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Ensign Expendable posted:Two is that HEAT jets decrease in effectiveness greatly if the projectile is spinning. There are two ways to go about correcting this, one is to make a rotating sleeve that engages with the rifling while the warhead stays still, the other is to just go smoothbore and stabilize the projectile with fins. Turns out fins are pretty good for stabilization, just as good as rifling, so kinetic penetrators also became finned. Are fins in general just as good as rifling, or are they as good once a certain amount of speed, pressure, or whatever is achieved? bewbies posted:I didn't read the quoted part first and thought this was a curiously aggressive response to a fairly benign post Same.
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Dec 24, 2020 02:20
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bewbies posted:I didn't read the quoted part first and thought this was a curiously aggressive response to a fairly benign post I mean you are going to be exactly the same way if artillery damages your hearing out the blue. And no doubt through the history of artillery transending time, culture and langauge most of those reactions have certainly followed.
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Dec 24, 2020 02:52
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Ensign Expendable posted:Two is that HEAT jets decrease in effectiveness greatly if the projectile is spinning. There are two ways to go about correcting this, one is to make a rotating sleeve that engages with the rifling while the warhead stays still, the other is to just go smoothbore and stabilize the projectile with fins. Turns out fins are pretty good for stabilization, just as good as rifling, so kinetic penetrators also became finned. Don't fins also necessitate a sub-calibre projectile? I can only assume this loss of diameter has less of a detrimental effect than the spinning would have.
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Dec 24, 2020 03:04
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The current 120mm HEAT round for the US is subcaliber.Ensign Expendable posted:Two is that HEAT jets decrease in effectiveness greatly if the projectile is spinning. There are two ways to go about correcting this, one is to make a rotating sleeve that engages with the rifling while the warhead stays still, the other is to just go smoothbore and stabilize the projectile with fins. Turns out fins are pretty good for stabilization, just as good as rifling, so kinetic penetrators also became finned. Or you're French and you go with a variation in the first and have the HEAT warhead stabilized inside of the shell that is fired
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Dec 24, 2020 03:25
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Because of the tank gun rifling/fin chat, I have probably my dumbest question ever : What'd happen if you tried to do that with like a rifle or a pistol or something? I assume there must be some trade-off which is why I've never heard of it (or I'm just ignorant) like it's easier to maintain small arms/they're cheaper or something but just from staring into space for 4 seconds and thinking about the physics I don't see any obvious problems with the change in scale. But, you know, I'm a moron. So why aren't there weird fin-bullets? (We should call them gun arrows.)
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Dec 24, 2020 03:56
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There were Gyrojets. The gun is a dumb tube with a trigger and a barrel only good enough to get the projectile going in the right direction. The projectile is a small rocket that propels and spins itself.
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Dec 24, 2020 03:59
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Xiahou Dun posted:Because of the tank gun rifling/fin chat, I have probably my dumbest question ever : There's the gyrojet gun, which uses microrockets that are spin-stabilized by having the exhaust come out at a slight angle. As I recall, it kind of worked, but was inaccurate and really expensive. On the plus side, no recoil! e:f;b
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Dec 24, 2020 04:01
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O I know about gyrojects. I specifically meant like a literally normal bullet but with fins in a smoothbore. Sorry if I was unclear. I'm assuming there's an obvious technical reason that I don't know and I'm curious. But thank you for the responses.
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Dec 24, 2020 04:03
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The tradeoffs change with the size of the projectile and the length of the barrel I believe, also when you want as much velocity as possible you want to reduce drag and friction as much as you can. Throw in the benefit of a better HEAT projectile and other options and it just becomes an easier choice. Unless you're British, then it's bad armored cav island.
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Dec 24, 2020 04:04
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The cost per round would skyrocket because this would be much more complex and fiddly than an ordinary slug. Meanwhile the performance effects would range from minimal benefit (minimally better velocity/mass ratio) to outright detriment (lose more in mass than you gain in velocity) depending on the specifics of the round.
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Dec 24, 2020 04:06
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Xiahou Dun posted:O I know about gyrojects. I specifically meant like a literally normal bullet but with fins in a smoothbore. Sorry if I was unclear. There's this weird gimmick round that someone used to try and get around US gun laws. 
