Bows and bullets vs Sand Bags
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- เผยแพร่เมื่อ 1 ต.ค. 2024
- Years ago I met a girl who lived in Sarajevo during the siege and she told me that they were using bows as well as assault rifles on the front lines as they shot through sand bags and water butts when bullets didn't - I needed to find out for myself; do arrows do things bullets can't?
I looked at this quickly in an earlier film but guns are tricky here in Europe, so Curt at the the VSO Gun Channel offered to do the firearms side in one film in the US and I did the arrows side over here in the UK and we spliced the films together; but with our own versions - two for the price of one!
Check out the very cool VSO film here • Arrows are Better than...
Please also excuse my 'village idiot' look for the links into Curts film - I have no idea what happened and I see no reason any of you have to mention it!
The Lockdown Longbow series of films uses a crossbow that shoots medieval weight arrows at the same speeds as a 160lbs English War Longbow and allows me to run a series of trials against armour and all things medieval longbow related. The first film in the series starts here • CRAZY idea... War bow ...
If you would like to help support the channel please visit my sites
todcutler.com for excellent budget historical weapons
todsworkshop.com for custom historical work
and for T shirts and merch please visit todsworkshop.c...
Hey everyone. It was great to work on this project and I am very happy to see it come to fruition.
Now shoot an arrow from a shotgun at the sandbag.
Very interesting results thanks for the experiment!
This dude's channel is full of bigoted commenters encouraging violence and promoting ridiculous conspiracy theories. What a great community he's cultivated!
@@michaelb5476 I'd be more interested in a slug of similar mass to the arrows - a good way to find out how much the longer arrow that won't tumble improves penetration, and how much is just the differing momentum/inertias for similar kinetic energy.
Hey you William, listen, sort your own life out, you have too much time on your hands, get a job, find a partner, stop being a single minded simp, your welcome for the advice
Does not hurt to mention the psychological effect as well. Penetration is good to note, but even with a lighter arrow, if I were a soldier in a foxhole and saw arrows start penetrating the sandbags, I would be much less comfy and more likely to change my location. I would not be inclined to determine if it could penetrate my skin. Losing one's safe position can be devastating mentally. There is a lot of value in that even without causing physical wounds.
If all going your way in a modern war are bullets and arrows and the issue are just sand bags, you are lucky because that can be easily remedied.
I still think of the Ukraine conflict where in essence every location suspected of housing soldiers was simply bombed to hell by artillery. And that was two sides using pretty conventional means, but still fighting an asymmetric conflict on a low intensity level.
I do not dare imagine what level of fire power would have been put on every square meter of assigned targets by actual first rate powers in a full blown war.
The question of bullets vs. arrows is frivolous to how wars are actually waged. The Yugoslav war was so nasty because it was a civil war where 90% of it were terror campaigns against civilian populations by either side to displace or kill unarmed civilians.
The siege of Saravejo was an absurd event in military terms... but the goal of it was not a military victory
Brilliant point 👏🏻👏🏻👏🏻
I would take it personally at this point.
@@mangalores-x_x ...you are right...
There is stories from the Balkans war if you search opposition soldiers of the Serbian lived in fear of getting a broadheads more than a bullet.
Fascinating experiment Tod, lots of ideas for post apocalyptic scenarios too. I shall mention this video to a few writer friends, it might get them thinking.
This Medieval community is awesome, big fan of your channel as well Jason!
Thanks Jason, interesting results and comparison I thought
I concur! Would make for more interesting and realistic scenarios involving crossbows for TWD or other Post-Apocalyptic Film/Series 👍
Hey when is your next video out?
It's simple physics. Against an incompressible medium, high velocity is a projectile's worst enemy. It doesn't allow the medium to flow out of the way quickly enough. What you need is something slow enough that this won't happen, but with enough mass that it will keep going.
When penetrating through a relatively dense medium, you need cross-sectional density. That is what arrows have and bullets lack.
Late response but as someone that shoots myself, if you shoot a 9mm into a gallon jug of water it will explode the jug due to it dumping all it's energy in one instant and doing massive damage which is what you want. If I bullet goes through someone they can literally just keep walking. You need that internal damage to stop a perpetrator.
My guess is that penetration (assuming fixed cross sectional area and no deformation) in sand is determined by momentum. The modern crossbow supplies nearly equal energy to the longbow and modern arrows, but the much heavier arrow penetrates much further. This would imply that the arrow is in some sort of viscous drag regime in the targets. This could be verified by finding how many bags are required to stop an arrow vs momentum/cross sectional area or by getting a sideways slow motion shot (and examining the kinematics of the arrow).
If you press sand so much due to impact, the grains will go very close to each other and form a sort of wall, if you go softer on them they will have time to be moved away. Edit: thought, not sure of it.
The velocity of bullets work against their effect on the sand and actually destroys the round because in quickly compresses the medium in front of it. Like a wall as mentioned above. The slower arrows/bolt actually plow through the medium. With the arrival of gun powder fortifications moved from stone and wood to packed and ramped earth for these reasons. I never expected to see the arrow/bolts do so well but it all makes sense now. A better test for both the arrows and bullets would be a few actual sand bags laying flat and stacked as used to fortify a position. I would stop bullets even better and might offer a challenge to the arrows. I believe a standard sandbag is about 12 inches wide so not sure how that compares to the thickness of the bags used.
it's not only the momentum (which is still 2x greater in a .308 compared to a 200 lbs crossbow), it's the hydrodynamics … water or sand particles move out of the way at typical arrow speeds (45 - 100 m/s) but cannot do so at supersonic speeds. Same reason why a slower moving bullet of same cross section and similar weight will penetrate deeper, see 7.62x39 vs. .308
My dad fought in the Korean war and when I was about twelve he took me out and showed me the same thing. He had seen bows and arrows on the northern Korean side and of course all he had was a 30-06 Garland. His point was that modern technology isn't everything and to never discount ancient technology. He's the reason I'm a blacksmith who makes flintlock rifles and fowlers and sometimes pistols.
Wow how did you get into blacksmithing? I’m fascinated by traditional metal work even if it’s just horseshoes and nails (making weapons would be cool though).
That's a beautiful story; thank you for sharing!
@@OpiatesAndTits Most towns/areas have some sort of museum/ historical site that is willing to take volunteers. That's how I got started, even a weekend a month or a couple of weekdays a month is enough; volunteers willing to learn old trades and skills are ALWAYS wanted.
All Wars are Fake so I doubt that your claims have any basis in fact.
If I was given a free hand to design a projectile for this job then it would in general be longer heavier and lower velocity. Using 55gr 5.56 is daft this is short and fast.
I am betting that the sand is similar to how water is to bullets. The higher speed bullets hit it and the sand acts more like a solid than a loose composite. Water causes high velocity bullets to shatter (as per Mythbusters) So, the sand becomes a non-newtonian liquid, where force causes it to act as a solid.
I d guess so as well. The lower speed of the havier arrow might just give the sand more time to "flow" out of the way, and the higher momentum keeps it going
That is precisely what's happening which also allows bullets to actually do what they are designed to, expand to transfer more energy, which ofc decreases penetration once they hit a target. Arrows, being slower and having more mass, don't face the same problem.
True for the faster bullets, but even the 9mm has much more energy than the arrow and was stopped unscathed.
