Hey! This is a really old video. Check out our SHOTGUN TRACER SLUG video for a real treat! kzfaq.info/get/bejne/aa5khsWX3tu4lac.html

At super sonic speeds, there's a "shield" in front of a projectile that prevents those fins from gathering any air pressure to cause a rotation. Use those same projectiles and fit them into a sabot. Fire them out of a rifled slug barrel and I guarantee you'll see the result everyone is anticipating.

Dear Tim: Your rounds tumbled because of shockwave propogation and boundary layer effect. When you have an object with a pointed nose travelling supersonic, the shockwave propegates all the way to the back of the object instead of going over its control surfaces. In this case, into your control channels. If you were to put this round into a supersonic wind tunnel, you'd see the shockwave propegate all the way to the rear, and no air at all going into the grooves. Effectively, they're almost working in a vacuum. All of the boundary layer air is going AROUND the bullet instead of into your grooves. A design like this COULD work, but you need to re-think your supersonic aerodynamics. First, you need an almost blunt, hemispherical nose. Think of how a missile on a jet fighter looks. They have rounded (not pointed) noses. That's so the pressure wave doesn't propegate back along the missile body and disrupt boundary layer flow over the control fins. So the nose needs to be shaped more like a missile, and less like a spear. Second, your channels need to be wider and the "fins" between them narrower. Again, you're trying to force supersonic air to go down a tube, when it really only wants to go around. There's too much static pressure buildup inside the channels for air to flow over the control surfaces and impart a lateral force to the round. Third, you need to create a wide opening for those channels at the front, tapering down to the nose tip. Think of a NACA duct. The fins should start narrowing as they start coming down the rounded nose curve. They should meet at a point in the dead center of the nose, forming a kind of star shape when seen from the front. This will smooth the transition of air into your channels, and help maintain some kind of laminar flow inside. It should also give a sort of ram-pressure effect, forcing air to pressurize at the nose, flow through the channels, impart some lateral force and exit into the drag pocket. Finally, you should consider boat-tailing the bottom-rear of the channels slightly, and tapering the control fins off to a rear-facing wedge. This will create a bit of diffusion as the high-pressure air exits, allowing it to cleanly enter the drag pocket without creating weird wake vortices and disrupting stability. This should reduce drag and net you greater range, accuracy and impact force. Hope all this helps. Looking forward to the MkII Turbine Round!

.50 cal: exists .70 cal: *WHO'S YOUR GOD NOW*

You need a significantly higher density in the tip of the round. It would work with a rifled barrel but not the slug. Rifling on the slug requires air to go through the slits, which it won't because of the speed of the bullet. The rifled barrel will make it spin from just the slug being dragged on the rifling

Great stuff! The machine work looks beautiful, I have no doubt with a little weight change, that thing will fly as straight as an arrow. Fun vid TAO, thanks for posting.

seems to me that the propellant gasses would force the slug to spin the wrong way out of the barrel, then as atmospheric air forces it to spin in the opposite direction, it would become unstable

You said you used a "smooth bore" , you'll need a rifled barrel if ya want this to work. Even tho the slugs have rifling you need the barrel rifling to start the rotation, the rifling on the slug's does not mean a thing if it's not rotating *before leaving the barrel.

I love American innovation and creativity.

In a smooth barrel, slug doesn't stabilize gyroscopically. The rifling on the slug isn't there to spin it. The grooves in the slug are so when the slug is making contact with the barrel the entire time and when it reaches the choke the led can compress into the gaps so it doesn't create a high pressure area. The way a rifled slug stabilizes is more like a pub dart. It has more weight up front pulling the rear while the rear end acts like a fin. Gyroscopic stability only applies to a smooth slug shot through a rifled barrel.

Shoot a recoil spring out of a 12 gauge

Another cool vid Taofledermaus! Thanks!

I like to thank you gentlemen, I really enjoy watching your video especially the high speed slow motion shots..... awesome.

