably hear about if you hang out on tank, military or gun forums. Especially if Railguns or coilguns are mentioned. Or 'next step' in gun design like 140-152mm guns. There's lots of information out there if you look and you discover just how diverse it can be. I'm sure most people are aware that Wikipedia has a article on ETC tech and as far as Wiki articles go it's decent. But the person who worked on it in the past also wrote an article on ETC for the Nationstates draft room. It's old but still good. So despite the origins it's still useful (the writer was also a member on Tanknet IIRC. Take that as you will.) In Jane's Technology of Tanks, Ogorkiewicz also commented about ETC: Ogorkiewicz also discusses the concept in Tanks: 100 years of evolution: One realization from this is ET/ETC technology is quite diverse and can be confusing. One of the better sources covering that concerned Rheinmetall research into a German 120-140mm (courtesy of Wayback because the original source fell to link rot): Link to image of Rheinmetall ETC classifcations On the amateur experime which discusses ET/ETC stuff in detail too. If you prefer the more 'hype' side of things, ETC was also tied to the Future Combat Systems - a link some people may recognize: As you can see, ETC is evolutionary not revolutionary like EM guns. It takes existing technology and builds on it: You can settle for improving propellant ignition (minimizing electrical cost) or add electricity to boost performance (up to the 'pure' ETC idea) You can also utilize the technology on Liquid propellant and possibly even Light Gas guns - it stacks quite nicely with other ideas. You can even use it with a bigger caliber. This is part of the ETC charm. Further information on ETC stuff can be found here: AN END-TO-END MODEL OF AN ELECTROTHERMAL CHEMICAL GUN Electro-Thermal Chemical Gun Technology Study Both of these are articles I like, but there's more stuff: Electrothermal-Chemical (ETC) Technology Weaponization Issues Electrothermal-Chemical Gun Systems Utilizing Novel Electric Solid Propellants And of course DTIC is a wealth of ETC stuff: (direct pdf links): Overview on the German R&D Programs on ETC Gun Technologies for Main Battletank Weaponization ELECTROTHERMAL-CHEMICAL PROPULSION AND PERFORMANCE LIMITS FOR THE 120-MM, M256 CANNON And some dtic links to ETC stuff that requires download: Electrothermal-Chemical (ETC) Propulsion with High Loading Density Charges. Ballistic Analysis of Electrothermal-Chemical (ETC) Propellant. Trade-Offs in Performance Enhancement of Solid-Propellant (SP) Electrothermal-Chemical Guns. Sturgeon's House user sevich also posted a link to a useful ETC document off ditc here
  23. Well there's different kinds of suspension that have evolved since WW1 and they offer different tradeoffs (although some have been superseded) such as cost, simplicity/reliability, effectiveness, etc. but I also think there may be an element of semantics to it (how people define such things, which is where the sources you use and quality of that source) probably applies. Also there's going to be more issues than just 'speed' to consider in your suspension choice. For example on page 319 of Jane's: It would seem tradeoffs and design (complexity, protection, weight, internal space) are drivers over 'good' or 'bad' decisions as how it is implemented (possibly getting back to the 'semantics' again?) Speed will matter too since that affects comfort/safety/stability of the crew and vehicle vibration and such matters as Collimatrix described (the better a suspension can cancel out the bouncing/shaking of rough terrain, the faster you could in theory go.) but it's still going to be about tradeoffs in the end (including speed.) Also, the suspension itself is just part of a larger system (Wheels for example, which is also discussed in Janes) which can also play a role and probably shouldn't be ignored. Differences in engineering and metallurgy (especially over time) probably affect things too. Sorry if that isn't answering what you're specifically asking I'm trying to guess at it from your words and where in Janes you're alluding (unless you mean the Damping section?) Edit (again after many): Maybe this is what you're referring to from 13.4 in Jane's? https://imgur.com/a/Et56F
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