Speed just doesn't do that much for penetration when the limitation is drag
@@markusb7804 Add in that the arrow is shaped and hardened so it maintains shape, and it won't deform like the lead bullet. Even the copper on did a bit.
@@markusb7804 I think the same :D
builders sand is coarse and locks together under pressure and that's why it's used in construction. What's happening here is similar to slowly pushing your flattened hand into sand (the arrow) and forming a fist and punching the sand (the bullet).
Thx for the explanation, makes sense
Yes, and there is not much preasure from the top. So there isn't that much friction to slow down the arrow.
Next video: which bullets can pierce an arrow stopping fabric. May be as well a good test for all the target archers which have to deal with different arrow weight, speed and tip shapes.
similar thing happens when you shoot powerful rifle at water, the bullet basically desintegrates on impact, yet from a handgun it at least goes a couple meters in
Adding a bit onto this, sand (at least wet sand) is a shear thickening fluid.
That means the viscosity increases with an increase in shear rate.
At low shear rates (deformation over time), such as a low speed impact, it exhibits a low viscosity, so less resistance to deformation.
At high shear rates, like a gunshot, the viscosity is higher, meaning more resistance to deformation, stopping the bullet.
@@kilianortmann9979 I would also be guessing that the material of the projectile plays a minor part here. Bullets (at least the ones used here) are made from softer metals such as lead, copper or lead / copper alloys. Bullets of this will spread the impact over more area whilst deforming, transferring more of its energy to the actual target. Arrows, bolts etc are made with penetration in mind. I'd be curious to see if the results are different with any type of armour-piercing bullets (and I would be guessing it might be).
Sorry mate... you can't stop the internet from talking about the cat that made an unexpected guest appearance in your video.
I thought I was the only one that noticed.
Todd Catler?
It's in Cat Heaven now.
We had a five year old boy wonder between the butts and the shooting line. He came from right to left, fortunately there was a left handed archer at that the end of line so was able she him and raise the alarm and stop the shooting. The number of time people just wondered onto the shooting field despite the signs was amazing.
@@justskip4595 Tab Cutler.
There are stories of Fred bear, of bear archery company, going around in the 1940’s and 50’s doing demonstrations to prove the old bow was a legitimate hunting weapon by shooting arrows through bags of sand that had stopped rifle and revolver shells.
I had an 80 lb Bear bow back in the '70s & it shot right through wild boar out to 50 yds.
Well the problem is bows and bullets kill in completely different ways. I am not going to say bows are not a legitimate hunting weapon because I have hunted with them. But comparing the two is like comparing apples and oranges. And anyone that thinks a bow is as effective as a firearm is missing a few crayons from their box if you know what I mean. I am sure Fred didn't think that though he was not an idiot. If I had a rifle or handgun that zipped right through a sandbag without transferring any energy into it I would be pissed. You don't want them to do that. You want them to expand and transfer energy.
Well, you won't demonstrate much with that.
The reason for this difference is explainable with physics.
Anything that impacts sand over a certain velocity begins to treat it like a non-Newtonian fluid.
When the energy is imparted on the water or sand, it begins to act as solid due to the electrons of its molecules repelling each other.
Nothing to do with any other material, from steel or concrete to woods or paper or also animal flash.
@@biteme263 having it dissipate al its energy is better anyway because you dont want to shoot a deer and it goes straight through and hits someones house
@@squidwardo7074I think the main problem there is that you shouldn’t be shooting at stuff standing in front of another person’s house.
So, all I need to do to be bulletproof is to walk around in my sandbag armor.
One thing I definitely did a lot in the Marines was fill sandbags. The bags are rectangular. The best way to stack a sandbag wall is to make a lattice work pattern by stacking two bags side by side with their longer sides touching and then to stack two more bags on top of them going the other way. A normal sandbag wall would have a bit more pressure pushing down from the top on the sandbag. When a sandbag wall has been in place for awhile, the sand also becomes quite hard packed. I'd be interested if there would be any differences.
I imagine there would be a big difference between a properly packed bag laid sideways and a bag of play sand sitting upright.
@@Mystprism If anything makes a difference, I'd say the material the bag is made of plays a bigger part than the way the bags are stacked. Sand is sand no matter how the container is oriented. The 'only' difference in the Wandering Wizard's Marine Sand Bag and the ones we saw here is the sack the sand is in.
I expect that wet sand would change things too, I know it does for compaction when building foundations and roads. Water MUST be used when compacting sand and other aggregates to reach full compaction.
@@Mystprism I think the only real difference is going to be by the tighter packing of the sand caused by the pressure from above.
I agree wandering wizard
"If this were a movie, there'd be harpoon guns," well, damn, I cannot fault that logic at all
Cruising sailors! Take note...
All movies "should" have harpoons. Hollywood lost its way.
Besides the overrated ones, how bow arrows in movies work, it's pretty accurate in reality and it's not fantasy
Please know damn is a curse word
@@giovanni545Damn. You’re right!
Cat 9:45
this man has a jetpack cat addiction
Came to the comments section to make sure I wasn't the only one to spot it
Cat Easton? Or perhaps Cat Todeschini or Catschini.
typical cat "WFT was that!" reaction
My cat tends to go where the arrow hits, making any attempt at shooting very stressful
I remember in my military training, we were able to see sandbags that had been in place for a while as firing rang backstops. The front were shredded, but the bullets didn't make it out the backs.
This gave us some confidence in the idea of taking cover behind a double-wall of sandbags.
They also taught us to use logs and trees as hard cover. However...
A few years later, I was at a rod and gun club with my .223 rifle (Ruger Mini-14) and we ran out of target before we ran out of rounds, so we propped up some fresh-cut logs between 10" and 16" out at 75 yards. After firing a couple of magazines, we went and checked to see if we were hitting, id the logs had tiny holes in the fronts, and the backs were hollowed out like a beaver went at them.
-
conclusions:
Logs don't stop bullets as well as sand. (or much at all)
But they do stop the HECK out of arrows.
As an American who has a healthy enjoyment of both medieval and modern weaponry, this is one of the best collaborations I've watched
18:41 “what does that mean?”
It means modern Italy needs to re-instate the Genoese crossbowmen and modern Britain needs longbowmen
Call them the De-entrenching squad. :D
I know this is a joke, but the other advantages of firearms more than make up for the fact they won't get through a sand bag imo.
@@CowCommando Not to mention the various other options above squad level for dealing with effective cover like .50/12.7mm, 14.5mm, 20/23mm, grenade launchers, rockets, recoilless weapons, artillery and aircraft.
Yes, but a clip with like, 14 longbow arrows is going to be a bit unwieldy....
@@jfan4reva I’m sure Jörg would find a way to make it work :)
I guess that lady knew what she was talking about. War does that to people, indeed.
You don't forget the ways your friends and family are killed.
I love the logic to include the harpoon gun. I wish there was a shot of how high my eyebrows raised when Todd broke that out.
I'm gonna guess all of us on that second bit.
@@adambielen8996 In some older videos he brought up at times that he used to regularly work for tv/film productions to build contraptions that do things. Might be a leftover from that time to either have a harpoon gun available if the production needed it or uh out of curiousity when he found out during those times that harpoon guns are interesting.
