WO2024100257A1

WO2024100257A1 - Improved projectile for use in shotgun cartridges

Info

Publication number: WO2024100257A1
Application number: PCT/EP2023/081443
Authority: WO
Inventors: Christopher John MANNING
Original assignee: Ecoshot Ltd
Priority date: 2022-11-11
Filing date: 2023-11-10
Publication date: 2024-05-16
Also published as: GB2624223A; GB202216850D0

Abstract

The Present invention provides an improved projectile configured to be used in shotgun cartridges. This projectile is made of steel thereby replacing lead shot. And has a hollow cylindrical geometry (10) for improved velocity and range compared to a spherical pellet. This cylinder (10) has a sealed end (12) facing forward to improve penetration and allows the projectile to self-align. These projectiles may utilize tapering to further improve the velocity and range of the projectile and may include features such as angular edges, conical points (60, 62), and prismatic steps (50, 70, 72) on the outer face of the sealed end (12) to further improve penetration. Additionally, this geometry allows the projectiles to lock together by coupling the open end (14) of one projectile to the sealed end (12) of another, to be more easily stacked within the shotgun cartridge.

Description

Improved projectile for use in shotgun cartridges

Background:

Shotguns are used for a range of commercial uses such as clay pigeon shooting or hunting a wide selection of quarries, from small birds to deer and boar. As a result, a wide range of different ammunition types has been made for these different uses. Typically, these ammunitions use a plurality of ball projectiles referred to as shot, and this shot has typically been made of lead since the shotguns were invented. However, more recently there has been an effort to ban or phase out the use of lead within such ammunition. For example, in the UK lead shot was banned for wildfowling in 1991, California banned its use for all hunting in 2019, and 19 members of the National Game Dealers Association banned the purchase of game shot with lead shot in 2022. The Health & Safety Executive as the Agency for UK REACH are currently consulting on legislation restricting the use of lead in shooting in the UK. It seems bans may be imminent for other parts of the US and EU nations. Commercial retailers have also started to phase out lead shot from sales. For example, Waitrose has stopped buying game shot with lead shot, and 9 of the largest shooting organisations agreed to phase out lead shot by 2025. One of the main reasons for this ban is that the lead within the shot is poisonous and so possesses an environmental risk, as any shot that misses the target or is left at the site where the shotgun was used, runs the risk of entering the food chain as it is maybe consumed by wildlife or washed into river and lakes. Once in the food chain, these poisonous materials can cause further harm to wildlife and even humans that consume contaminated animals or plant life.

A commonly used alternative to a lead shot is a shot made of iron, in particular, shot made of steel. It is noted that due to steel having a lower density than lead, if the two shots, steel, and lead, are made of the same size the steel shot lacks the same impact as the lead shot, for the steel shot would have a lower momentum at the point of impact and so would exert less energy and force onto the target. To compensate for this steel shot is manufactured to be a larger size compared to lead shot. These larger steel shots provide more impact force per pellet as compared to the smaller steel shot and lead shot but these larger pellets have some other issues.

Firstly, due to the pellets of the shot being larger, fewer pellets can be packed into a cartridge, for example, a 30gram cartridge can hold 289 lead pellets compared to only 206 steel pellets. Shot fired from a shotgun gradually spreads laterally and longitudinally as it travels down range, the lateral spread is assessed via the “pattern” typically the % of the shot within a 762mm (30”) circle at the intended target/kil ling range, if less shot is used the pattern fails at shorter range. However, as the steel pellets are larger, each pellet would have a larger area of impact on the target, these larger areas of impact mean that the steel pellets would likely have lower penetration as the force per unit area is lower, i.e. the impact force would be spread over a larger area. Also because of their lower density, the steel pellet have lower momentum and so_may exert less force at the moment of an impact compared to lead shot at the same velocity. Also because of its lower density and larger size, the steel pellets impact force deteriorates quicker due to air resistance than lead pellets at range. Both of these factors result in the steel shot having a lower penetrating power compared to the lead shot, especially at longer ranges. Therefore, it would seem that the steel pellet underperforms when compared with the traditional lead shot.

The issues with these larger steel pellets extend beyond the ammunition’s performance. Specifically, the use of these steel pellets can have detrimental effects on the barrel of the shotgun. Shotguns are normally designed with a smooth bore barrel, the last 50mm or so of which is typically of smaller diameter called choke designed to concentrate the shot as it exits the barrel, to reduce overall spread. When firing a lead shot, the pellets that impact the choke may deform under the impact. It is noted that this deformation may cause the pellets to fly erratically and prevent the pellet from penetrating the target, and may also increase the spread of the shot as the deformed pellets change trajectory and deflect away from the rest of the shot. However, this deformation also prevents the pellets from damaging the barrel, as the pellet absorbs the force of the impact rather than exert force onto the barrel.