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Dec 24, 2020 04:13
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GotLag posted:Don't fins also necessitate a sub-calibre projectile? I can only assume this loss of diameter has less of a detrimental effect than the spinning would have. If you have a modern-ish tank, and want to blow a hole in another modern-ish tank's armor, the loss of diameter is a good thing. The best way to make that hole is with a very fast, narrow chunk of an extremely dense metal. HEAT jets can be disrupted by reactive armor or clever composite armor designs, but a big chunk of solid kinetic energy focused into a narrow-diameter circle is hard to mess with. To make this work, modern armor-penetrating rounds are skinny darts made out of tungsten or depleted uranium. They're long and narrow so they don't lose as much velocity over distance, carry plenty of mass via their length, and concentrate all that mass onto a smaller point when they hit. They have fins to stay stabilized. To fire it out of a larger-diameter barrel, they use a sabot around the dart that falls off shortly after leaving the barrel. The design is creatively named APFSDS, for "armor-piercing, fin stabilized, discarding sabot." You could theoretically do the same thing with a very skinny 20-40mm rifled barrel, ditching the fins, but you run into a couple of issues. First off, you still want to be able to fire other types of rounds out of your tank's gun, because main battle tanks have lots of different jobs. If you're shooting at a bunker, 100ish mm of HE is much more useful than 30mm of HE. And, second, spinning the projectile means you lose some of that all-important kinetic energy (that's going into spin instead of push), and have to worry about wear on the rifling. It's easier to just make a larger barrel and use it to fire saboted darts.
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Dec 24, 2020 04:17
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The Lone Badger posted:There's this weird gimmick round that someone used to try and get around US gun laws. Someone saw the Nerf Vortex commercial with John Elway too many times.
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Dec 24, 2020 04:18
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There are some fin‐stabilised shotgun slugs, but not common, and I have to assume there’s a good reason for that. One use of fins is in stabilising rubber slugs, which makes sense because rubber bullets are fragile.The Lone Badger posted:There's this weird gimmick round that someone used to try and get around US gun laws. Yeah this was some Franklin Armory bullshit they introduced at Shotshow 2018. Didn’t work well and didn’t fool ATF.
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Dec 24, 2020 04:21
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I stood too close to a cannon when I was 12; a 16-pounder firing a quarter charge. I wanted to see it up close so I snuck under the safety rope at the last moment. Now my friends have to tap me on the shoulder before speaking to me.Platystemon posted:
What loophole was it trying to use? I've heard stories of convicted felons being allowed to possess smoothbore black powder pistols, was this playing with the definition of "smoothbore"?
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Dec 24, 2020 04:35
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Xiahou Dun posted:O I know about gyrojects. I specifically meant like a literally normal bullet but with fins in a smoothbore. Sorry if I was unclear. Finned shells exist for shotguns. Some are intended as less than lethal rounds for crowd control. And there some designed for smooth bore hunting. The ACR program had some entries that used flechettes but I believe guns firing them weren't smooth bore. I could be wrong, someone in TFR likely knows better. The issue they found from testing flechettes was that at long range they tended to be hosed by wind. HEAT rounds weigh a lot more so the wind impacts tend to be less. But it's an idea that pops up in military weapon designs periodically.
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Dec 24, 2020 04:40
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Cool, thanks for indulging my random curiosity cause I wasn't gonna go to TFR just for one question. I appreciate learning.Space Gopher posted:carry plenty of mass via their length It's a new thread and too soon to change a good title, but o come on. It's right there.