Edit: I think at least he used to make contraptions as well, might've always been limited to making sword/knife type props. It's honestly been too long since I watched those, had a quick peek through the backlog but none of the videos really stand out as "yea it was in that one". I could find the recent one about "Why are movie swords always wrong?" but that one seems to be about the weapons props business.
Harpoon is totally legit. If the ballistics of the penetrating the sand resembles water, then it is great choice to bring some weapon which is designed to work underwater. I bet the same results would be achieved with APS underwater rifle, but it its not something people usually own.
@asdrubale bisanzio Dammit, I had not known such a thing had ever existed. Apparently it was supeceded by the ASM-DT amphibious rifle, which shot with good efficiency both under water and in air. Why has no video game included these?
@@simonbrooke4065 I'd say because underwater gun fights are really rare in video games, most game devs generally aren't gun nerds that know about fancy special guns, and (probably the most important reason) it's better to have inaccuracy if it means better gameplay.
"I met a girl on Sarajevo" such a beautiful beginning to a sentence.
I had the strongest impression he was about to break into song.
Every start to an akkordian song in bosnia ever
Hey, keep it family friendly!!!! Joke
Master Tod, I think I know what is happening here. This is similar to how soft Kevlar armor will stop small arms rounds but not knives or other hand propelled shives. Firearms, regardless of caliber, rely on kinetic force to deliver most of their damage, which, when countered by a softer medium that absorbs energy, like sand, greatly reduce the total amount of energy ultimately delivered to the target. Arrows, are relying more on penetration delivered at the point of the arrow head that push the softer medium aside, rather than hammer it with energy, thus allowing the arrow to move through the sand while maintaining enough speed to deliver damage to a target on the other side of he the sand. Unrelated but your cat (at 9:30 in the video) didn't seem to appreciate be interrupted in the middle of his hunt! :)
Great example! Didn't you mean to say the opposite and that sand is good at absorbing the total energy? The total amount of energy delivered on the target is much closer to 100% than the arrows that have pass through. Perhaps the slower velocity of the arrows also gives the material to get out of the way and push at the side, and the supersonic projectile act's almost like a meteorite impact :D
Kevlar stops most knives.
I saw that same demo back in the late 60's at Boy Scout Camp. A lot of Scouts wasn't taking archery safety seriously and they showed us a 45 lbs long bow with arrow would penetrate a box of sand further than a .22 long.
I used to do some archery in a gymnasium that also had a football goal further down the range. One day, someone missed the target and hit the aluminium post of the goal. It made quite a sizable dent coming from a less than 30 pound compound bow.
I saw a similar demo on the show "That's Incredible" in the late 70's early 80's. I think they used a 30-06. It was a long time ago.
Yup.
Good way to refocus the attention.
I would like to see how Jörg's 260 pound Adder with the heavy steel bolds would perform against the sandbags.
Me too!
So there’s the infamous story of “Mad” Jack Churchill starting an ambush by shooting a German soldier with a long bow, in 1944. I’m now wondering if he knew his bow could go trough a sandbag defense and dispatch enemies hidden behind cover.
Which is even more remarkable as he was a POW in 1944 and by his own account his longbows were destroyed in 1940 by a lorry and he never used it in an ambush there either (his words, none else's)
In short: Quaint story, often an indication that it is plainly untrue.
He had a claymore as his officer's sidearm which he might have used in an antiquated fashion to command a charge.... but other than it being an unusual side arm that is not really weird given officers usually did something to indicate an assault somehow, he could have waved his undies for anyone would care.
@@mangalores-x_x I thinking waving ones undies to indicate a charge might be the way to go in WWIII
*1940 not '44
@@mangalores-x_x How about his use of it in ww1?
If people are charging waving underwear, you are watching a different film to a ww2 film
Ah, the difference between cover and concealment. One sandbag is only concealment and should never be considered to be cover. 3 sandbags are considered the min ideal and the standard for a defensive position as it can protect against a light machine gun (though supply, etc. leads some to go with 2 deep). Now if you can get that bolt through 3 bags you are beating out standard doctrine for a light machine gun.
This was a very interesting collab! Thank you Tod and also Curt for this experiment! I believe Curt got it right about the bullet being designed to break abruptly after hitting the target. The projectile brakes apart on impact and that gives the intended result, because now each little bit has less momentum. At greater velocities, much more considerable the breaking (like what happens with Whipple shields protecting spacecraft against debris flying at 7.7 km/s, for example). The arrow being slower conserves its momentum without breaking and keeps going through the sand.
Cheers!
Thank you for mentioning Whipple shields. I am going to go learn more about them. 😀
Advanced happy Christmas to all 😍 love from India
Merry Christmas to you and love from the US
@@erggml1887 Thank you brother We love you
Merry Xmas and a good new year to you from Scotland UK.
Merry Christmas friend. God Bless you and your family in 2021 🤓
And a belated ‘Happy Divali’ thank you
Very interesting to see when the arrow broke and then the head penetrated to the depth it did. During the Battle of Shrewsbury in 1403, the young Prince Hal (later, Henry V) was wounded by an arrow to his face, believed to be a deflected shot. This shows how much energy was left in that deflected shot, and how deeply it went into Hal's face (as attested to by John Bradmore's account of his treatment of him)
God, I wish I had so many crossbows just collecting dust in my shed. Btw it seems that you are gambling your camera life again
Indeed, somebody get Tod some decent longer lenses so the cameras can be safely out of harms way while focused at what we want to see!
I was going to suggest he get a plate of glass to place in front of the camera... But this means we then need a new series "Arrows vs. Glass" to see how thick the glass needs to be to stop/deflect an arrow.
@@AllanMacMillan I can't see any downsides in that
That camera is sure to dine in Valhalla one day. He used what looked to me to be an old riot shield to protect it in one video (I'm not sure if it was, it just resembled one).
@@Miki112xD You're right, no downsides at all. I've got a crossbow I built, and I'm actually thinking of trying it out against glass now because I'm curious. Mine is no lockdown longbow though, it's an inefficient leaf spring bow with no compound, only ~42 Joules. Tod's compound bow fires those medieval arrows with over 100 Joules (perhaps 120?) I can't recall the figure, it was discussed in an earlier video though.
I think if the glass were angled, it would still break but may stand a chance of deflecting the arrow.
I remember vaguely when bullet proof vests (early kevlar, etc) had to be adapted to stop knives, etc. This suggests to me that arrows (and most slow moving steel) and bullets don't share as many ballistic similarities as you'd expect.
My question is do the archery butts stop bullets? If they stop arrows but NOT bullets, then that's odd.
I don't think that archery mats are good at stopping bullets. They are designed to let the tip pass, and decelerate the arrow by putting friction on the long shafts, decelerating them slowly. Bullets are stopped by giving them something that deforms the bullet, making it absorb the energy and mushroom to further increase resistance. You would not want your arrows to bent and mushroom out.
@@paulweiterer6630 Yeah bullets stop because they dump their energy very quickly into a target, that's why they stop so quick through water or sandbags, while arrows stop more slowly
It's amazing to think that my 50 pound bow has more peniration in sand than my 308 rifle. 🙇
Crossbows have been used in modern warfare in limited numbers. Especially during WWII. Back then suppressors were not that efficient and crossbows are easier to design such that they work in any environment be it a muddy jungle, a desert, or the arctic...
Even more recently they have been used against suicide bombers as they are less likely to detonate the explosives.