4:30 "sounds like a turbine, zzuiinng..." man, that was pretty funny!

This is amazing stuff, I love it. In my experience with ballistics you don't need drag to stabilize a bullet, you just need the bulk of your weight in the front. I would consider trying a tear drop design with some one in 7 fins in the back making sure that the front of the projectile is heavier than the rear by a lot. Maybe injecting lead into the front?

Thank God for KZfaq, this channel, and working from home. You make my day better.

I think a carbide tip would add some fun. 😃 Thank you for all of your videos. I really enjoy watching the ballistics of the different rounds.

do you think that maybe the "dips" are too deep , im thinking it might make them spin too fast. they are staying on target that dont seem to be the problem, maybe make the "dips" alot more shallow and put more of them

Very cool experiment and interaction with your viewers. Kudos!

Those look like fun to make. A lot of pride put into those.

It's likely been mentioned before, but the charge from the shell is forcing air/gas through the grooves from behind. It's attempting to force the slug to twist in a rotation opposite that of the intended one. Whatever effect the air between the back of the barrel and the target has on the slug is being countered by the initial force from directly behind the slug. It should also be noted that, while effective for turbines, using air to rotate the projectile about the long axis of the slug is going to produce the highest rate of spin only at the very furthest end of the slug's flight. Rifling works because it forces the projectile to reach its maximum rotational velocity immediately out of the barrel, which is what stabilizes the round. The grooved slug has no such forces upon it as it is launched from a smooth bore.

Great video. One suggestion for the guy making these rounds: at supersonic velocities the physics of flight switch to a slight variation of fluid dynamics versus aerodynamics - which means that the projectile is now travelling in a non compressible medium. In order to maintain controlled flight there can be no "flat" surfaces towards the direction of travel. I noticed that the rounds had a small flat spot at the forward tip, if he machines them to a sharper point the rounds will likely do much better.

Just an FWY. The reason the barrel is rifled and not the bullet is because force coming from behind the bullet (propultion) Will turn it the opposite way of force stopping the bullet (wind resistance). Therefore, The bullet will likely topple through the air mid way unless there is an unknown factor.

Amazing! I subscribed!

Awesome video

lets just turn everything into a shotgun compatible projectile X'D I love this channel

Cool vid! I thought they’d fly straight too! They performed nicely even though.

I've always had a similar idea and someone finally made it. I'd never had access to the tools though since I don't have my own shop.

the 1/20 twist seems to be the most powerful. epic rounds xD

I know why they do not work. When viewed from the rear, the initial blast hits the fins so that it spins the bullet in a CCW direction. Then, when the air grabs it from the front, it hits the fins causing it to try and rotate in the CW direction. This instantly causes it to tumble. The slots are too deep, causing too much drag, and should not go all the way from front to back. They should gradually taper off in depth to the OD.

Aerodynamically speaking those things are a nightmare. It's just one big award shape with THICK rifling, that's like putting a spoiler on a Nissan juke and calling it "aerodynamic."

Very Cool stuff Guy's! I find myself playing Catch-Up; But that just gv's Me more to look forward to! Thanks for Sharing,And B Safe Guy's! ✌✌✌

Upon first look , it is a fantastic design. There will be changes no doubt , good luck in its future ! 😎🇦🇺👏

Definitely SPEND the money to get better high speed cameras. It's worth it.

It's because when the explosion happens, the bullet is rotating in a direction and when it's out of the rifle the air is forcing the bullet to rotate the other way which destabilize totally the bullet (and slow it down), the rear of the bullet needs to be solid.

Awesome informational educational video experience Y'alls

I thought of that bullet many years ago when I was watching a sniper sharpened his bullet. I had the same idea but didn't have the tools or money to start. I hate having to watch other inventors does it before me, but the good thing about it all my idea came true. it's frustrating born as an inventor with many ideas but no tool or money to start.

