Structured barrels are a relatively recent development and interesting in and of themselves. One of the main objectives is to eliminate barrel harmonics that distort accuracy. The article didn't provide much info on the structured barrel used to break the record, so here's some from the only company I'm aware of that specializes in making them:
> traveling at a downward angle and about 600 feet per second as they reached the target zone.
That is incredible. Some BB guns don't even fire horizontally that fast
> Regarding it taking 69 shots to hit the mark, with all the variables that had to be taken into account, “we were thrilled it was so few,” Humphries said.
Just to clarify, I'm pretty sure they're saying that the bullet left the muzzle at 3,300 fps and had decelerated down to 600 fps at time of impact, not that it was moving vertically at 600 feet per second. So the fact that it was moving faster than a BB gun isn't really shocking.
Assuming the bullet is traveling on a purely ballistic trajectory, no weird aerodynamics, calculator is saying it will have a vertical delta V of -235 m/s at 24 seconds. So more like -700 ft/s. But friction is real so I don’t know the real number.
I’m quite surprised they didn’t have the barrel pointed higher. Was the shooter on a plateau?
At these ranges, wind, heat, humidity and more play huge factors into the bullet's trajectory. I highly doubt even a bench rest would yield anything resembling a group at this range.
There shouldn't be any limit to the distance of a rifle shot along a parabolic trajectory if someone builds an appropriate cannon and can shoot many times aye? Artillery shoots much further...
Is there a restriction which prevents a motivated team that can manufacture their own barrels from building a rifle/howitzer hybrid?
This record is only somewhat a record because it’s done with a rifle firing an ammunition sized for a rifle. By the standard of artillery, there is nothing remarkable here.
The criteria used here are very arbitrary. That’s why they can beat their own record by 43% years after setting it. No one is really interested in doing what they are doing because that’s not really interesting.
Is this an engineering challenge or a marksmanship challenge?
Like... Could you just fire the gun, then put the target where the bullet went an fire again and say its mission accomplished because the real goal is just setting up a gun that stable and precise and deterministic?
>Like... Could you just fire the gun, then put the target where the bullet went an fire again and say its mission accomplished because the real goal is just setting up a gun that stable and precise and deterministic?
No... slight variations in wind and atmospherics across that distance change too rapidly and significantly to make that viable. (Also, you wouldn't need to, you'd just adjust the windage/elevation on the optics and/or fancy rifle mount.)
Also the when the bullet drops from supersonic to subsonic speed, there is a non-deterministic kick that it receives which dramatically reduces accuracy beyond that distance.
>Also the when the bullet drops from supersonic to subsonic speed, there is a non-deterministic kick that it receives which dramatically reduces accuracy beyond that distance.
Fun fact, while video games typically depict suppressors as slowing bullets down, and lowering range (presumably with subsonic ammo). A lot of rifles are actually have slightly longer range with a suppressor and standard ammo because it allows the powder to burn more completely with a slightly higher muzzle velocity and therefore it takes longer to hit that subsonic transition
> No... slight variations in wind and atmospherics across that distance change too rapidly and significantly to make that viable.
This doesn't sound right. If it's true, then the same thing -- slight variations over time in wind and atmospherics across a seven kilometer span -- would make the aimed shot nonviable too. The shooter isn't adjusting for air movement between himself and the target -- because that can't be done -- so if he's hitting the target reliably, the air movement can't really matter.
ok wind aside, if that's true, how is it possible to aim it then? It can't possibly be true that you can precisely adjust your aim to hit a specific target if you can't even hit the same target by not changing your aim?
Both - the firearm has to be incredibly precise, but you also have to take into account wind and air density to get that much accuracy, and a big portion of marksmanship is accounting for those. Knowing that you'll have a temperature change over a body of water, and how to adjust for that, for example.
But I can't imagine you're dynamically adjusting each shot for these changing factors every time. You'll almost certainly be holding the aim fixed once you've figured it out to be approximately correct, and firing against natural variance in the variable conditions.
Maybe moving the target to the bullet impact would work - walk the shot to the target or the target to the shot? Both still have many other variables - but there is one good reason why they moved the shot instead of the target.
It would be very difficult to find impact points of the misses - The best they could do was listen for where they hit.
But surely that only refers to the first bundle of shots while trying to guess and check where the gun is aiming? If your ability to tell where the last shot landed was so low on the previous shot, your ability to precisely calibrate and hit a small target on the next shot must be zero.