All in all, they lack the hydrodynamic shock, but make sizable wounds and can have comparable stopping power to a 45 ACP FMJ
During my hunter's education course here in Ontario, Canada, we learned a little bit about this. Keep in mind that this was almost 18 years ago, so I may have forgotten details. What we were taught is that arrows basically stab through their targets, cutting through the target and retaining as much of their kinetic energy as possible, delivering more of a slicing wound. On the other hand, bullets- by design as I understand it, transfer the kinetic energy into basically a punch that pulverizes what's in it's path through concussive force.
That's as good as an explanation can get in two sentences.
That sounds incredibly wrong. Hollow points are designed to dump energy, sure, standard bullet design for the calibers in question are designed for penetration. That sounds like some fudd science to me. The likely explanation is that sand acts like water, higher the velocity the more it resists. A slow moving projectile that still has enough mass will penetrate more readily, as the 7.62X39 did. Arrows are high mass and slow moving. An arrow isn't cutting through the sand any more than you are poking through it with your finger.
@@LaughingMan44 like I said, this was 18 years ago, so I may have remembered it wrong, or they may have taught it wrong, I'm just putting it out there for discussion.
@@LaughingMan44 Penetrating a target can't be the sole purpose of a bullet, it also have to deal significant damage to it, and that is achieved by dispersing the force of the small (compared to a target) diameter of the bullet over a bigger area.
If penetration was so important why not making APDS rounds like you find on tanks?
And it's obvious that the force is immensely dispersed, seeing the difference between entry and exit holes.
@@LaughingMan44 i think that was meant by the person that told him. but i believe wat your saying is correct indeed. bullet has not enough time to push sand appart, so it acts like concrete. arrow is slower, and "cuts" (moves slow enough to push sand appart) and goes trough
Now I am kinda curious how well bullets do against archery targets
Im guessing its going to zip through no problem. Bullets go through a surprising ammount of wood
@@ravener96 oh I know, but will one target stop something like a .22lr? Or will 2 do it.
True. Each weapon is better in certain situations. Firearms are better in a dominately significant measure of situations than arrows. But this shows an outlier which is neato
@asdrubale bisanzio I know that. I just mean that I am curious to see the effects on video
@@shepardpolska Same. Seems like a good experiment to me, if Tod can get a gun (or get his target to someone with a gun).
I would imagine arrow work in a similar manner to knives when used to stab. A regular soft bulletproof vest that can stop a 44 magnum is vulnerable to being stabbed through by a regular knife. The reason for this is that bullets get caught in the fibers & dump all their energy very quickly where knives have a much longer energy transfer and also spread & ultimately cut the fibers in the bulletproof vest. With arrows being so long and also the shaft constantly flexing it has time to move the sand before dumping all its energy so it still has energy after it exists the sandbag.
Yes which is why there are separate knife and bulletproof vests.
I am guessing that there are no modern vests for protection from arrows. You need to go back to a medieval chest plate.
@@Kheldul Plate carrier vests (obviously with said plates in them) would provide protection from arrows.
Yup. A fleshy body is going to have a bad time if a bullet gets lodged in it and dumps all it's energy. All that sand spilling out the bottom would be your shredded organs, heh. Whereas an arrow might pass through and do less damage to the surrounding tissue / organs.
If there's some sort of barrier though (especially sand!), obv arrows are the way to go to still do SOME damage at least. I wonder how wood would fare? I presume bullets would do better, or about the same?
Its more due to the thinness of the knife, with the tip being being able to start to slip through the fibers and then cut through the strands...soft vests work basically like a tightly woven net, the fibers are strong in that they stretch a little and wont break, the larger surface area of pistol bullets prevent them from piercing through the fibers, its why the pointy (Spitzer) rifle style bullets will pierce through fibers in soft armor. (Also why some pistol rounds like the 5.7 which are spitzer shaped can go through soft armor)
As an American who enjoys guns, I am extremely impressed with the power of bows! Love your videos Todd!
@@TheJimyyy Every single bullet he fired with the exception of the 22lr and 45-70 was FMJ, and even the 22 was very similar to a FMJ being a copper plated round nose. The 45-70 being solid copper had more penetration than an FMJ would
@@TheJimyyy FMJ will be far better than anything lead or anything designed for expansion - but that's academic here because deformation isn't the issue here, sand is just weird stuff where high velocity impacts are concerned, seemingly becoming (proportional) more resistant the higher the velocity...
to make a point, arrows are designed to pierce and cut, like a sword. Bullets are blunt and operate on concussive force, more like a hammer. How, while a hammer isn't going to penetrate through a helmet, taking a bec de corbin to the dome will kill you easier than taking a sword thrust to the helmet. The fact bullets punch holes in things is because it's a LOT of concussive force.
If you could stop the bullets tumbling on impact they would perform better in sand .
It’s the same affect as shooting water with a bullet and arrow
This scenario reminded us of the book b y Desmond Bagley “In High Places” in which a party of survivors of a plane crash in the Andes craft a crossbow from materials at hand to hold off “the bad guys”.
In the hands of a retired school marm it proves more effective than the firearms available to their opposition.
@Tod’s Workshop Great video - full of interesting comment about the relative effectiveness of the weapons’ projectiles
@The VSO Gun Channel - Thank you for your assistance.
I feel like people would have known about this back in the day and therefore never opted for sandbags until bullets came along
In other words.. use Wood vs Arrows, and Sand vs Bullets.
@@NefariousKoel Make a sandbag out of wood, stand behind it and you literally cannot die.
So.. a sandbox. With Logs and sand between them.
@@NefariousKoel That sounds like a reinforced palisade
This is a great comparison, and shows ingenuity in combat. "You're using a bow?!?" "It works. You want me to stop?" "Carry on, soldier."
Pretty sure there was a WW2 soldier that went through the trenches with a bow.
edit: Jack Churchill, give him a look up ;)
Now imagine you're on a battlefield, and the two soldiers on either side of you die. One from a bullet wound to the head, the other still has an arrow sticking out of his skull.
Which will freak you out more?
@@MrMartinSchou Which was why "Mad Jack" used a longbow, as the signal to start the ambush.
Although capturing 42 soldiers at swordpoint basically one at a time suggests also that that was effective
Never underestimate the childlike fear governments and empires have of looking silly, same reason they spend money on tanks and ships they wish they had in WW2 instead of bizarre yet practical concepts like miniaturized assault drones...
The artillery and airborne officers look confused... "You still think war is about you?"
Mad Jack is cited because out of tens of millions of soldiers mowing each other down (actually usually getting mowed down by artillery, bombs and machine guns) he was this one guy surviving despite his antics... actually his weapon choice supports that it was not the main relevance in combat.
9:27 kitten!!!!!
It's sad that a nation famous for it's marksmenship throughout all of history are banned from owning current firearms. Those who abandon essential liberty for temporary safety deserve neither. Where I live they banned crossbows, heck, paint a kids water pistol black and you're looking at 8-20 years prison. We need to take back our rights.
Every government after watching this video “yeah. We’re gonna have to ban bows now.”
In some European countries you need a license to own a cross bow, it's shocking
Exactly what Germany has on plan now ...
I moved to Poland in 2019 and over HERE i can CARRY my LOADED Colts ANYWHERE excluding in public transportation ..