Steel shot is effectively not deformable and therefore risks damaging the gun’s barrel as the pellets travel down the barrel particularly at the choke. This risk of damage to the gun barrel is further increased by the fact that some steel shot cartridges are designed as High Performance and have a higher muzzle velocity and operate at a higher pressure, specifically 430 m/s and High Performance 1370 bar (transducer). Standard cartridges for steel are 400 m/s proof 960 bar (transducer). This being the higher speed of the pellets as they leave the barrel, to compensate for the shots’ lower density. Therefore, the steel pellets travel through the barrel at a higher velocity and may impact the barrel wall with greater force compared to lead shot, transferring more energy to the barrel as the steel pellets do not deform. This combination of factors results in a higher risk of the gun barrel being damaged each time the gun uses a steel shot cartridge as the steel pellets are more likely to scratch, chip, or otherwise damage the smooth barrel.

Shotgun cartridges also include a wad between the power and shot whose function is to ensure separation of the propellant and the shot providing obturation between the two components and some cushioning of the rapidly accelerating shot load. Historically this has been a felt/fibre material but more recently plastics and other materials may be used. With the development of the plastic wad, shot cups were developed, these encompass the shot column and prevent direct contact between the shot and the barrel. In lead cartridges these prevent deformation and erratic flight of pellets damaged by contact with the barrel, for steel cartridges these prevent the hard steel shot damaging the barrel. It is noted that the cushioning function is not required with steel shot and some of the capacity formally used for this function is used for the shot pellets. Some special cases, like the longer, 31 " 12 bore cartridges, have been developed to increase case capacity and hence the payload when using steel shot. But due to the size of the cartridge, they can only be fired using specialised guns making them an impractical option compared to other cartridges that could be used in a range of shotguns.

Lastly, the higher velocity in the steel shot cartridges may generate additional recoil and make them unpleasant to use, and potentially lowering the accuracy of the shot. This makes the steel shot less desirable commercially, as it would be harder to use these shots for hunting or clay shooting due to this extra recoil, meaning the user would be at a disadvantage, such as from reduced accuracy. Further, the extra recoil may increase wear on the gun, increasing the amount of maintenance the user would need to perform in addition to the increased risk of damage to the barrel described above. So, in summary, the steel shot removes the poison risk present in the lead shot, and may perform similarly in terms of spread and impact force using rounds designed to increase the velocity of the shot, and/or increase shot size thereby increasing the energy the shot delivers to the target. However, these changes increase the amount of recoil caused by the shot and increase the risk of the gun barrel being damaged. These factors make the current steel shot cartridges undesirable, but with more organizations banning the use of lead shot, there seem to currently be no alternatives.

Relevant prior art disclosures include W010/025121 of Pinnacle ammunition company which discloses predominantly spheroidal shot having a V indent in one end of the projectile. WO 01/98727 of Andersson provides spherical projectiles with a small indent in one end of the projectile and various geometries of the head of the projectile. US 3877 3812 of McCoy discloses frustoconical projectiles suitable for stacking.

It is therefore evident that whilst there benefit from the use of steel shot it has many problems seeking a solution.

It is noted that other materials have been considered to replace lead in the shot, including tungsten, bismuth, and even gold. However, these materials presented their own set of problems. Materials like tungsten, with densities similar to lead, are less malleable than lead, which is a relatively soft material, and therefore these alternative materials would likely cause more damage to the gun barrel than the steel shot, as they would also be unable to deform, and due to their higher density compared to steel, they would exert more force onto the barrel during an impact. Further, most of the alternative materials would simply cost too much to manufacture commercially. In particular, the lead shot would cost less than £400 per 1 ,000 to produce 11.1 g/cc ammunition, with steel shot having a similar cost due to the relative abundance of steel. While the alternatives cost in excess of £1400 to produce the same amount of ammunition. Therefore, it is not economic to adopt these alternative materials even if the shot performs as well, or even better than the lead shot. Therefore, there is a need to find an alternative to the traditional lead shot. This alternative needs to be made from a non-hazardous material for a reasonable cost. Additionally, the alternative needs to have a high performance, in the case of these shots, the performance would be determined based on the ammunition spread and penetrating power. Lastly, the new shots would need to be able to hold a similar number of pellets to the lead shot, without risking damage to the barrel of the gun due to the density of the pellets or pressure within the shot’s cartridge. Additionally, the alternative shots should have a similar muzzle velocity to the lead shot, without affecting the gun’s recoil.

