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About A_Mysterious_Stranger

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  1. A_Mysterious_Stranger

    Gun Science Library

    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.
  2. 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
  3. A_Mysterious_Stranger

    Random Nuclear Stuff

    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.
  4. A_Mysterious_Stranger

    The Body Armor Thread

    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.
  5. A_Mysterious_Stranger

    50 bmg protection at 4 pounds?

    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.)
  6. A_Mysterious_Stranger


    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
  7. 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
  8. A_Mysterious_Stranger

    Help me understand tank suspension

    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
  9. A_Mysterious_Stranger

    Documents Repository: Small Arms

    It's amazing what you can find on DTIC, isn't it?
  10. A_Mysterious_Stranger

    Documents Repository: Small Arms

  11. A_Mysterious_Stranger

    Gun Science Library

  12. A_Mysterious_Stranger

    Gun Science Library

    I've noticed there is no repository for ballistic science documents the way there is for the Mechanized or the infantry forums (for example) so I decided to fix this. My first offering is dtic stuff from the past on some weird and novel ways to extend the L/D ratios of spin stabilized projectiles. I originally learned about this from someone I was having a discussion with years back and hunting lead me to one of those discussions about bringing back the battleships on navweaps discussion boards where one of the posters (Zenmastur) laid out his master plan for Battleship resurrection. Which included the aforementioned 'higher than 6:1 L/D ratio spin stabilized projectiles'. It took awhile to hunt down but I eventually found some of the original documents that focused on novel projectile shapes (for a large improvement) and non-conical boat tails (for a much smaller improvement) Obviously this went nowhere insofar as I am aware, and I suspect they had drawbacks nobody addressed (like most do) but it's an interesting thing to look at anyhow. Much of this is the work of one Anders S. Platou, who seems to be as prolific as the RAVEN guy. AN IMPROVED PROJECTILE BOATTAIL AN IMPROVED PROJECTILE BOATTAIL. PART II. Improving the Flight Performance of Projectiles MUZZLE-BLAST-INDUCED TRAJECTORY PERTURBATION OF NONCONICAL AND CONICAL BOATTAIL PROJECTILES THE EFFECT OF VARIOUS BOATTAIL SHAPES ON BASE PRESSURE AND OTHER AERODYNAMIC CHARACTERISTICS OF A 7-CALIBER LONG BODY OF REVOLUTION AT M = 1.70 YAWSONDE FLIGHTS OF 155MM NON-CONICAL BOATTAIL PROJECTILES AND THE 155MM M549 PROJECTILE AT TONOPAH TEST RANGE-OCTOBER 1977 YAWSONDE FLIGHTS OF 155MM NON-CONICAL BOATTAIL PROJECTILE-B CONFIGURATIONS AT TONOPAH TEST RANGE--MARCH 1978 AEROBALLISTICS OF 9ORKSCRE1 PROJECTILES (12 page document) AEROBALLISTICS OF CORKSCREW PROJECTILES (36 page document)
  13. Wow those are a gold-mine of info and not just for the tungsten carbide stuff either (there's tons there too, like penetrator images, the implied cost savings, etc.) There's also stuff in their about the dual-purpose grenades and body armor and a different (interim?) lightweight case. From the FY2018 brochure Ramlaen posted: tungsten carbide penetrator: https://imgur.com/a/mXmcY Light weight casings (10% only) https://imgur.com/a/9hE43 I'm guessing the FY2016 link is the 'before' image (with a penny for scale) and the FY2018 image is the finished product (which resemble the EPR arrowheads) I wonder if it would be possible to derive anything about the proposed round from this?
  14. So just sharing a bunch of aforementioned links that may be of interest: First batch are a series of technical reports about a Knox Engineering company cartridge design for lightweight 5.56 NATO centering around 'enhanced propellant' and 'alternative cartridge case' (basically a straight-walled design): ENHANCED PROPELLANT AND ALTERNATIVE CARTRIDGE CASE DESIGNS DEVELOPMENT OF A LIGHTWEIGHT AMMUNITION CONCEPT USING AN ALTERNATIVE CASE MATERIAL AND ENHANCED PROPELLANT They're very similar but many of the ideas seem to overlap with what we know so may be of interest even if they are over a decade old. ... Component Technology Investigations for Light Machine Gun Applications - 2005 NDIA presentation on LMG technology concerning