God damn i feel so happy leaving communist Germany forever.
"Ban sand as well!"
@@stiannobelisto573 crossbows are more weapon-like. To use a properly dangerous bow (100+ lbs) its typically years of practice, which suggests you're at the very least competent, knowledgable and experienced so youre less likely to be irresponsible with it.
With crossbows, any dick and tom can buy one and shoot a bolt at high draw weights. Even if its not done maliciously, any accidents due to ignorance are way more devastating. so i think different licencing for crossbow/guns/bows makes sense.
@@stiannobelisto573 lmao i made one when i was 14
Tod is shooting things, Christmas did come early this year
This demonstration is a perfect example why tank shells use arrow shaped projectiles to pierce through armor. They went back to the arrow design because it works
Tungstan penetrators are far harder than lead or copper jacketed lead common in bullets.
@@2bingtim this is true but arrow shaped projectile with fins is still basically an arrow
I believe some of that may be due to some tanks using smooth bores vs rifled. And some using a sabot round.
@@Atownforevilones Both smooth bore and rifled can shoot APFSDS rounds (arrow round I mentioned) Sabot is the round I mentioned too
@@Atownforevilones they didn't used to be smooth bore. They moved to that to take advantage of sabot rounds more easily if I'm correct.
When calculating the penetration of a hypersonic projectile through a medium with relatively low strength, one can use a rule of thumb:
The projectile will roughly displace its mass before stopping. The penetration is calculated by multiplying the length of the projectile with the density and dividing by the density of the medium.
Since the speed of sound in sand is on the order of 50-150 m/s, the bullets are hypersonic, while the arrows are close to the speed of sound.
This makes it possible for the sand to react to the arrows and move out of the way, while it is just pushed forward by the bullet.
This can be compared to a bullet vs. micrometeorite hitting water, which has a speed of sound similar to the speed of the bullet.
The bullet can move further than the rule of thumb would predict, while the micrometeorite would not, despite it having a lot more energy.
TL:DR It's about the length of the projectile and speed of sound in the medium.
another name for this property is Newton's law of collisions. he proves that for any perfectly inelastic collision, where the target and the projectile end up at the same speed, that the projectile will displace it's mass of the target before stopping because at that point the velocities of the target and the projectile will be equal.
@@matthewcallahan7209 Exactly.
Since I wasn't sure on the exact name I didn't mention it.
I knew it was Newton, but I didn't know the name of the law.
Arrows are well below the speed of sound, c40-120mph. Much pointier than bullets & far harder heads.
@@2bingtim Yes, they are much slower than speed of sound in air. But the speed of sound in sand is slower at 100 to 300 mph.
As a longbow shooter and 2A enthusiast from Texas, thank you for this video. It was wonderful, and should you be looking back on this comment section nearly 2 years later; Please ignore those haters that seem to desire to hurt you because of something relatively out of your control. People like William T. Sherman (a funny name given the politics of the actual man) and htomerif should be ignored as they bring nothing of value to the conversation.
Again thank you, and please don't let the opinions of the few silence the education of the many.
Thanks and glad you enjoyed it
Anything that impacts water or sand over a certain velocity begins to treat it like a non-Newtonian fluid.
When the energy is imparted on the water or sand, it begins to act as solid due to the electrons of its molecules repelling each other.
It is a very interesting phenomenon.
Obviously, the velocity and kinetic energy of the projectile (as well as its transfer) are the same as those that allow you to shatter/penetrate everything else other than water or sand, and that gives you all that stopping power.
There's a cat bouncing around on the left of the range, is it yours?
Luke Sheridan I was thinking that cat has got a pretty good life🙂
It's a Catt Easton cameo!
Brave cat to wander around when Tod is shooting.
Tod, first off love your stuff please keep up the great work.
Second i didn't realize i needed this comparison in my life, but now that it's happened its good to know.
Third thanks.
A demonstration of the difference between kinetic energy, MV^2, and Momentum MV. Both are conserved, but the effects are different.
1/2MV^2
Nope, this is purely a demonstration on projectile design, primarily sectional density
Thanks to The VSO Gun Channel for the cooperation on this really interesting video. As always damn good stuff Tod.
10:10 That's actually terrifying - the arrow might be stopped, but the head still carries on, and that in an unexpected direction...
I thought about the arrowheads whizzing off in all directions from the breastplate in the breastplate video. Definitely time to close the visors.
You getting shot with arrows is bad enough... but then the arrows start shooting you!
Heavy and slow offer more penetration, that's why in America, if your hunting in a heavy brushed area we hunt with what we call a brush gun
Not really , don't sent work quite like that
Actually it does work like that
Does it fire brushes or is it made of them? Or perhaps do you use it to hunt run-away brushes? Curious European asking.
@@MrBigCookieCrumble It's called a brush gun because the projectile is heavy and slow when with punch through brush instead of light and fast with the brush will cause the projectile to reflect off target
@@gettitnow3785 Lucky Gunner tested it and the results surprised me. 30-30 seemed to do a bit better than .223, but the 45-70 (which you would expect to be the King of Brush Guns) deflected about as much as the .223. Conclusion was, don't trust your big Brush round to blast through a stick and keep flying straight. It could turn a lung shot into a gut shot.
just as someone with a geology background I might throw in the fact that especially if you compare with tests somewhere else you might want to control some more variables like grain size or moisture content of the sand. I know you were just testing around, but it really might change the results enormously. Just think of the momentum difference of the sand the arrow has to move to pierce through
Just a quick thought, but does water, in this case, act more like glue between the sand grains (surface tension) or just fills the gaps between grains and adds to the mass that needs to be pushed away?
@@OperationDarkside interesting point, i would think the extra mass is the far stronger factor, water fills the gaps between the grains and so raises the density of the whole thing. But i would think there is some interaction between the water and the sandgrains. And the smaller the grains get the stronger this interaction should be. The watermolecule tends to act as a electromagnetic dipole in this sort of things. But a hydrogeologist might be a better person to ask in this kind of questions. But like i said, i would make an educated guess the simple problem of extra mass that has to be moved is the more immediate problem to be looked at
That's a fair comment for replicability however as a real-life approximation I don't think the army would be too worried about the exact content of the sand lying around when filling up sand-bags. I don't think there is a manual for using a specific moisture composition of sand for building cover out of sandbags. The point here is that you need to draw the line somewhere otherwise we might end up comparing sandbag efficiency using European sand vs. American sand vs. Middle-Eastern sand etc.
It actually doesn't really matter that much- bullets don't go through any density of sand or even rock of this volume, so any one the arrows can is a net gain, as we have no idea of the precise makeup of the sandbags used in the story.
As somebody who was in the military, most soldiers don't care about what kind of sand the put inside a sandbag... Nobody told me that somebody could shoot arrows at us and that we had to make our barriers arrow proof. Also, you grab what is available. You don't place an order at the sand store.
So sand is amazing vs bullets. But better hope they don't bring a bow to a gun fight!
Jack Churchill is an exact example of someone bringing a long bow to a gunfight
@@johnbeauvais3159 A short check indicates he never did as he said himself that he lost the longbows during transport so never used them.