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Dec 24, 2020 04:50
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Chamale posted:What loophole was it trying to use? I've heard stories of convicted felons being allowed to possess smoothbore black powder pistols, was this playing with the definition of "smoothbore"? It took ATF two years to issue an opinion about it, and Franklin was simultaneously more and less effective at skirting regulations than many expected. quote:During this examination, FATD determined that the straight lands and grooves incorporated into the barrel design ofthe Reformation do not impart a spin onto a projectile when fired through the barrel. Consequently, the Reformation is not a "rifle" as that term is defined in the GCA and NFA. Moreover, because the Reformation is not chambered for shotgun shells, it is not a shotgun as defined in the NFA. Given these determinations, the Reformation is classified as a shotgun that is subject only to the provisions of the GCA (i.e., it is not a weapon subject to the provisions of the NFA). The key implication of this is that by not being subject to the NFA, it can be made with a short barrel without requiring a tax stamp. The catch is that because this is now the first member of a hitherto unknown class of firearm, it runs into bureaucratic inertia that’s way worse than if it were just a short‐barrelled rifle quote:1) An FFL may lawfully sell/transfer a GCA/SBS, such as the Reformation, to the holder of an appropriate FFL (a GCA/SBS cannot be transferred to the holder of a type 06 or type 03 FFL). It’s a year later now and AFAICT, there are still no mechanisms in place. Franklin was not expecting to run into these problems. Almost no one can buy their gun. So, assuming a person holds an appropriate firearms licence (basically, “is a dealer”), they could get this gun that has functional problems, they can’t sell to the public, and can’t transport across state lines, or they could go through the legal channels to get a short‐barrelled rifle, or they could get a pistol and “arm brace” that has none of these problems. But if they did that, they wouldn’t be so eminent in virtue signalling “I HATE GUN CONTROL” . Platystemon fucked around with this message at 05:07 on Dec 24, 2020 |
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Dec 24, 2020 04:53
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Chamale posted:I've heard stories of convicted felons being allowed to possess smoothbore black powder pistols, was this playing with the definition of "smoothbore"?
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Dec 24, 2020 04:56
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Chamale posted:I stood too close to a cannon when I was 12; a 16-pounder firing a quarter charge. I wanted to see it up close so I snuck under the safety rope at the last moment. Now my friends have to tap me on the shoulder before speaking to me. IIRC they were trying to make and sell an SBR (Short Barreled Rifle, i.e. a rifle with a barrel length under 16") without having to comply with US firearms laws (Which require a $200 tax stamp and background checks to purchase an SBR). InRange TV (Ian from Forgotten Weapons and his buddy Karl) had a video dunking on it a while back: https://www.youtube.com/watch?v=1hkiVc0n_Yg
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Dec 24, 2020 04:56
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Didn't the British have a sabot round they used during WWII that had some problems? What were they and how were they corrected?
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Dec 24, 2020 05:13
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Chamale posted:was this playing with the definition of "smoothbore"? You see, the straight grooves make the bore not smooth, but it’s not a rifle because the grooves do not impart spin. They successfully rules‐lawyered this bit, it’s just everything else that didn’t work out.
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Dec 24, 2020 05:17
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Watching the Pacific for first time, had two questions: -in opening narration Tom Hanks refers to Pearl Harbor as the greatest American military disaster. Assuming he’s only counting stuff up to that point, as the loss of the Philippines was much worse, would there be any argument Pearl Harbor was the worst? Off the top of my head: -Chancellorsville -Siege of Charleston -Battle of Bladensburg Also at the start of the episode in late 1941 there is a world map that for some reason has Iceland in Nazi red. Was there fear Germany was trying to seize the island?
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Dec 24, 2020 06:07
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Hyrax Attack! posted:-in opening narration Tom Hanks refers to Pearl Harbor as the greatest American military disaster. Assuming he’s only counting stuff up to that point, as the loss of the Philippines was much worse, would there be any argument Pearl Harbor was the worst? Off the top of my head: I have not heard of 2 of those 3 battles...now I'm interested in hearing about them. I would still say losing the entire capital fleet in 2 hours is the biggest one to that point invading Iraq was a bigger one IMO quote:Also at the start of the episode in late 1941 there is a world map that for some reason has Iceland in Nazi red. Was there fear Germany was trying to seize the island? I don't think the Nazi's ever actually planned for it, but Norway showed they could do all sorts of here fore impossible things already. The US technically invaded and occupied Iceland to stop any other funny business from happening. Someone should ask Drachinifel his opinion on the chance of German success.
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Dec 24, 2020 06:29
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White Coke posted:Didn't the British have a sabot round they used during WWII that had some problems? What were they and how were they corrected? The British APDS rounds suffered from the "DS" not "D"-ing properly—or to put it more plainly, the sabot would fail to separate from the penetrator in a uniform manner, which would cause the round to wobble and lose accuracy, particularly at distance. This section of this video goes into it somewhat: https://www.youtube.com/watch?v=DaE0VJ7IaFU&t=1494s
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Dec 24, 2020 07:06
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Hyrax Attack! posted:Watching the Pacific for first time, had two questions: I'm just an idiot chiming in, but depending on how you compared things through periods and who you count as "Americans" in the ACW is going to dramatically change that number at the very least Like an only-Union and we're just gonna go by what it would cost to make a cannon today in a modern factory vs. we're counting all deaths and somehow trying to account for industrial differences with space magic, are going to come up with some wildly different conclusions. (Examples not meant to be accurate to anything, just to highlight extremes to illustrate the point.)
