I will make a reservation right away, the author has nothing to do with the subject of small weapons it does not have, one might say, a pacifist and Greenpeace in one person. The topic was only interested because the events more than fifty years ago on the pass now called the Dyatlov Pass, clearly spoke about the use of weapons of an unknown type there. The sum of known facts about the events at the Dyatlov Pass can only be explained by assuming that nine tourists were killed by high-speed bullets of small diameter. So an initial interest in the topic of small arms arose from the question of how to disperse a miniature arrow-shaped object with a diameter of about a millimeter to a speed of 10-20 km / s. Such characteristics should have had the bullet of this unknown weapon.
Of course, it can be assumed that some exotic technology such as railgun was used to disperse such a miniature bullet, but I think everything is much more prosaic, the same result can be obtained using conventional powder technologies available from the middle of the last century, or even earlier. These technologies were discussed in the article “The Principle of the Lemon Pits”, but the main question that remained unlit there was the initial launch of such a miniature bullet and the principle of its stabilization in flight.
Filling this gap, I will describe a real way to disperse a bullet on the basis of a well-known, but never used in artillery artillery technology, and moreover, I will demonstrate the implementation of this technology on the current layout.
Artillery classics - piston acceleration of the projectile
Since the time of the “King of Peas”, traditional rifle systems use the kinematic system piston-cylinder.
"Tsar Cannon" and the modern artillery system on the basis of their actions are completely similar.
Barrel rifle projectile acceleration technology has been used unchanged for about a thousand years and, by its kinematic essence, it is a piston (projectile) - cylinder (barrel) system. Energy to this system is transmitted through the combustion of gunpowder leading to a sharp increase in pressure on the bottom of the piston (projectile). Accordingly, the velocity of the projectile is proportional to the area of the bottom of the projectile and the pressure in the barrel; these proportions determine the limit of the velocity of acceleration of the projectile.
So, both the unicorn of the Middle Ages, and the super-modern art system are inherently the same thing, moreover, the unhurried development of technology has closed the circle, the artillery began with a smooth-bore weapon and ends its evolutionary development again in a smooth-bore version.
But evolution, after all, is not a circle, but a spiral, so the idea of an even earlier period of weapon development, the throwing dart, is used again. Rifle - from the word arrow, by the way. Here is a snapshot of what can be squeezed out of the classic barrel rifle system:
A snapshot of a real shot, a piercing projectile at the time of resetting the gage tabs. The barrel of this rifle system is not rifled, aerodynamic empennage is used to stabilize the flight of the projectile, in fact the artillerymen again began to use arrows, a bullet (projectile) such a core to call the tongue does not turn.
The speeds in 2-2,5 km / s are maximum even for such an advanced piston projectile acceleration technology, a further increase in speed rests on the limiting pressures maintained by the barrel of an artillery mount.
But at the disposal of modern civilization there is another technology for creating high-speed kinetic weapons, which came from even deeper antiquity.
Do not think that the author was "moved off mind" by posting a picture of a sailboat in an article on weapons.
A sailboat (clipper) is directly related to the topic under discussion.
Humankind has been using wind energy since time immemorial, and it can be used not only for the movement of such sea monsters, but also in artillery. After all, what is an explosion in essence?
This is VERY, VERY strong wind.
I did not discover the Americas here; this method has already been used in artillery since the middle of the last century. A cumulative explosion is used to disperse small objects (let's call them “bullets”) from the beginning of the last century, this is the so-called “shock core” technology, in cumulative ammunition.
Here’s how the aerodynamic principle of acceleration of a “bullet” looks like in practice:
This is a photo of the impact nucleus in flight, immediately after its departure from the gas cumulative jet (black cloud to the right), a trace of a shock wave (Mach cone) is visible on the surface.
We will call everything by its true names, the shock core, - this is a High-speed bullet, only accelerated not in the barrel, but in a stream of gases. And the cumulative charge itself is a Tankless artillery. Acceleration of the bullet is carried out using the Aerodynamic type of energy transfer.
But this technology is also used as a self-sufficient artillery system. An example is the development of the beginning of the 80 of the last century, the domestic anti-tank "mine" TM-83, with a lesion area of more than 50 meters. But the modern, and again the domestic sample of such a barrel-free artillery installation:
This is an anti-helicopter "mine", the range of "spitting" cumulative charge to 180 meters. The speed of its "bullet" 3km / sec, it is very far from the theoretical limit of technology in 200km / sec, but this is the inevitable price for the accuracy of aiming in such a barrelless artillery system.