Summary:

The present invention in its various aspects is as set out in the appended claims.

The present invention provides a projectile for use in a shotgun cartridge, the projectile being a metal projectile, the metal not being lead or a lead alloy, the projectile comprising the following characteristics: a) the projectile is a hollow cylinder 10 capped at a first end 12 and open at a second end 14 opposite the first end 12, wherein the cylinder tapers over at least a portion of its length toward the second end 14, this defining a tapered section 20,40 and wherein the portion proximate to the first end 12 has one or more flat faces, being perpendicular to the longitudinal axis of the cylinder 10.

There is a need, to replace lead shot pellets. The projectile comprises a metal projectile, the metal used for these projects is not lead or a lead alloy, thereby overcoming the problem of the projectiles’ material being poisonous and therefore an environmental hazard. In particular, lead shot is toxic and if present in game consumed by humans represent a risk to our health with the Food Standard Agency recommending that we should cut down our consumption. Any game shot but not retrieved may be eaten by raptors with lead ingestion widely believed to be a significant factor in reducing raptor populations.

The chosen metal for the projectile would also not have a similar hardness to lead. Specifically, lead is a relatively soft material that can be deformed with little force. This means when a cartridge with a lead shot is fired, the lead pellets will deform when they impact the inside of the gun barrel. This deformation reduces the impact on the barrel reducing the risk of damaging the barrel, however, the deformed pellets would likely deflect to an off-course trajectory, and would likely miss the target, or be unable to penetrate the target if it stays on the right trajectory. As the presented projectile is designed with a shape that would help reduce the pellets’ spread while improving the projectile’s penetrating power it is preferable that the projectile is made of a material that will not deform as the projectile travels down the barrel or when the projectile impacts the target. This way the new projectile design ensures a low spread over a longer range making the shot more accurate while ensuring a sufficient impact force to penetrate the target.

To achieve this effect the new projectile comprises a hollow cylinder capped at a first end and open at the second end opposite the first end. In particular, the projectile comprises a plurality of short hollow cylinders that can be stacked for being placed within a cartridge. Wherein these protectives may preferably be stacked so that the capped end preferably faces the forward end of the cartridge. When fired the stacks thereby travel down the barrel of the gun in columns reducing the chances of the projectiles impacting the sides of the barrel, this means that the projectiles will stay relatively aligned as they travel reducing the overall spread of the shot over a long range. In addition, the sealed end of the cylinder provides the shot with a more aerodynamic shape. When designing the shape of the projectile the length of the cylinder between the sealed and open ends is chosen to be as long as possible while keeping the projectile’s centre of mass proximate to the sealed end. By keeping the centre of mass close to the sealed end of the project, the projectile provides self-aligning via aerodynamic forces as it travels through the air, in a similar way to a shuttlecock. Additionally, the centre of mass will be proximate to the point of impact, on the sealed end of the projectile, this design help to maximize the amount of energy, or force, exerted onto the target when the projectile impacts thereby increasing the projectile’s penetrating power allowing the projectile to penetrate a target more easily when compared to a round pellet used in traditional shots.

In the present invention the term “cylinder” is used. The term “cylinder” herein is hereby defined as being a cylinder (i.e. of circular cross-section) and an elongate prism of symmetrical cross-section. Preferred prism cross sections are a regular pentagon, hexagon, heptagon, octagon, nonagon, and decagon. For convenience, the description uses the word cylinder to encompass the above shapes. The preferred cylinder is a conventional cylinder having a circular, ovoid or ellipsoid cross-section. The most preferred cylinder is a cylinder having a circular cross-section this understanding that the invention is claimed provides modifications of that cylinder so as to arrive at the invention. A circular cross-section is preferred as this provides no angular radial edges but angled edges at the front and rear face with the benefits elucidated herein.

In some cases, the open end of the projectile may be tapered, wherein the projectile will comprise a cylindrical portion coupled to a tapered portion, creating a tapered section towards one of the ends of the cylinder. In some cases, this tapered section preferably extends toward the open end of the projectile. More specifically the projectile preferably comprises a short hollow cylinder with a sealed end, with a hollow tapered portion extending from the open end of the cylinder, up to the projectile’s desired length. This geometry helps to further improve the aerodynamics of the projectile’s shape. In particular, the airflow over the tapered section could allow the projectile to be more aerodynamic and retain speed/energy over a further distance while maintaining the desired alignment and trajectory. It is noted that this tapered tail could further help the projectile’s ability to self-aligning, as the removal of material when forming the tapered portion would push the centre of gravity towards the closed end of the cylinder, as the tapered end would likely weigh less compared to the cylinder projectile, it is noted that when the centre of gravity is closer to the closed end of the projectile the flight of the projectile is more stable as the self-aligning aerodynamic force would be stronger. It is noted that the aerodynamic of the projectile may be improved by lengthening the tapered tail, thereby increasing the surface area to increase the force generated by this surface as the projectile is in flight, however, such extensions may move the projectile centre of gravity towards the open end of the projectile, which in turn may reduce the projectile flight stability and/or penetrating power.