@@mangalores-x_x aww
Hello Tod. I'm an American engineering student and I love the show. Question: did you wax any of the arrows in this video and is there an advantage to waxing modern arrows?
there is a video about greasing the shaft and how it helps penetration. no joke. worth watching :)
@@RallycrossGT lol
My dad was a champion archer and taught me this 45yrs ago. He explained that the arrow shaft provided the weight behind the head, something that the bullet lacks.
I remember reading books from the famous American archer Howard Hill. He ran penetration tests with arrows at elephant sculls and even shot and killed a sperm whale with a bow....just to see what an arrow could do.
He outshot the mexican skeet shooting champlon with a bow... shooting clay pigeons. He held the distance record, number of arrows in the air at once and probably other records too. Hill also did all the trick shooting in the old ' Robin hood' movie with Errol Flynn.... basically all the robin hood shots. I'm sure there's a wealth of knowledge about the penetration capabilities of arrows in his books.
Also i remember reading about an American paratrooper being dropped behind enemy lines with his bow in the second world war (probably to beat the sandbags) he went on to shoot german soldiers with it.
Air resistance increases exponentially with velocity. A medium with higher density like sand/water will resist even more. So even before deformation, the bullets are resisting a much higher force than the arrows per cross-sectional area. The mass of the object has no relationship to the resistance, so higher mass of the projectile increases penetration without increasing the force they have to fight to penetrate.
Specifically it rises at the same rate as the kinetic energy so penetration increases only as the logarithm of the energy at this kind of drag limited scenario- poor gains and the bullet is likely to break apart at that level of deaceleration anyway
Not exponentially, but with a power of 2. This is a lot less than exponential growth, but still a very fast growth.
mass is only minor factor but shape of the projectile is the major factor
In other words, slow and heavy = more penetration through water/sand.
@@Fedorchik1536maybe mispoke- there are exponential involved- air resistance increases as a square- but so does kinetic energy, rearranging and integrating, you do indeed get that you need to exponentially more velocity to get a corresponding increase I. Penetration depth, assuming an indestructible projectile even
That cat got really confused :D
it is one of those cats that is permanently confused
@@tods_workshop Its a Schrodinger style cat and is always trying to figure out where it is.
Here’s what I believe: we know that when hitting water at a greater speed it becomes like concrete, it just have the time to be pushed aside and since water does not willingly compress you get a major power brake the more speed the more resistance…
This probably what is happening with the sand too, the faster you penetrate the more it brakes you, lower speed and large moving mass will therefore perform much better.
The slow blade penetrates the shield....
@@TheFreudgonebad A slow blade, like a sword have trouble penetrating a held shield, the shield will be pushed back stealing the momentum while a much faster arrow has proven to be very nasty there, a least at this channel; however, a shield isn’t a fluid. Frankly, I believe mythbusters proved one could walk on syrup, you just had to stamp very fast, wold be very interesting to see what that war bow simulator could do in that stuff… 😊
@@bamsebrumbamsebrumen5403 I believe the statement about the blade was a Dune referrence, where body shields do counter fast moving objects (like bullets or ragular hits with blades), but a slow moving object can pass right through and fighters train to deliver strikes in a way where they slow down just before hitting the target to bypass the shield.
Check out Military Arms Channel's vid with shooting trees with various bullets. The 5.45x39 went through better than a 5.56, a 7.62x39, and a .308 and they all have comparable velocities. My thoughts are that the length of the bullet is what matters most, though other variables are at hand too.
@@kylekenney1907 Yes, hiding behind a tree, even a big one does not work well as a shield if somebody is using a rifle, I noticed that plenty of times during the service, but we never damaged any oaks or hardwood, maybe they resist a little better but probably not by much. I believe speed pack energy according to E = mc^2 so that explains one part while bullet diameter naturally means you have less resistance.
Anyway, when MythBusters used paper phonebooks as armour, dressed a car with it, and started shooting and it actually gave some protection, well that sure got me thinking. I believe what we saw there was the fluid-effect which allowed the paper to better pickup and spread the energy, but I'm not a professor.
Let’s hop Tod have a bunch of phonebooks, and some archer curiosity, just laying around… 😊
Arrows are slow and heavy compared to bullets, I wonder if slow and heavy bullets would penetrate better than light and fast. I.e. .45 ACP goes father then 9x19 and .45-70 goes farther than 7.62 Nato
Edit: Interesting
I think the sand test and the water test might have a lot in common. When the MythBusters tested shooting bullets into the water they had similar results to the bullets with the sand bag test.
Great video. Very interesting stuff :)
Amateur weapon enthusiast in a country with strict rules so little personal experience but: As far as I'm aware most bullets deform on impact, often deliberately to maximise damage. Any bullet hitting a sandbag deforms and instantly experiences massive drag, whereas an arrowhead will retain it's integrity and maintain it's minimal cross section. I'd imagine they would've preferred armour piercing rounds in Sarajavo, but being under an international embargo they made do with bows and arrows to deal with barriers and other hard targets. Oh, and some of the arrows you shot and that penetrated deep went through the top of the bag, having to push aside a minimum amount of weight of sand. Though to be fair, the double bag shots alleviated that.
Any chance of them testing with steel tipped or steel core ammo?
Edit: And I've should've watched to the end. ;)
honestly, Armor Piercing ammunition wouldn't fair much better. usually it is constructed with a steel core, and on impact with a hard surface(i.e. armor), the core continues on with a smaller cross section as the rest of the bullet is scraped off by the hard surface(think like the steel core is an ultra hard slide hammer, the rest of the bullet is there to impart momentum). Against soft targets, such as the sand bag it should not behave too differently to the standard full metal jacket. honestly, when trying to gain maximum penetration, especially in a soft medium, velocity is your enemy, mass is your friend(contrary to many ignorant opinions). speed means there is greater impact energy, which can overcome hardness, both of the target and the round, creating very devastating entry wounds as the rounds tend to come apart on impact. also, Speed tends to denote a lighter projectile, which lacks the mass to maintain momentum as it continues to push through the target.
Was thinking the same,... so what if Tod cast some lead arrow points, and fitted those to his longbow arrows, would they deform enough to stop the arrow penetrating the bag?
Replying for the 4th god damned time because my replies keep being canceled .
Not really 100% what you said , expanding ammo is not allowed in war because you are supposed to neutralize the target not kill the target in war or blow out one of their limbs with a bullet , its banned by Geneva convention to lower unnecessary harm in wars that's not to say that it wasn't used ,in Yugoslavia both sides used it and if someone was caught with that ammo it usually didn't end well for him ,
Reason why soft point bullets and hollow points and what have you is used in hunting and self defence is because it delivers more damage to an animal for example so it doesent have to suffer for too long and stops inside the target usually , you don't want ap rounds which will transfer a lot less energy and potentially hit a by stander .
It's likely not to be much different due to bullet construction. Most rifles designed in approximately the last century use a similar Spitzer point boat tailed design. This causes the bullet to start to tumble after penetration, unless the material is hard enough to stop it immediately or to deform the round and dissipate the energy. As examples of the last two cases, a steel plate can stop a round immediately and a large enough wood block would deform it . Sand is somewhere closer to deforming the round for lead as shown, however it likely does start to tumble after impact. Most armor piercing rounds depend on a hardened penetrator that is a relatively small proportion of the mass of the bullet and would likely not go any further through sand.