From all the above, an obvious engineering solution suggests itself; it is necessary to combine the receiver technology, with its aiming accuracy and the technology of aerodynamic acceleration of the projectile with its real potential of achieving speed in 200km / sec.
Clipper in a bottle
Nowhere to escape from the marine theme, after all, sail was invented by sailors ...
If we consider the bottle as a barrel, and the mock-up of the sailboat as a bullet, we get the artillery system we need.
Well, the wind will create a powder charge between the bottom of the bottle and the sailboat ...
With a single shot from a conventional receiver rifle installation, the gas outflow rate will reach 5-7km / sec to the limit, which is no small and such a “breeze” is enough to disperse the aerodynamic bullet. It remains to place a bullet with aerodynamic surfaces (sails) inside the barrel, and the rifle unit is ready, in the limit, which can disperse the bullet to the speed of the gas jet.
To stabilize the flight of such an aerodynamic bullet and in the barrel and what is more important in the atmosphere, it is necessary to impart a rotational motion to the bullet, but not by using rifling, as well as by aerodynamic method. This can be done using not primitive "straight" sails, but more cunning, "oblique" sails, as a result, approximately this construction will be obtained:
This is a gas turbine rotor, structurally aerodynamic bullet should be approximately the same. The products of burning gunpowder, passing through the blades, will push such a bullet forward and spin around the central axis.
By the way, efficiency (efficiency) for free-flying turbines (with a non-fixed rotation axis) approaches 80 percent, and piston systems cannot convert energy with efficiency greater than 30 percent, as they say, feel the difference.
But this is not all, while moving in the barrel the aerodynamic bullet should not touch the walls of the trunk, otherwise neither the trunk nor the bullet will remain intact, it is necessary to ensure a uniform gap between the walls of the trunk and the ends of the sailing surfaces, and the smaller, the better.
This technical problem has already been solved in completely different fields of technology, the air cushion method in the aerodynamically shaped gap between two planes is already used in aviation (ekranoplanes) and in computer technology (hard drives).
The magnetic heads of the hard drive "hover" above the surface of the disk at a distance of several microns, the airbag is created by turbulent air flow from the rapidly rotating disk. For an aerodynamic bullet, microns are a brute force, there is enough clearance in a millimeter 0,1-0,2, which is much easier to provide.
In fact, the bullet will work as an aerodynamic surface, not only the plane of the “sail”, but also its end. What form it should be to ensure self-centering in the barrel channel is well known to aerodynamics.
Such a “leaky” bullet looms, and this is not a traditional lead blank, used since the “King of Peas” in almost unchanged form, it is a product of advanced achievements of at least two scientific disciplines, gas dynamics and aerodynamics.
Things are easy, it remains only to make such an aerodynamic bullet.
And "I did it ..."
Of course, I am far from the Anglicans' masters with their small-scopes, even though I am Russian, but absolutely Lefty.
He acted in the traditional way for the Russian peasant, as in a joke, with the help of a grinder, pliers and some kind of mother ...
Aerodynamic bullets in the most primitive, but workable form are made from ordinary screws with a diameter of 4,5mm., Long 7,5 millimeters. Accordingly, an air rifle with a barrel diameter 4,5mm is used to fire such holey bullets. So far this will be enough to test the effectiveness of the method of aerodynamic acceleration of a bullet.
So in the picture in front of you are the world's first aerodynamic bullets (or aren't they the first?):
Threads play the role of aerodynamic planes, at the same time they twist a bullet around the axis of movement using the effect of "oblique sail". Air can flow freely through the threads (three full turns of the thread) and between the threads and the walls of the barrel (the real diameter of such a “holey” 4,4mm bullet.). The window for the free passage of air is a quarter of the cross section of the barrel, the bullet turned out really leaky.
Naturally, there is no balance between such a bullet, a layout ,,, - that you will take it from it ... But theoretically such a leaky bullet should fly much better than a regular lead bullet. It remains to test the theory in practice, so it was the turn of experienced shooting.
"And the experience, the son of difficult mistakes and ... .."