In other cases, the closed end of the cylinder may be tapered instead. In this geometry the projectile provides a hollow cylinder at the open end, with a short-tapered section coupling one end of the cylinder to a flat circular piece with a radius shorter than that of the cylinder, this is to say the sealed end of the projectile would have a shorter radius and would couple to the hollow cylinder via the tapered section. It is noted that this tapered section could be hollow or solid depending on the desired mass of the projectile and the location of the projectile’s centre of gravity. By using this geometry, the airflow over the tapered section would again help the projectile self-align while in flight, though this would have less of an effect, as the tapered section would be smaller relative to the tapered tail described above. However, this geometry also reduces the size of the impact surface, by reducing the radius of the sealed end. This smaller surface increases the amount of force exerted on the target at the point of impact, as the force is spread over a smaller area, this may increase the penetrating power of the projectile, relative to the projectile with the tapered tail.

As previously noted, this tapered section would likely have less weight compared to a hollow cylinder of the same length, therefore the projectile wherein the tapered section extends towards the sealed end would have a centre of gravity that is further from said seal end. As stated, the centre of gravity needs to be closer to the sealed end to improve flight stability. This may be overcome by having the tapered section be solid instead of hollow, though the centre of gravity would still be pushed back slightly by the tapering. Alternatively, to overcome this problem, the sealed end could comprise a weighted step. That is to say, the flat sealed surface may comprise a small solid cylinder that extends away from the tapered section. Thereby forming a structure similar in shape to a coin on the front-facing surface of the projectile. As noted this extra step on the seal end brings the centre of mass back towards the sealed end of the projectile, to help increase the self-aligning forces as the projectile travels through the air. It is also noted that the edges of this coin-like step would preferably be shaped, this way the angular edges help to improve the cutting power of the projectile. This will help increase the likelihood of the projectile creating a clean cut into the target, this means the projectile can enter the target with more momentum and therefore will likely create a larger, or at least deeper wound, which may be preferable when used to hunt larger game.

In other cases, the sealed end of the projectile may comprise a point that extends from the projectile away from the open end. It is noted that this point may be easier to form compared to the coin-like step described above, by making the front of the projectile solid and removing the excess material. The added weight of the point brings the centre of gravity towards the sealed end of the projectile. The point may also help the projectile penetrate a target as the force of the impact of the projectile would be concentrated onto the tip of the point. However, it is noted that the loss of the step, more specifically the angular edge of the step, would reduce the projectile cutting power. Therefore, it may be preferable for the front face of the projectile to comprise a step between the edge of the projectile and the conical point, thereby creating a angular edge around the rim of the projectile to allow the projectile to cut the target more easily while maintaining the improved penetration from the point.

In some cases, the front of the projectile may comprise multiple steps. As with the previous example each step is formed by adding a short solid cylinder with a smaller radius to form coin-shaped steps. These steps move the projectile’s centre of gravity to the sealed end of the projectile, again this helps improve the projectile’s penetrating power and ability to selfalign. It is also noted that the edge of each of these steps is preferably angular, i.e. not rounded but coming to an apex at the junction of sides to further improve the projectile cutting power, as each edge assists cutting into the target by providing a high force per unit area at the angular edge.

In some cases, both ends of the projectile may be tapered as described above. By having both ends tapered the projectile receives the benefits of both long-range due to the tail increasing the projectile’s travel velocity and the increased penetrating power created by the smaller sealed end. Another reason to have both ends of the projectile tapered is to allow the projectiles to better lock together when the projectiles are stacked. Preferably the projectiles are stacked into columns before being loaded into a shotcup or cartridge, or for storage, as such a column allows the projectiles to be arranged into layers and help increase the number of projectiles the cartridge or container could hold. More specifically, this presents two ways of manufacture: Projectiles aligned in a shot cup and the whole unit installed into the cartridge. Or wad and shot cup are inserted into the cartridge and the projectiles a placed aligned in to the combined unit.