@@18IMAMGODINA I never said expanding. I said deforming. 5.56 NATO was initially deemed too small and weak, but was found to deform and tumble upon impact, thus deliver enough stopping power while staying within the Geneva Convention.
Great collaboration idea!
Cat middle left ^^ 9:22
So was this why Mad Jack Churchill stormed the beaches at d day with a longbow...
Landser; " I am feeling as save as a Zurich Bank behind ze sandbags"
Mad Jack: "Eat Bodkin, Jerry!"
A Carcano 6.5x52 160grain will take that bag. It will take that backstop too. In testing they were punching 34 inches of board. A wadcutter should have been used on the 9mm as well.
I really liked Curt. Definitely have him back in the future when you can.
Hello Me Cuttler, do you plan to sell the plumbatas ?
The formula for air resistance is F = 1/2p(v^2)CA
F= Drag, p = air density, v = speed, C = drag coefficient, A = cross sectional area.
If it is similar for penetrating sand then the speed squared has a big impact on the result.
It does not take much effort to slowly push a pointy stick through sand.
I think the explanation is related to drag and velocity. Sand is similar to a fluid in behavior. In fluids the drag increases with the square of the velocity. The same energy will much faster be disipated throught friction if the projectile moved faster. A bullet with roughtly the speed of sound (let's ignore that some of the projectiles are even supersonic) 300 m/s whill have 9 times more drag/friction then a arrow with 100 m/s.
I'm guessing at the velocity of the bullets, the sand either acts like a non-Newtonian fluid or-more likely-simply doesn't have time to displace (like pushing through water with the palm of your hand vs slapping water with it).
That might explain why supersonic or near sonic rounds won't pass through even with the same amount of energy. The sand just won't have enough time to get out of the way.
I am really impressed by the results. All of those bolts/arrows went clean through the sand bad unlike bullets.
But I think one thing is missing. You should've shot a recurve bow too (If that was available to you). It would be nice to see what the result could be.
I guess the guys in the Boer War, World War I, II, etc. that used sand bags knew what they were doing.
There was one British soldier during WWII who still used a longbow. I guess he too knew what he was doing...
@@iododendron3416 Jack Churchill himself stated his bow was crushed and became unusable early in the campaign.
@@commander31able60 maybe the sandbag to bow ratio was just too great...
@@iododendron3416 no "they" are covering up the fact that bows are actually the superior weapon to firearms.
@@commander31able60 'they' wait until nobody has a bow anymore and then they strike with their bows.
09:44 cat on the left is like, what the hell was that! 😂
The cat seems to be used to that. It did not appear to be spooked.
Huh, seems she wasn't bullshitting or even exaggerating then. Interesting!
As you said Todd, humans are v ingenious during times of warfare. Someone obv joined in the battle with all they had to hand (a bow), and saw it went through, then they decided it was a good idea and started using more of them. Because they work!
The sharp, piercing head probably helped a lot, too.
I’ll leave politics out but u were misinformed when u generalized Europeans as not being able to have guns. Plenty of Europeans countries have good gun laws and allow for ownership of guns that not even the USA can.
Also isnt wet sand much better then dry sand in stoping projectiles?
Much more compactness and water creates more friction in the sand.
Keep in mind they were using different colors of sand. The water content difference likely isn't as big as it appears.
irrelevant to the experiment. they do not water sand bags, it would be a waste of an important resource. they are just shoveled full and stacked.
Tod did say that the contents of the bags was "damp", so that's a happy medium, I guess.
More future experiments to be had looking at this - and sand isn't the only granular material!
In a way this reminds me of the difference between a bullet hitting a kevlar vest vs a knife. Generally speaking the knife with stab right through a bullet resistant vest unless it's specifically made to stop them. My understanding is that is due to the knife cutting the fibers and not being deformed. My guess is the weight of the arrow and the fact that the sharp points "cut" through the sand is why they pass through. The bullet is smashing into the sand and some deform as well.
I think it's more the knife pushing the fibers aside than cutting the Kevlar.
Ever tried to cut a seatbelt with a knife? Kevlar is much tougher.
@@ScottKenny1978 I'm pretty sure it cuts the fibers at as much as anything but I think the analogy still fits here.
@@ScottKenny1978 also I have cut a seat belt or two, it wasn't that tough really.
I can see bows being useful to start an assault on a position fortified with sandbags. it would take people by surprise and they might even jump out into your line of sight.
Well, there's the whole downside of them shooting you with assault rifles at distances that significantly out range your crossbows and that the folks can foil your ingenious strategy by dropping a few thin pieces of corrugated metal around, at a notably lower cost than outfitting your army with crossbows.
@@SBBurzmali True. They don't usually build fortified bunkers without a fairly clear field of view around them. However... you could stroll up to them with a wheel barrow of sand bangs in front of you quite safely apparently. Even if they see you........too bad lol.
@@MrBottlecapBill sandbags are heavy though, i wouldn't want to be the poor sod chosen to push a barrow of sand up onto a fortified position. at best you get shot at, at worst they might think you a great landmark to calibrate their mortar shots
In tamping an explosive charge in a drilled shot hole dry sand will lock together into a single mass gripping the walls of the shot hole and retain the force until the rock gives way. Soft clay does not. The bullets were locking the sand into a single solid mass with the shock of impact. The arrows at slow speed pushed the sand out of the way as a mass of individual grains. A function of energy over time. The slow speed of the arrows expended their energy over a longer time allowing the individual grains to move separately. The high speed bullets expended their energy so fast that the individual grains could not move aside so locked into a solid with their neighbours.
Any physics specialist that can draw the correct conclusions?
Heavier projectile = harder to dissipate energy?
"All gun laws are infringement"? Um... I'm not sure full level The Purge is really the best of ideas when it comes to firearms. Some gun laws are very reasonable IMO.
Which gun laws? Lets discuss this
@@riograndedosulball248 Things like waiting periods on purchasing guns (i.e., no spontaneous purchases; cuts down on both homicide and suicide), fixing gun convention loopholes (idk what the specifics should actually be, but I argue that anything that applies to every other gun retailer should apply at a convention as well), background checks are wise in my opinion as well (again, the devil is in the details here, but some sort of vetting process should be in place). Minimum age restrictions (duh). No firing in public areas. It's hard to give specifics considering it varies so much across the country. I would like to see more education put in place like mandatory training across the board including operating, storing, and educating about firearm use (for example, how to teach your kids gun safety). I would also like for people to shift their opinions about what guns they have and what they intend to use them for, though I don't know that this needs to be mandated by a law, just a shift in the culture. For example, there are few instances when one needs a super high-powered, high-capacity weapon. Most of the time something like a revolver/bolt-action rifle, or shotgun would be perfectly adequate for the job. Again, not saying that this one should be a law, but I think if this were adopted it would help the gun conversation.
Lol I thought the same thing XD sentiment is quite common in the states tho
@@Tahoza There's not one rational/logical idea you listed aside from education. That use to be common until the anti gun nuts got their way. I'm from Canada. A prime example of how gun laws have NO positive affect.
@@SkintSNIPER262 1: "Effect" not "affect".
2: Unless you explain why something you claim is true or at least give some evidence for it I'm not going to listen to it, just so you can save your breath. 👍
Speed does little for penetration In this kind of regime where it's dominated by drag- only a logarithmic dependence. Meaning you have to double the speed to get a corresponding increase in penetration- poncelet's equation
The faster projectiles break apart/deform and thus slow down quicker than otherwise
But the 9mm did not and it is in fact several times more aerodynamic than the arrow + higher energy, and yet it failed to penetrate when the arrow did easily.