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Dec 24, 2020 07:21
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Comstar posted:I don't think the Nazi's ever actually planned for it, but Norway showed they could do all sorts of here fore impossible things already. The US technically invaded and occupied Iceland to stop any other funny business from happening. Someone should ask Drachinifel his opinion on the chance of German success. Yeah I’m sure they had a plan drawn up but i dunno how an occupation could have been supplied assuming the Royal and American navies were still a factor.
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Dec 24, 2020 07:36
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HEY GUNS posted:i hate crossfit so no I bet no one has ever asked you to participate in a Passion Nenonen fucked around with this message at 08:57 on Dec 24, 2020 |
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Dec 24, 2020 08:55
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The Battle of Bladensburg is definitely the greatest American military disaster, since the Canadians keep claiming to have burned down the White House.
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Dec 24, 2020 09:32
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White Coke posted:The Battle of Bladensburg is definitely the greatest American military disaster, since the Canadians keep claiming to have burned down the White House. After reading the wikipedia page on it, it really seems like it needs to be filmed as a complete screwball comedy.
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Dec 24, 2020 11:03
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SeanBeansShako posted:I mean you are going to be exactly the same way if artillery damages your hearing out the blue. Where the majority of people manning artillery throughout history suffering from severe hearing problems then? I haven't heard about any form ear protection, but people must of recognised the issue and attempted to ameliorate it somehow, right? Or was the hands and mouth method enough protection?
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Dec 24, 2020 11:15
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PittTheElder posted:Those look like absolutely tiny charges, Napoleonic would probably be more smoke. Yeah, that video was the first that I found that had unlimbering with horses - the cannons are going to be using tiny charges as they've for display with random general public around. https://www.youtube.com/watch?v=cy99rH16gQk has a walkthrough of the entire process in detail. https://www.youtube.com/watch?v=H_iDWJ7gbIU has the cannon being fired from a better veiwpoint.
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Dec 24, 2020 11:18
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Vagabong posted:Where the majority of people manning artillery throughout history suffering from severe hearing problems then? I haven't heard about any form ear protection, but people must of recognised the issue and attempted to ameliorate it somehow, right? Or was the hands and mouth method enough protection? Attempts to tackle such issues with soldiering together, whether working with machinery, around machinery and of course operating weaponry only started to be seriously considered outside the small tricks of the trade in the late 20th century. My dad who was in the RAF from the eighties to the early nineties was given foam ear plugs, tiny cheap things that were barely worn. This was before PPE really got into the system. His hearing is hosed, but only partially to soldiering (he listened to music loudly and went to concerts when he could). Soldiers until recently would have suffered all kinds of hearing issues. Also, RIP Uniform History channel. You were good, but sadly you will be gone. I will wait for another. SeanBeansShako fucked around with this message at 15:22 on Dec 24, 2020 |
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Dec 24, 2020 15:19
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SeanBeansShako posted:
What happened to it? And yeah, soldiers hearing tends to get hosed even today. Hearing loss is really common.
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Dec 24, 2020 15:26
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Cyrano4747 posted:What happened to it? According to that little creator feedback window on YouTube they are just shutting it down. I guess it was just not pulling in the money for the creator and they need to work in other fields. A shame, the camo pattern/uniform stuff was great and had a blast with the fictional cosplay/recreation videos too.
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Dec 24, 2020 15:28
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small arms use uniform lead cast projectiles for the most part because you need to make billions of them, and that's the cheapest way to make them so that they fly straight. solid lead is homogeneous. there's no off-center heavy spot to make it wobble and fly wrong. sabots and darts and flechettes and their friends all need to be cast perfectly in their weird shapes and cast so that their mass is perfectly centered. arms dealers have problems doing this with bullets that have "penetrators" like the USA (NATO?) m855, which has some steel on/in it that can be off-center. imagine them making a billion 3mm fin-stabilized darts in 8mm sabots.