Further from modesty I will not continue the quotation.
Experienced shooting was made from this air rifle, it is not a rifle, the barrel is not rifled.
Crosman Recruit RCT525X
The choice of weapons is not accidental, I was looking for such a smooth-bore thing. A rifled barrel for an aerodynamic bullet is absolutely not needed and, moreover, is harmful. The low speed of the bullet and the lack of balancing in the layout leads to yawing it in the barrel, and it clings to the rifling of the barrel and begins to tumble in flight. This was verified by experience, hence the name of this section of the article.
In addition, this pump-type shotgun and the strength of the shot depends on the number of pump strokes, so that the effectiveness of aerodynamic bullets can be tested on different volumes of a gas charge.
Here are photos of shooting on an aluminum sheet 1,2mm thick, the rifle is pumped up in both cases in seven strokes, which is about a third of the maximum power of this weapon. Left standard lead bullet weighing 0,51 grams, right aerodynamic bullet:
As you can see, the usual bullet did not have enough energy to break the aluminum sheet, and the aerodynamic bullet pierced the sheet through. Comments, as they say, are superfluous.
Obviously, if the handicraft done literally on the “knee” surpasses in its characteristics factory products with centuries-old verified technology, then this is very serious. If such an aerodynamic bullet is made at the factory, with the calculated configuration parameters, balanced, made to produce a specially shaped barrel for firing, then the result will be even more impressive.
And this will be done, so in the part of aerodynamic bullets for pneumatics there will be a continuation, the main thing will be the study of accuracy of fire, there is good reason to assume that even in this “leaky” bullet will surpass the classic “piston” bullets.
But pneumatics is only a test of an idea, and if even at this primitive level a significant positive effect is achieved, what will happen if this technology is applied in powder powder systems?
Such bullets with which tourists were killed on Dyatlov's pass in the distant 1959 year will turn out ...
But from this place, please, in more detail ...
No need to be an alien, to make such an aerodynamic bullet, it could well have appeared in the last century, for example in Germany during the Second World War.
It was in Germany in the middle of the 30 of the last century that the principle of a cumulative explosion was discovered and the shock core method was used for the first time. To combine these technologies with receiver rifle systems is an obvious idea.
The simplest solution is to place an aerodynamic bullet in a conventional unitary cartridge, in which case you can count on the limit at a speed of about 10km / s. This limit is due to the burning rate of gunpowder and limiting pressures in the barrel. A further increase in the speed of the bullet is possible only by replacing the powder with a detonating explosive.
The principal difference between the flow of a chemical reaction by the detonation method (simultaneous chemical reaction over the entire volume of explosives) and combustion (gradual chemical reaction) in the possibility of focusing the pressure drop wave. It is the focusing effect of the blast wave used in the technology of cumulative explosion, which allows to accelerate the gaseous products of the explosion to speed in 200km / sec.
And this is what we need.
The only problem is that it is impossible to detonate the entire volume at once. Although the barrel is not shut up tightly by a bullet, all the energy of the explosion instantly disposed of without breaking the barrel will not work.
The detonating substance needs to be blown up in small portions, at the moment of flight past the aerodynamic bullet. Accordingly, the design of the cartridge is significantly complicated.
This is not a brass “jar” with a cap on the bottom, you can not do without clever and unobvious technologies.
Such technologies are already in use, an example is the Explosive Magnetic Generator (microwave bomb), it uses the method of controlled detonation of powerful explosives for precise crimping of magnetostrictive materials generating microwave radiation.
As a summary of the above, it can be stated that reaching the speed of a bullet in 10 km / s is quite realistic even in the classic version of a unitary cartridge equipped with an aerodynamic bullet.
But a further increase in speed will require a completely different trunk and cartridge (cartridge), in fact, the sleeve will become part of the barrel. And at the same time the sleeve will turn into a very complex engineering product.
"And in the end I will tell…",
"Love us with dirty, clean, everyone will love us ..."
Actually, to begin with, and everything, I foresee a storm of angry accusations and unsubstantiated criticism of the idea of aerodynamic dispersal of a bullet.
Yes, let them say ...
In the next article there will be a video of the actual shooting of an aerodynamic bullet made not “on the knee”, but according to all the rules of aerodynamics, after all, I am a physicist.
Then the moment of truth will come.