* I am more amazed at the quality of the scope that the shooter could place a bullet on a 8" bullseye at a distance of 7.08km. There must be something fascinating to it since, Rayleigh's criterion for resolving two points puts some physical limits to the aperture. To resolve a palm sized mark, you need a sufficiently large aperture on telescope & that's not easy to mount/operate.
* This is one of the neatest images I have seen of the effect of rifling on the bullet, in addition to the thermochemical effect on the bullet tip. The tip at that distance & time of flight goes through sustained heating & there is some evidence of rapid oxidation - much like a piece of metal exposed for few seconds to blowtorch.
That looks like rusted iron residue transferred from the sheet metal backing of the target. They had a board down the middle that they had to cut away to extract the bullet so it was encased in the wood for a while with vaporized metal and water before they got it out.
I don't see where they tell us what bullet they used, but it's hinted at being a copper jacketed/bonded lead bullet.
So we're seeing copper, and black residue from barrel fouling, aka. powder residue from inside the barrel's rifling. You should be able to wash and/or tumble most of the residue off the bullet and get something shiny out of it.
I am pretty sure in this case the scope is used just like scopes on artillery. You would be interested how artillery scopes resolve from tens of kilometers? They do not.
artillery can rarely see their target. My understanding is they use a reference point they place near by and are good at turning offsets to this to the correct angle and powder charge to reach the target. it helps to have an observer that can see the target the can provide aim adjust feedback.
Note that they can do direct fire missions where the target is sighted directly. but I think that is considered too damn close when that happens.
Also note that tanks(a direct fire device) have been known to engage targets at 4+ kilometers. Probably a case of a large stable mount, and a good targeting computer.
A fun fact, computing artillery tables was the primary task of some of the first electronic computers.
Rayleigh's criterion doesn't hard limit your ability to aim-- so long as you have a good prior what the image plane projection of the target is.
To give a contrived example. Say we have a function f(x) == a*exp(-(x-m)^2). I evaluate f(x) at 1 and 2 and tell you that the evaluations are f(1)=0.27093242847450331643480903517 and f(2)=1.1666240719274935885932696286. From that, you can tell me the amplitude (a) and peak position (m) with on the order of 100 bits of precision (in this example).
This is contrived because its noiseless and you know the system response perfectly, but I think it demonstrates that an alignment under assumptions need not be limited by rayleigh's criterion.
For this kind of experiment, do you even need a scope?
(Asking as a complete noob).
It seems what you need most of all, is the ability to make the most minute of adjustments to the aim of the rifle, combined with feedback on where the last bullet landed relative to the target.
Then it becomes a bit like Newton-Raphson approximation.
Or are the conditions on the record such that each successive firing must aim from scratch?
One question of interest is how far repeated shots with the exact same rifle aim are going to land from each other. That would depend on changing wind directions and other atmospheric effects. Presumably you pick a day of near zero winds for such attempts.
Agreed, the scope is really just a rough aid in an application like this. How do you even know how to adjust the scope for that range in the first place? You’d zero in on the target by adjusting group to group, or in this case probably shot to shot.
The design of the bullet itself is interesting. Normally, longer and thinner is more aerodynamic, in any fluid, air or water - it creates less turbulence and drag. But here they found shorter and fatter works better for transonic projectiles:
> The .416 Barrett cartridge is made by “necking down” a .50 Browning Machine Gun (BMG) round to accommodate the roughly .40-caliber bullet. It’s a relatively short, stout bullet that proved ideal for its purpose, Humphries said.
> “Traditionally in extreme long-range shooting, we wanted long, skinny bullets,” he said. “However, we discovered that as a bullet crosses over into subsonic velocity, it flies better if it’s shorter and fatter.”
Bullets in flight have a few dynamical modes where they have a sort of wobble around the direction of travel. They all, when given enough distance, end up tumbling end over end which absolutely ruins accuracy though getting hit with a tumbling bullet is quite destructive for soft targets.
I can totally see trying for a record being helped with a low aspect ratio bullet (er, short and stubby) though this is probably not what you’d actually do if you were doing anything but trying for records.
Fun fact: if you don’t correct for the fact that the earth is spinning which requires knowing your latitude and compass direction, your targeting will be off by an amount measured in feet at this range.