The arrow simply had higher mass per unit frontal area I.e. it was longer- it's why they shape apfsds rounds like they do
Physicist here, drag will be neglectable at that distance, the problem is in how quick the sand has to move to make place for the bullet. This effect is even more clear in water but the easy explanation is that bullets try to push away sand particles at speed comperable to speed of sound, wierd things start happening at those velocities and because sand does not compress well (as water for example), it will push back extreamly effectively, this effect becomes appereant only when the object is moving fast enough.
@@MrAljosa12 how quick the fluid has to move out of the way, is just another way of saying inertial drag- where x is position, v is velocity, and a,b,c are constant with a noneggative
v'(t)=-a*v(t)^2 (formula for inertial drag)
v'(t)/v(t)=-a*v(t) (rearranging)
Taking the antiderivative of both sides with respect to t and using logarithmic integration
log(|v(t)|)=-a*x(t) +b, now exponeting both sides
|v|=e^{-a*x +b} - the velocity decays exponentially by distance due to drag- it has a large effect
A slightly more complicated version of the above where there's cut-off s is known as poncelet's equation for penetration
@@AngDavies I dont know if this is a good way of looking at it, drag is usually connected to either viscosity and planes of fluid interactiong or tubulences, this might seem like just mooving something out of the way, but i would encurage you too luck up the mach effect (it is the cone shape behind a plane after exeeding the sound limit) immagine something similar but insted of highly compressable air highly incompressable liquid..
Waves of liquid mooving faster than speed of sound in the liquid are quite interesting phenomenon and have nothing to do with drag
@@MrAljosa12 there are indeed extra effects like shock formation/viscosity to consider...but all those are going to increase, rather than decrease the deaceleration experienced by the projectile.
My point being that the quadratic term- F=1/2C_d
ho v^2(form drag), the term caused by the energy that needs to by supplied to the grains of sand in kinetic energy to allow them to move out of the way of the passing projectile is enough on its own to cause the projectile to slow down exponentially with distance.
Even
Neglecting compressibility, shock formation, most viscosity, energy required to fracture the target etc.
lets just try to assume you are right, we have a water with
ho= 1g/cm^3, and drag coeficient C_d of 0.3, Area =1cm^2 v= 1000m/s ; sand has a density of cca 1.5 g /cm^3 the force as we enter is therefore using the equation you have written F_entry = of cca 15 000 N, and the distance of stoping the bullet should be in order of some 10s of centimerers..
Ok I must admitt this number surprises me, you might as well be quite right here..
Edit: Still my big problem is by the quadratic drag law, we basically have to introduce the turbolences and I just cannot see what would turbolence in the sand even mean, but I must admit, the numbers make sense. Maybe you could look at it as just accelerating some mass of sand at giving it some kinetic energy and thats where the v^2 is from.
Good one tho.
2:08 Old fashioned compound bow?
*Looking at my recurve bow*
Was the moisture within the sand checked, surely that would make a difference - more so with the firearms.
Thanks for a great video, Tod! Penetration depth of arrows and bullets through sand can be understood with a well-known Newton penetration formula: en.wikipedia.org/wiki/Impact_depth. According to it, arrows should go much further than bullets simply because they have much higher length-to-cross section ratio.
I guess and it is because the bullets carry way more energy than arrows, so they just desintigrate when hitting the sand. Not unlike shooting at water with a gun. Mythbusters did tests with that years ago. The more powerful the round the quicker the bulled desintigrated when hitting the water.
pretty much. but not specifically higher power, more so higher velocity.
The energy of some calibres and arrows is actually very comparable - its not just the energy, its how its got the energy - Kinetic energy increases exponentially with velocity but linearly with mass, so a slow heavy arrow can have the same energy as the fast but very light bullet. Where the inertia/momentum is just mv a linear relationship, so arrows actually have more than the bullet of the same kinetic energy.
@@sinisterthoughts2896 Velocity translates into kinetic energy though.
No, they can carry the same amount of energy and it wouldn't matter much. Maybe a bit counter intuitively, but energy is speed times mass and the mass is not as important here. It's simple the counter-force generated by friction that is much, much higher for the bullet because it's much faster (the force is the speed squared), combined with the much higher friction coefficient of sand.
Thanks for cranking out great content even over the holidays!
I don't think a bag of sand stood up like that would represent a typical sand bag bunker. The double bag is closer but again not the same. A proper bunker is built like bricks in hemp bags as I recall - two side by side and two long ways (like bricks) to tie it together. In many countries the sand would be pretty damp/wet as well which could make a difference - more dense. Would the longbow man injure someone behind that structure I wonder.
What a shame that crossbows are classified the same as firearms in Australia. Then again so are airsoft and in most states gel blasters.
Quote of the day: What does it mean? I got no idea but it was fun! Gotta love life mate
The only thing that this experiment means is that Joerg is going to make SOME money with their repeating crossbow+magazing if they sell heavier bolts hahaha
In Modern wars, old fashion weapons still have room...sadly
thing is, now i need to buy a crossbow..
Tod does sell historical crossbows, as it happens.
Keep in mind, though, that they do cost a considerable amount of time. Mine's still about 7 months away. But it'll be worth it!
What a stupid shirt he's got though. Not you Todd, you're fine
It's an accurate shirt.
Amazing! So this shows that jeorg was right momentum is important too
I'm a long time fan & sub of Tod & his projects. I love the idea to include firearms comparisons, but I disagree with US gent's choice of wearing a political t-shirt.
a great deal with bullets and sand is that the high speed bullet compresses the sand in front and around the bullet which catches into each other and build pressure angainst the compression. This creates a lot of friction, which will slow down the bullet very fast and hinders it from moving the sand eazy to the sides.
This kind of compression does not really take place with arrow because of the lower velocity, so the sand can better move out of the way instead of compacting and resisting
well thats all I know and remember, sry for the bad english
So arrows are basically APFSDS, and bullets are just regular AP shell.
No because there is no discarding sabot .
Its not even ap , its an arrow there is no analogy here
love Tod's stuff, fantastic content! the VSO fellow, not so much. not quite the most accurate statements or logic. the reason 45-70 can penetrate well is based on throwing a 400 grain or greater slug. when you swap to a copper projectile you are abandoning the weight. that said, the xtreme penetrator bullet can accel at penetration, it should have been done as a what if, not as representation of 45-70 in general.
Agreed
That’s why we use sandbags in the military for defense.
The slow blade penetrates the shield.
Fascinating that the 7.62x39 (AK round) penetrated but the 7.62x51 (.308) didn't. The same sized projectile fired at a faster speed had ostensibly less penetrative power. Although before we jump to any conclusions about this particular point we should probably test those two with a proper sample size. It could have been a difference in design of the actual bullet or just a happy accident of terminal ballistics in the way those bullets tumbled (or failed to tumble) upon impact. Either way, the main point remains the same: if you're shooting at someone behind sandbags, use a harpoon gun! ;-) Really good stuff guys!
7,62x39mm and 7,62 Nato are not the same size.
Bullet diameter is the same, but Nato round is much longer and heavier.