Anyone with a basic understanding of aerodynamics, hell, if you ever played kerbal space program, you'd know that things going super fast can't "Bite" The air very well and thus won't do what you want. They just stall.

"SHWAAZZIIING" was my favorite part

Nice video!

First thing I would do, is redesign the back end. As the round exits the barrel and the gas "catches up", it could put more force on one beveled surface than the others and tumble. The grooves are what causes this, because it alters the mass symmetry. This would likely not happen on solid rounds. You also need to keep the pressure wave during flight in mind. Fire one as a sub-sonic round and see what it does. Thanks for the content!

I'd have made the shorter in length so a good crimp could be up on the shell to cycle in a mag fed semi shotgun

You don't have enough rear pressure stop at the back of the bullet. Gas is expanding at a faster rate than the slug is traveling so it is escaping through the groves in the slug, this is causing drag on your barrel walls and over pressure at the front of your slug, that's why it tumbles when if first comes out. The rapid expansion of the gas in front of the bullet is omni-directional so there is no tip control. The reason a bullet says on target is because the pressure in front of the bullet is much lower or at ambient pressure, this allows spin to generate as air in front of the bullet tries to wrap around in inside the barrel. You are losing that to the over pressure in the front. If you used a carriage or a synthetic wad (3D thermal plastic printing could make one easily) that would generate a good enough seal if engineered right. Then they separate just like putting a satellite into orbit as they leave the muzzle... Oh and your grooves are too deep, you are going to cause turbulent flow inside those grooves. Good luck guys.

Old video but wow I had high hopes for this one. Love your videos

Awesome informational educational video experience Y'alls God Bless Ya 🙏

"turban" ITS *TURB-EYE-N

Very interesting!

ever though about changing the wading/holding cup behind the projectile to a flat disc as apposed to cup style? i have watched a heap of your vids and when i see the rifled rounds, i always wonder what impact the wad has on the aerodynamics of the slug...keep up the good work at any rate!!

I think the weight distribution in the round itself has a lot to do with tumbling. If you could some how get most of the weight forward in the round I think it would work. That's why I put the metal weight in the front of the 3D rounds.

I wonder if a different material (¿lead?) would have made a difference? Ehem, I, uh, also wonder if they were rifling your barrel...

I think the creator did a great job and already made a great deal of progress. If I could provide any input I would suggest that this new aluminum slug actually requires a modified shotgun and shell in order to properly deliver. I propose a shell that allows a closer tolerance, within the barrel, to the bullet itself. Perhaps a metal shell? Also, the groves in the slug, ment for rifling, should uniformly withdraw to and end where they meet the metal shell at the base of the bullet thus allowing a proper seal. Such a shell should mimic that of a 5.56 or other actual rifle round (Wider at the base, withdrawing to a smaller diameter at the nose of the shell). Hopefully someone can turn this suggestion into a real masterpiece. I would love to but lack the workshop to do so.

The reason why shotgun slugs tumble is likely linked to how it fires and the barrel it's using. And the weight and center of gravity of the slugs. You don't see this for regular rifles and bullets, because bullets themselves have the weight on the tip weighed towards the front. The slugs in this video is weighed in Aluminum throughout the whole shape, so there is no frontal center of gravity for the ammo to keep it's shape. The best modification is putting Lead on the Tip to give the front a much needed frontal weight.

I think the problem is that the slugs are not exiting the shoty straight.

I wonder if you could make these out of rabbit poop?

I couldn't see but is the slug sitting optimally in the encasing? Might need custom casings to improve it.

This slug is like the minie reborn, and with a vengeance!

My theory is that the slug is tumbling/key holing because it is made out of aluminum; it might be too light. Maybe led might stabilize more if you wee able to cast such a precise slug.

Those are the scariest hands ive ever seen.

Super cool!