When in use these stacked columns, i.e. stacking, of projectiles may be more stable within the cartridge shell, meaning the columns rest upon each other and lay in layers thereby applying less pressure to the interior of the barrel than shot which flows, which may help reduce the outward pressure the projectiles exert onto the barrel as there is less radially outward pressure exerted by the level column compared to the tightly packed spherical pellets.

The presented projectile overcomes this problem as each of the individual cylinders of the claimed projectiles are relatively short, and are interlocked with the open end secured in the closed end and vice versa to form long columns. When these stacks travel through the air, any forces, like turbulence, that would misalign the long cylinder shots would instead cause the stack to come apart. And as mentioned above, the sealed ends of the projectiles at the front of the projection can produce aerodynamic forces that may help increase or decrease the separation of the projectiles according to the intended use. Therefore, the projectile stacks provide the same benefit as the long cylinders by reducing the force the shot exerts onto the cartridge and the barrel of the gun while allowing separation of the stacks as they travel in the air due to turbulence as they travel towards the target to deliver a multitude of projectiles to the target in a similar way to spherical shot.

It is noted that this stacking is preferably achieved by interlocking the front surface of the sealed end of the projectile with the aperture in the open end of another projectile. In particular, the rim of the open end of a first projectile will lock to the sealed end of another projectile. There it is preferable for the projectile to include a step on the front face of the projectile so that there is a surface for the rim of the open end of the projectile to interlock with. For this reason, the geometry where the front of the projectile comprises one or more coin-like steps may be preferable as the ends of the projectiles can better lock together with a plug-and-socket-like coupling. This structure makes the coupling between the projectiles more stable as the point of contact has a larger surface area, especially when compared to a projectile with a flat surface or point on the front face, as these geometries have a lower area of contact between the projectiles. It is also noted that if the sealed end of the projectile comprises multiple steps they may couple to a range of projectiles in particular the user could have projectiles with different size apertures in the open end, this may be achieved by having projectiles made of cylinders with different thicknesses, which could be achieved by using different size bores during production, or by adjusting the angle of the projectiles tapered tail when the open end is tapered. It is noted that each of these changes could affect the performance of the projectile as the thicker walls increase overall mass and therefore may affect the flight stability as it shifts the centre of gravity, and the impact force of the projectile, therefore thicker ammunition is understood to have a lower effective range. In contrast, increasing the curvature of the open end may affect the projectile’s top speed and the effectiveness of the projectile self-alignment as the curved surfaces increase the aerodynamic forces acting on the tail as the projectile travel through the air. Therefore, the user could adjust these factors to produce ammunition best-suited force a specific use or use a range of thickness and curvatures within the same cartridge or shell to make ammunition that can be effective across multiple ranges at once, as the more curved projectiles may be more effective at long range, while the heavier projectiles are more effective at short range, note that the plurality of steps allow all these different size projectiles to still interlock.

The stacking may also be achieved by interlocking the aperture in the open end of one projectile with a groove in the closed end so that the sealed end provides the socket in the open and the open end a plug for this form of stacking. Whilst this may be advantageous in providing a ridge on the closed, front, surface of the projectile so as to improve cutting power it also may reduce aerodynamic efficiency and is not preferred.

Regardless of the cylindrical geometry that is chosen, each of the above-mentioned projectiles is configured to be loaded into a cartridge or case configured to be fired from a shotgun, or similar firearm, wherein each cartridge contains at least 5 projectiles. When placing the projectiles into these cartridges it is preferable for the projectile to be arranged in columns with the sealed ends of the projectiles facing forward when fired, these columns should be thin enough for multiple columns to fit side by side within the cartridge.

More specifically, it is preferable for each projectile to have a maximum diameter equal to, or proximate to the diameter of a spherical pellet used in an equivalent shotgun shot. For example, when loading the projectile into a 12-gauge cartridge, the diameter should be the same as the diameter of the pellets loaded into a 12-gauge cartridge. With these dimensions, the hollow projectile can have a higher density, as the cylindrical shape has more mass than the equivalent spherical pellet of the central section this increase the impact force at equivalent ranges. With these criteria in mind, it is preferable for the projectile to have a diameter of less than 9mm and more than 2mm depending on the size of the casing and the intended use, the projectiles preferably have a length of less than 27mm and more than 2mm, again the length may be chosen based on the intended use, the size of the casing or the choice of diameter. It should be noted that the longer length may allow the projectile to move faster, though it also makes the flight path less stable meaning the projectile is more likely to scatter away from the target. Also, a wider projectile increases the overall mass and may improve penetrating power as the projectile thereby has a larger cutting edge, however, if the projectile is wider fewer projectiles would fit within the casing. Therefore, the ranges presented above provide the best compromise for the length and width of the projectile, though the projectile may be provided in a range of sizes within these ranges based on the intended quarry, like how the pellets used in buckshot rounds are larger than that in duck shot rounds when sizing the projectiles in this manner the diameter of the round should be similar to that of the pellet for an equivalent round.