I spent a while developing external ballistics models for a similar use case years ago.
The standard tome of knowledge is McCoy - Modern Exterior Ballistics https://a.co/d/8B6w0qL
Would you happen to know why so many high speed videos of bullets show them flying pitched up or down slightly from the direction of flight shortly after leaving the muzzle?
> “When a bullet is in flight for that long, you have to take into account the rotational speed of the earth. What you’re shooting at isn’t going to be in the same place it was 24 second ago when you pulled the trigger.”
Wow. Impressive work! I also noted the pitch differential between scope and barrel :O
Impressive, indeed [1], but its the easiest of the corrections they had to do. Its a standard classical physics question and has been included in artillery calculations since at least the late 19th century.
[1] Id imagine that a bullet, being so light compared to a shell, is more affected by fluid flow than the coreolis force. That the correction was needed means they nailed the far more difficult fluid problem.
Coriolis deflection is a rounding error compared other sources of inaccuracy. In their press release[1] they said they didn't account for it:
> Scott made the wind and elevation call of 1,092 MOA up and 17 MOA left. (In our original release, I forgot to include that we added a 36 MOA left mechanical wind adjustment at the beginning of the day for a total of 53 MOA for the hit. Our calculation for spindrift was 93.80” right) We did not take into account the Coriolis, as much of that is lost in the weeds with respect to wind (6-9 mph), temperature rising (constantly adjusting elevation) and time of flight. The bullet’s flight path is over 2500 feet above line-of-sight and there is a lot going on up there that we are unable to predictably compensate for. If it had been an absolutely dead-calm day it definitely would be one more variable to try to address.
MOA stands for minute of angle, which is 1/60th of a degree, so a 1,092 MOA adjustment is 18.2 degrees. It's insane that they managed to hit the target.
It's essentially a little bit similar to a mortar shell launch I suppose, at that distance? Reminds me of the fun I had trying to do ultra long distance shots playing Gunbound (South Korean MMMORPG that was similar to Worms) online. Very impressive.
Military snipers in training will practice at a mile+ and take the Coriolis Effect into account (or at least be trained to). Though they'll tell you the likelihood of getting one-shot one-kill is pretty low once you go past a mile of range.
This reminds me about the Ukrainian Snipex Alligator sniper rifle I read about recently. It uses 14.5-millimeter heavy machine gun rounds and it's claimed to be able to penetrate 10mm steel armor at 1,500 meters.
It's super easy to buy a gun online. The part that is not easy is getting around the step where it has to be shipped to someone or something (company) that has a federal firearms license, which then is supposed to perform the background check on you before handing over the weapon you paid for. But there's myriad websites that will happily take your credit card info and ship anything that's not NFA class 3 to the FFL of your choice.
What’s your interpretation of easy? These types of firearms aren’t cheap. For example, a Barrett .50 BMG M82A1 is like $12,000. No website is going to ship it directly to you either. It has to go through an FFL which will perform a background check.
It’s not that big of a deal really. A guy in the high power rocketry hobby club I’m in has a 20mm cannon. It’s a single shot anti tank rifle basically. It’s pretty much impossible to use it in a crime because of how gigantic and heavy it is.
You might have trouble reaching them these days since they are based out of Kharkiv and make everything in house. But you can give them a call if you want one. You might have problems taking it out of Ukraine to your home country though.
If you have nine grand available on a visa card you can buy a Barrett m82a1 online right now, ship to local FFL, fill out a form, pick it up in a week or two.
> “The bullet is coming down so slowly, and at about a 48-degree angle, it was just penetrating into the ground without kicking up dust.”
I have no shooting experience, but the arc they have to put into the shot to travel 4.4 miles (~7 km), seems so counter-intuitive to what I associate with shooting. Really impressive work by this team, to have all this calculated out so that they can hit it within 69 shots.
I'm really curious what the success rate of their shot is. From the video, it sounds like the unsuccessful shots were still relatively close by, enough that they seemed confident in being able to still guide it in, so around 1/100 sounds about right, as a crude prior estimate.
Over water (completely flat) you have a maximum sight-line of 3.1 miles due to the curve of the earth. Not only is this shot unlikely to be repeatable, but it is downright impossible without a forward observer.
The current record for the farthest sniper shot resulting in a kill is just under 2.2 miles for reference. With the power requirements to get a bullet out that far, all of the longest sniper shots are using effectively anti-material rifles (designed to take out a car engine, not a person).