lighter barrels and various catridge concepts (including the Knox one above, and aluminum cases.) ... Lightweight Small Arms Technologies (Formerly known as…Lightweight Machine Gun and Ammunition) - 2005 presentation on LSAT for NDIA concerning machine guns. Like alot of it more than a decade old, but the details are interesting all the same I think as far as internals and tradeoffs go. ... ALTERNATIVE CARTRIDGE CASE MATERIAL AND DESIGN This one is more about polymer case designs and the challenges. more than a decade old but may still be of interest again. ... A new machine gun - the right weapon for today's environment A General Dynamics 2012 presentation on Machine gun improvements and design and seems focused on the LWMMG concept. Warning includes at least one mention of 'Tactical Overmatch' ... LIGHTWEIGHT AMMUNITION DESIGN - 8550 - 2009 presentation by Colt on a 'hybrid' cased/caseless 'modular' design and a polymer spiral case for .50 BMG ammunition. Interesting for the 'modular' design being a 'caseless' cartridge inside a brass case with two giant holes cut in the side. ... SHOULD THE U.S. ARMY ADOPT NEW 5.56MM AMMUNITION CARTRIDGE DESIGNS TO REDUCE OVERALL AMMUNITION WEIGHT? Found this in with what I was digging through, decided to keep it anyhow since it is something Sturgeon has interest in, although he may have already seen/read it. Does cover some of the concepts mentioned above though as well (the colt modular concept, as well as aluminum, steel, polymer, telescoped, etc.)
  15. Sorry for the delay, I was digging for info after reading the replies. As usual I end up with more than needed because I find new stuff that distracts me* I think you're right on the gun pressures but I haven't bothered checking lately. I find this interesting too given that a few weeks back on TFB there was a mention of the army Looking into combustible cartridges for small arms - whether the SBIR produces anything or not it's still an interesting coincidence, especially given Sturgeon's comments below. You've got me interested, but my own mind draws a blank. Could I persuade you to elaborate? Oops, you're right. My bad. That actually sounds like a big deal if they can pull it off. With the previously mentioned insulating qualities of CT ammo you have quite a few options for propellant (something closer to tank propellant impetus for example? I think 'specific impetus' or 'force constant' are the correct terms.) and helps explain CT requiring less propellant than modern ammo (or improve performance for the same amount of propellant.) Do you know if the Carbine uses the same internal mechanisms as the light machine gun? I can recall seeing a few different ideas for CT feeding and I know Textron had a particular one it went for. You've mentioned Minisi and the Magnum round before on TFB so I can see the correlation and association with others like DocGKR. Newill is a new name but a search did turn up a few possibly interesting things like a design on small caliber ammo ballistics and a magazine article on small arms ammo design. Unless it allows fire on the move won't that impede mobility (further) and add more weight? It's also interesting given mention of the third arm project: https://www.army.mil/article/201229/army_researchers_advance_third_arm_project_to_next_testing_phase A device to allow troops to carry heavy guns and 20 lbs shields matches what the Army has been hinting at. But also makes it sound like they're partly/totally abandoning mobility in favor of range and firepower. In other news I see another update on TFB about the NGSAR with more info: http://www.thefirearmblog.com/blog/2018/03/05/us-army-calls-next-generation-squad-automatic-rifle-prototypes/ The interesting bits from the Product Opportuinty Notice as posted on TFB: That sounds like to me they are emulating the Marine's ideas with the M27, but also aren't that attached to obscene 1200m ranges either. On the other hand, didn't they try to make one rifle do everything with the M14 before? I also turned up this NDIA (I think it's the one referenced in TFB update) https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2017/armament/Beal.pdf * I'm not kidding. I actually 'rediscovered' a bunch of links I'd lost whilst digging and ended up with a ton of stuff that is only slightly relevant. I'll post it after this on the off chance it might be of interest, but if not then it can be more easily split off where it belongs if it doesn't belong here (apologies if it doesn't)