It is noted that the projectiles may be formed by using a rolling, cold forming or punching process or mould to form a solid cylinder with the projectiles’ desired dimensions, after which a bore may be used to form the open-end aperture and to hollow out a portion of the cylinder between 10% and 95% of the length of the projectile. It is noted that it is preferable for the bore to hollow out only a portion of the cylinder, this way there is more weight near the sealed end of the cylinder. However, to receive the aerodynamic benefits of the hollow cylindrical shape the bore must hollow out at least half of the cylindrical shape, therefore it is preferable for the bore to hollow out between 50% and 90% of the length of the projectile.

Regardless of the size chosen for the projectile, the projectiles are preferably stored within cartridges suitable for use in a shotgun such that the projectiles are stacked into columns within the shotcup and cartridge. A shortcup prefers to a liner for a conventional cartridge, such as a plastic liner which serves to provide additional lateral buffering between the projectiles on the gun barrel and having a base they may optionally be configured to provide an element of cushioning such as to perform the function of wadding. Said cartridges may also include such wadding to cushion the projectiles and help reduce perceived recoil when fired. The shot cup consists of a base which may be coterminous with the wadding and sides that extend to the full height of the projectiles to prevent direct contain between them and the barrel wall. This wadding may comprise a shot cup made of plastic, such as a biodegradable plastic, that surrounds the projectiles. This shot cup may include one or more slits in the sides of the shell so that the sides of the shotcup may be overlapped and can move to help dissipate the force exerted when the gun is fired. The shot cup walls may also have a plurality of ridges or radial ribs, wherein the ridges are angled relative to the length of the cartridge to provide cushioning to the barrel of the gun when using tightly choked guns. The bottom of the shot cup may also include a castellated base such features may be in the form of flexible hollow cylinders arrange to be perpendicular to the length of the cartridge, wherein these features can flex and compress to absorb the recoil force when the gun is fired. It is noted that other types of shot cups are available such as a cardboard/paper sleeves, felt including vegetable fibres that surrounds the projectiles within the shot cup. However, the plastic shot cup shell may be preferable as its more ridged shape ensures the wading does not disrupt the projectile stacks as they leave the cartridge. Detailed Description

The claimed invention is illustrated within the following figures:

The figures depict projectile geometries.

Figure 1 - depicts the simplest example of the projectile comprising a hollow cylinder with a sealed end.

Figure 2 - depicts the example projectile from figure 1 with a tapered open end.

Figure 3 - depicts the example projectile from figure 1 where the sealed end is tapered.

Figure 4 - depicts the example projectile of figure 2 wherein the tapered end is extended.

Figure 5 - depicts the example projectile from figure 3, with the addition of a cylindrical plat on the outer surface of the sealed end.

Figure 6 - depicts an example projectile with a tapered section at each end of the cylinder and a cylindrical part on the outer surface of the sealed end. The parts cooperating in a plug (sealed end) and socket arrangement (open end).

Figure 7 - depicts an example projectile with a tapered section at the open end of the projectile and a conical point covering the outside surface of the sealed end of the projectile.

Figure 8 - depicts the example projectile of figure 7, wherein the conical point covers only a portion of the outer surface of the sealed end creating a step around the conical point.

Figure 9 - depicts an example projectile with a tapered section at the open end of the projectile and a plurality of steps mounted to the outer surface of the sealed end, comprising a trapezoidal step and a cylindrical step.

Figure 10 - depicts exemplary results of testing the different example projectiles, these results show examples of:

A- Stable flight and clean cut in a target

B- Near stable flight

C- Unstable flight

D- Spherical pellet the blunt form creating a blunt hole in the target which partly selfseals

Figure 11 - depicts results comparing the velocity of the projectile from figure 9 with a spherical steel pellet, over a range of 5 to 50 meters. Figure 12 - depicts examples of the claimed projectile being stacked within a shot cup - side view.

Figure 13 - depicts examples of how the claimed projectiles can be arranged within a shot cup - end view.

Figure 14 - depicts an example projectile otherwise as figure 6 with the parts cooperating in a plug (open end) and socket arrangement (closed end).

Figure 15 - depicts a projectile not having a projectile cavity.