“It’s a one-in-a-million shot. They said it’s not statistically repeatable,” he said. “The amount of precision and time that went into that shot was simply amazing.
Readit News
https://www.thefirearmblog.com/blog/2019/07/30/tacomhq-struc...
https://tacomhq.com/structured-barrels/
The Engineering Behind a TACOMHQ Structured Barrel: https://www.youtube.com/watch?v=C-7LKQYtU48
He done it with every iteration of the AR-15.
The last one was a WWST rifle (a moderized AR with super light materials), and the thing shot like a laser beam.
https://youtu.be/-QoQznLh29Q
> traveling at a downward angle and about 600 feet per second as they reached the target zone.
That is incredible. Some BB guns don't even fire horizontally that fast
> Regarding it taking 69 shots to hit the mark, with all the variables that had to be taken into account, “we were thrilled it was so few,” Humphries said.
To give an idea of how difficult this is....
And I'm into shooting sports.
I’m quite surprised they didn’t have the barrel pointed higher. Was the shooter on a plateau?
Is there a restriction which prevents a motivated team that can manufacture their own barrels from building a rifle/howitzer hybrid?
The criteria used here are very arbitrary. That’s why they can beat their own record by 43% years after setting it. No one is really interested in doing what they are doing because that’s not really interesting.
Like... Could you just fire the gun, then put the target where the bullet went an fire again and say its mission accomplished because the real goal is just setting up a gun that stable and precise and deterministic?
>Like... Could you just fire the gun, then put the target where the bullet went an fire again and say its mission accomplished because the real goal is just setting up a gun that stable and precise and deterministic?
No... slight variations in wind and atmospherics across that distance change too rapidly and significantly to make that viable. (Also, you wouldn't need to, you'd just adjust the windage/elevation on the optics and/or fancy rifle mount.)
Also the when the bullet drops from supersonic to subsonic speed, there is a non-deterministic kick that it receives which dramatically reduces accuracy beyond that distance.
Fun fact, while video games typically depict suppressors as slowing bullets down, and lowering range (presumably with subsonic ammo). A lot of rifles are actually have slightly longer range with a suppressor and standard ammo because it allows the powder to burn more completely with a slightly higher muzzle velocity and therefore it takes longer to hit that subsonic transition
Actually non-deterministic? Or just difficult-to-deterministic? Genuinely curious.
This doesn't sound right. If it's true, then the same thing -- slight variations over time in wind and atmospherics across a seven kilometer span -- would make the aimed shot nonviable too. The shooter isn't adjusting for air movement between himself and the target -- because that can't be done -- so if he's hitting the target reliably, the air movement can't really matter.
It would be very difficult to find impact points of the misses - The best they could do was listen for where they hit.
Deleted Comment
* I am more amazed at the quality of the scope that the shooter could place a bullet on a 8" bullseye at a distance of 7.08km. There must be something fascinating to it since, Rayleigh's criterion for resolving two points puts some physical limits to the aperture. To resolve a palm sized mark, you need a sufficiently large aperture on telescope & that's not easy to mount/operate.
* This is one of the neatest images I have seen of the effect of rifling on the bullet, in addition to the thermochemical effect on the bullet tip. The tip at that distance & time of flight goes through sustained heating & there is some evidence of rapid oxidation - much like a piece of metal exposed for few seconds to blowtorch.
EDIT, and I see now that's why they put the periscope ahead of it. That lets them dial past the scope's zeroing limits.
* https://en.wikipedia.org/wiki/Minute_and_second_of_arc#Firea...
* https://en.wikipedia.org/wiki/Milliradian
Then your post to see, oh, I have that one.
It’s good, but I’ve had better, and it’s heavy which doesn’t matter in this application.
So we're seeing copper, and black residue from barrel fouling, aka. powder residue from inside the barrel's rifling. You should be able to wash and/or tumble most of the residue off the bullet and get something shiny out of it.
For reference, most of your typical spotting scopes are 60x... and even at 1,000 yards things are hard to see.
Here's an article with helpful images through several popular spotting scopes for comparison[1].
[1] https://www.pewpewtactical.com/best-spotting-scopes/
Note that they can do direct fire missions where the target is sighted directly. but I think that is considered too damn close when that happens.