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Dec 24, 2020 15:38
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Greg12 posted:small arms use uniform lead cast projectiles for the most part because you need to make billions of them, and that's the cheapest way to make them so that they fly straight. This is nitpicky, but there can absolutely be problems with modern small arms round that lead to them being non-uniform in the ways that matter for flying. It's not just the homogenous nature of the lead, the round also has to be properly concentric. You can gently caress up drawing the metal jacket over the lead in a way that leaves you with a center of gravity that's sub-optimal for stable flight. You also have to make sure that nothing funky goes on in the casting process. Voids or other issues can leave you with an interior that's very much not just 100% homogenous lead all the way through, which again affects how the round balances and also the weight (more on that below). Then you have the copper jacket, which is another stage where defects can be introduced. The weight of the projectile also matters. Accuracy isn't just about stabilization, it's about being able to consistently put two rounds as close together as possible. Changing the weight of the bullet changes the ballistics, which changes the point of impact. So even if your lead pour is perfectly consistent in terms of producing a uniform interior, if you end up with slight variations in weight that can also throw things off. The end result of this is that if you're making your own ammo there is a huge difference, both in price and quality, between cheap projectiles and good ones. You can get cheap 5.56 bullets for ~$.10 each if you buy them 1000 or more at a time. The match-grade stuff is more like ~$.30 to $.50 each, depending on what exactly you're buying. And even with the good stuff the really high end shooters will weight the bullets and sort them by weight in pretty small increments. Then there are tools for measuring and adjusting the concentricity of the round etc. All of that is the kind of poo poo that no one is going to worry about if they're cranking out a few million rounds for a machine gun or infantryman's rifle, but it comes up when you get into precision shooting, whether civilian or military . edit: that's just the actual bullets. There are a ton of other things that come into play with how the cartridge is made. The seating depth of the projectile, the neck tension of the brass, how consistent the interior volume of the brass is, the quality of the primer, what kind of powder and how accurately each charge is measured, etc. Which all tl;drs down to some huge variation in ammunition quality between countries and eras. Soviet 7.62x54r loaded for MGs is pretty poo poo ammo, while Swiss 7.5mm is famous for being of insanely high quality or something that was issued to conscripts. edit 2: that's not to say the Soviets couldn't make good ammo. They just had a strong sense of what as good enough for purpose. The de-linked heavy ball you might have bought at a gun show in the early 00s was utter trash, but the 7N1 loading for marksman rifles that came in a few times was all around really good. Same deal with their rifles - a m91/30 Mosin made for infantry use could be really rough, with a sloppily reamed chamber and kinda crappy barrel etc. Good enough for minute of fascist at 100 yards, but all in all mediocre, especially when paired with that awful ammo. On the other hand a Mosin sniper rifle was made on a different line in the same factory and were of equal quality to anything you would find made in any other country at the time. Pair a sniper m91/30 with good ammo and it's a very accurate gun. Pair a general issue m91/30 with issue ammo and it's the epitome of "good enough, I guess."
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Dec 24, 2020 15:58
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SeanBeansShako posted:My dad who was in the RAF from the eighties to the early nineties was given foam ear plugs, tiny cheap things that were barely worn. This was before PPE really got into the system. His hearing is hosed, but only partially to soldiering (he listened to music loudly and went to concerts when he could). Same hearing protection + armor crew = I have hearing loss and tinnitus for life. Thanks, USMC.
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Dec 24, 2020 17:15
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Vagabong posted:Where the majority of people manning artillery throughout history suffering from severe hearing problems then? I haven't heard about any form ear protection, but people must of recognised the issue and attempted to ameliorate it somehow, right? Or was the hands and mouth method enough protection? Veterans are deaf as a category because they are constantly exposed to loud noise from a variety of sources (small arms, explosives, machinery, etc). Gunners are extremely deaf as a specific category. The hands and mouth method is not sufficient. Cessna posted:Same hearing protection + armor crew = I have hearing loss and tinnitus for life. Hell a bunch of my friends who were in tanks in foreverwar have some deafness and I know a couple of TCs who are more deaf in one ear due to the location of the main gun. It's hard to be in a giant armored machine that shoots a big gently caress off gun and not have it affect your hearing.
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Dec 24, 2020 17:25
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Would civil war cannon crews have widespread hearing loss? Im assuming yes, but not sure if they would have fired far fewer rounds with less powerful charges and if that would have mattered.
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Dec 24, 2020 19:38
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