The claimed invention comprises the following parts

10 - cylindrical projectile

12 - sealed end

14 - open end

14A - end

16 - projectile cavity

20 - tapered tail

30 - front tapered section

40 - Extended tapered tail

50 - cylindrical step/plate

60 - conical point covering the entire sealed end

62 - conical point covering only part of the sealed end

70 - a plurality of steps/plates

80 - stack projectile columns

90 - cartridge casing

100 - larger projectile

110 - Ridge

The claimed invention provides a projectile suitable to be used in place of the spherical pellets used within shotgun cartridges. For current shotgun ammunition, two forms of pellets are commonly used; the first is lead shot pellets the other is steel shot pellets. Lead shot has been used since the shotgun’s inception comprising a plurality of small dense spherical pellets, the problem with such ammunition is that lead used to produce them is toxic, if present in game consumed by humans represent a risk to our health with the Food Standard Agency recommending that we should cut down our consumption. Any game shot not retrieved may be eaten by raptors with lead ingestion widely believed to be a significant factor in reducing raptor populations.

The use of steel shots became the most common alternative to the toxic lead shot, further, with organisations starting to ban the use and/or sale of lead shot, the use of steel shots is becoming more common. These shots comprise spherical steel pellets rather than the lead pellets described above. However, due to steel’s lower density, the steel pellets have to be made with larger dimensions to have the same impact force as the lead shot. This results in steel shot cartridges containing fewer pellets, for example, a 30gram cartridge can hold 289 lead pellets compared to only 206 steel pellets. Shot fired from a shotgun gradually spreads laterally and r longitudinally as it travels down range, the lateral spread is assessed via the “pattern” typically the % of the shot within a 762mm circle at the intended target/killing range, if less shot is used the pattern fails at shorter range. To overcome this longer 31 " 12 bore cartridges have been developed to address this problem, they require specially designed guns while to deliver sufficient energy high-performance steel shot has been developed, this generates higher muzzle and hence down range velocity but requires guns proofed for high- pressure loads:

• Standard proof 960 bar (transducer) - 400m/s velocity

• High Performance 1370 bar (transducer) - 430 m/s velocity.

When fired spherical shot flows laterally and radially, the radial flow impacts on the interior of the barrel, the large sizes of the pellets increase the radial pressure within barrel as the mass of the pellets would be concentrated onto the fewer points of contact between the cartridge and the pellets and the larger size of the pellets may mean there is more mass pushing onto each point of contact, which can cause the barrel to deform or be abraded under the radial force caused by this increased pressure. In addition, the larger steel pellets are more likely to impact the sides of the barrel when traveling through the barrel of the gun, when such impacts occur the steel pellets are more likely to wear, or even damage the barrel of the gun. Steel shot by it hardness can damage barrel walls, this is partly overcome by the use of protective shot cups that provide a plastic/paper or fibre barrier to prevent direct contact with the steel shot and the barrel wall. In comparison despite its higher density the lead pellets are relatively soft and can deform on impact to absorb the force of such impacts, while the steel pellets do not deform and so transfer more energy into the barrel of the gun. Therefore, there is a need for an alternative shot that is made of a non- poisonous material, that provides a similar number of projectiles to lead shot and delivers similar down range performance without damaging gun barrels when fired

Figure 1 depicts the simplest example of the claimed bullet-like projectile, wherein the projectile comprises a hollow cylinder 10 made of steel, wherein the hollow cylinder 10 is open at one end 14 and sealed at the other end 12. In use, the pellets would be aligned so that the longitudinal axis of the projectile aligns with the length of the gun’s barrel with the sealed end 12 facing forward, towards the target. It is noted that the hollowed-out cylinder 10 provides for the centre of mass to be towards the closed end of the projectile 12.

It is also noted that the cylindrical shape of the projectile may provide aerodynamic forces that would align the projectile as it travels through the air, with such a force being generated as the air flows over the curved cylindrical surface. This effect is improved due to the sealed end 12 of the projectile having more mass compared to the open end 14 moving the projectile’s centre of mass closer to the front side of the projectile, giving the projectile aerodynamics similar to that of a shuttle cock, where the extra weight on one side and long hollow body allows the projectile to self-align as it travels through the air.

In addition to the self-aligning feature described above, another benefit to having one end of the cylinder sealed is that the face at the sealed end 12 provides an improved impact surface for when the projectile hits the target, as the sealed end 12 would have a greater surface area compared to the curved face of the cylinder 10 allowing more energy to be transferred to the target providing the projectile with better penetrating power. It is noted that the edge of the cylinder may be angled to provides a cutting edge around the sealed end 12 and thereby increase the projectile’s penetrating power, as the projectile would be able to cleanly cut the target instead of using blunt force to punch through, this would allow the projectile to travel further through a larger target.