Sort of gives you and idea of why the early projectiles were round balls huh? People were pretty smart back in those days and most of these things have already been attempted, tested and failed years ago. Now having said all that, we should never give up on trying to improve things so I give the effort two thumbs up.

with the rifling going throughout the entire bullet like that, i wonder if that has an effect on the velocity, might some gas get pushed past the bullet before it exits the barrel? cool video though

why no ballistic gel? is it expensive?

channel. have you tried matching the bore and slug, and lowering the charge?

Your passion for destruction is phenomenal. I hope you will get one of those back at ya.

When will people finally stop trying to spin a bullet from a smooth bore barrel using aerodynamics alone? It is mathematically impossible to achieve the RPM necessary without slowing down the bullet to a ridiculous degree. You don't try to apply spin to bullets fired from a smooth bore. It's unnecessary and the least efficient means for stability. You need to apply massive amounts of drag to the tail of the projectile. Also, those grooves on foster type slugs do not impart spin to the slug. They are to allow the slug to squish down through ANY choke size, so the projectile is safe in almost all guns.

just a thought.. maybe if the shells were half the size the tumbling factor might be eliminated..

Are the twists in the same direction as those in the barrel?

Kool video, nice and objective,,,

aren't rifled slugs intended to be used in rifled barrels to make them spin?

Somebody should make one that shaped like like a elongated tear drop or bowling pin, shooting the fat part first.

Professional machinist

What's that song playing in the background in the 2nd half of the video? Dig that guitar shredding

I thought you said you have some 'turban' rounds...

Oh my god, turBINE. Rhymes with MINE. Turbans are headwraps.

I wonder if putting a heavy bit at the rear to move the center of mass further back would make it more stable. I also wonder if changing the direction of the rifling would have any effect.

Was the twist that was machined into the slug going to great a spin in the same direction as the rifling in the barrel. If not maybe if cancelled out spin the barrel gave it.

Isnt rifling done into the barrel?? Not the bullet...

Сначала пороховые газы в стволе раскручивают пулю в одну сторону, а потом воздух в другую. В итоге получается херня.

I wonder if weighting the leading or trailing edge would solve the tumbling problem?

This is amazing!!!✊🏾😎 also that music sounds like Joe Satriani🤘🏾🤘🏾

U need to drill a hole in the back to make it front heavy. Design these as if they are darts

seemed like a lack of effort on creating targets. probably took a long while to make those slugs. you shot the first pieces of trash you could find.

Nice

good idea!

The problem now, is the rifling goes all the way. When the powder explodes, the gases are escaping through the rifling. What then happens, is the slug leaves the barrel, and that fraction of a second is all it takes for the gases to blow it any which a way, causing it to tumble. The amount of escaping gases will also reduce the escape velocity of the slug, so it has less punch. Try gradiating the rifling, so the slug is still a whole outer diameter, at the seated end.

Were those Hillary Clinton's hard drives?

I think having a wider back end on the round will create drag, keeping it in line with the slimmer front end.

Where do you get all these weird slugs? Can they be purchased anywhere? I load for my supermag 12GA, would like to try some experiments if I could find the parts ...

What does your KZfaq user name mean

it's not the rounds fault it's the guns fault

What’s the name of the song playing in the background?

Darrens laugh cracks me up. Reminds me of a cartoon characters laugh.

?Man, if you could increase the accuracy that would be a devastating round. It obliterated that HDD

The rifling was way too thick. To work going that fast it needs to be more subtle.

Very interesting and cool! It appears that the grooves could be too deep. It appears that the deep grooves are acting more like air foils and are grabbing the air and creating heavy drag, which seems to be inducing an extreme amount of projectile instability.

What is the rounds range for accuracy? Max.?

aluminium is just not heavy enough

Shot #1 2:10 Shot #2 2:25 Shot #3 2:44 Shot #4 2:57

I don't know why but youtube has been recommending this 6 years old video to me for months now.

Just out of curiosity, why not make the slugs the same length as normal slugs? Is there any possibility that it would improve the performance or would it be the same or worse?