Also note that tanks(a direct fire device) have been known to engage targets at 4+ kilometers. Probably a case of a large stable mount, and a good targeting computer.
A fun fact, computing artillery tables was the primary task of some of the first electronic computers.
To give a contrived example. Say we have a function f(x) == a*exp(-(x-m)^2). I evaluate f(x) at 1 and 2 and tell you that the evaluations are f(1)=0.27093242847450331643480903517 and f(2)=1.1666240719274935885932696286. From that, you can tell me the amplitude (a) and peak position (m) with on the order of 100 bits of precision (in this example).
This is contrived because its noiseless and you know the system response perfectly, but I think it demonstrates that an alignment under assumptions need not be limited by rayleigh's criterion.
It seems what you need most of all, is the ability to make the most minute of adjustments to the aim of the rifle, combined with feedback on where the last bullet landed relative to the target. Then it becomes a bit like Newton-Raphson approximation. Or are the conditions on the record such that each successive firing must aim from scratch?
One question of interest is how far repeated shots with the exact same rifle aim are going to land from each other. That would depend on changing wind directions and other atmospheric effects. Presumably you pick a day of near zero winds for such attempts.
> The .416 Barrett cartridge is made by “necking down” a .50 Browning Machine Gun (BMG) round to accommodate the roughly .40-caliber bullet. It’s a relatively short, stout bullet that proved ideal for its purpose, Humphries said.
> “Traditionally in extreme long-range shooting, we wanted long, skinny bullets,” he said. “However, we discovered that as a bullet crosses over into subsonic velocity, it flies better if it’s shorter and fatter.”
I can totally see trying for a record being helped with a low aspect ratio bullet (er, short and stubby) though this is probably not what you’d actually do if you were doing anything but trying for records.
Fun fact: if you don’t correct for the fact that the earth is spinning which requires knowing your latitude and compass direction, your targeting will be off by an amount measured in feet at this range.
I spent a while developing external ballistics models for a similar use case years ago.
The standard tome of knowledge is McCoy - Modern Exterior Ballistics https://a.co/d/8B6w0qL
Wow. Impressive work! I also noted the pitch differential between scope and barrel :O
[1] Id imagine that a bullet, being so light compared to a shell, is more affected by fluid flow than the coreolis force. That the correction was needed means they nailed the far more difficult fluid problem.
> Scott made the wind and elevation call of 1,092 MOA up and 17 MOA left. (In our original release, I forgot to include that we added a 36 MOA left mechanical wind adjustment at the beginning of the day for a total of 53 MOA for the hit. Our calculation for spindrift was 93.80” right) We did not take into account the Coriolis, as much of that is lost in the weeds with respect to wind (6-9 mph), temperature rising (constantly adjusting elevation) and time of flight. The bullet’s flight path is over 2500 feet above line-of-sight and there is a lot going on up there that we are unable to predictably compensate for. If it had been an absolutely dead-calm day it definitely would be one more variable to try to address.
MOA stands for minute of angle, which is 1/60th of a degree, so a 1,092 MOA adjustment is 18.2 degrees. It's insane that they managed to hit the target.
1. https://nomadrifleman.com/world-record-shot/
> At this distance you'll also have to take the Coriolis effect into account.
COD did it first
https://www.popularmechanics.com/military/weapons/a41283557/...
https://snipex.com/alligator
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Headquarters: 4, 23 Serpnia Lane, Kharkiv 61103, Ukraine Tel.: +38 (057) 717-44-44. Mon.–Sat.: 9 a.m. – 7 p.m. (GMT+3) E-mail: snipex@snipex.com
I have no shooting experience, but the arc they have to put into the shot to travel 4.4 miles (~7 km), seems so counter-intuitive to what I associate with shooting. Really impressive work by this team, to have all this calculated out so that they can hit it within 69 shots.
I'm really curious what the success rate of their shot is. From the video, it sounds like the unsuccessful shots were still relatively close by, enough that they seemed confident in being able to still guide it in, so around 1/100 sounds about right, as a crude prior estimate.
The current record for the farthest sniper shot resulting in a kill is just under 2.2 miles for reference. With the power requirements to get a bullet out that far, all of the longest sniper shots are using effectively anti-material rifles (designed to take out a car engine, not a person).
“It’s a one-in-a-million shot. They said it’s not statistically repeatable,” he said. “The amount of precision and time that went into that shot was simply amazing.