It is also noted that the penetrating power of the projectile may be improved further by adding more weight to the sealed end 12 of the projectile, this could be achieved by reducing the length of the cavity 16 through the centre of the cylindrical projectile 10 and leave a portion of the projectile’s body near the sealed end 12 solid instead of hollow. However, this additional weight may reduce the effects of the aerodynamic forces generated as the projectile travels through the air, both because the projectile has more weight that the force would need to work on, but also because the extra mass would move the centre of mass away from the sealed end 12. This may result in the project having a lower effective range, as the self-aligning forces would be reduced decreasing the stability of the flight of the projectile. This mass could also cause the projectile to have a shorter fall distance, meaning the projectile would travel a shorter distance before falling to the ground. Therefore, the user needs to compromise between the impact force of the projectile and the effective range when changing the mass. As mentioned, the user can adjust the mass of the projectile during production by changing how much of the projectile’s length is hollowed out when forming the cavity 16 through the open end 14 of the projectile.

In particular, the projectiles would be formed as a solid cylinder that is then partially hollowed out using a bore or created by the cold forming/punching process. The bore may hollow out between 10% and 95% of the length of the projectile, ensuring one end of the projectile remains sealed. Note that the length of the cavity 16 would depend on the intended use of the ammunition, projectiles with more of the length bored would have a longer range due to the lighter weight and improved aerodynamics, while boring less of the projectile length bored would increase the weight and in turn the amount of force delivered to the target, increasing penetration at short range and potentially make flight of the projectile unstable. To have a good compromise between range and penetrating power the user may choose to bore out between 50% and 90% of the length of the projectile, as this range ensures the centre of mass is within the front half of the projectile so there will be at least some selfalignment as the projectile travels.

It is also noted that the width or diameter of these projectiles can be chosen based on the intended use, much like the lead and steel shots that are currently used that come in different sizes based on the type of cartridge used. It is noted that the diameter of the projectile cylinder 10 would preferably be the same as that of the equivalent lead pellet. This means the projectiles could have diameters that are less than 9mm and more than 2mm depending on the size of the casing and the intended use. Similarly, the projectiles would also have lengths that are less than 27mm and more than 2mm, wherein the length may be chosen based on the intended use, the size of the casing, or the choice of diameter. It is noted that the length of the projectile is also chosen to be as long as possible while keeping the centre of mass close to the sealed end, likely within the front 25% of the projectile’s length. As the longer projectile would increase the surface area of the cylinder’s curved surface which would increase the aerodynamic forces that allow the projectile to travel at higher velocities and in doing so improve the projectile’s ability to self-align, however, this self-alignment will not work if the centre of mass is in the centre of the cylinder as it needs to be directed towards the sealed end 12.

Figures 2 and 3 depict example projectiles with improved geometries. To be specific the projectiles of Fig.2 and 3 have been improved by adding tapered surfaces to the cylindrical projectile. In the case of Fig.2, the tapering has been added to the open end 14 of the projectile, forming a tapered section that covers the open half of the projectile, meaning the half of the projectile that will be hollowed using the bore, creating a tapered tail 20. This tapered tail 20 would help improve the aerodynamics of the projectile as the angled surface would reduce the air resistance caused by the airflow moving over the surface of the projectile. This may result in the projectile traveling further, improving the effective range of the projectile. Also, the tapered tail 20 would likely use less material compared to a cylinder of the same length, so this tapered tail 20 may move the projectile’s centre of gravity closer to the sealed end 12 compared to a cylindrical projectile of the same length.

Figure 3 shows an alternative geometry wherein the front half of the projectile, near the sealed end 12, is tapered. Specifically, the projectile of Fig.3 comprises a hollow cylindrical portion 10 and a cylindrical, or circular plate that forms the sealed end 12, with a radius and length smaller than the hollow cylinder 10, coupled together by a tapered portion 30. Wherein the tapered portion 30 reduces in radius as it approached the sealed end 12. This tapering may improve the projectile’s penetrating power, as the surface area of the sealed end 12 is reduced, meaning the force created when the projectile impacts the target is spread over a smaller area, so more energy would be transferred to the target, compared to a similarly sized cylindrical projectile. It is also noted that the sloped surface may help reduce the air resistance acting on the projectile, this again allows the projectile to reach and/or maintain a higher velocity which can further increase the projectile’s impact force. However, it is noted that the tapered end would have less material compared to a cylindrical projectile, thereby reducing the weight of the sealed end 12 and thereby moves the projectile’s centre of mass away from the sealed end 12 of the projectile, this may destabilize the projectile’s flight. Note that having the tapered portion 30 of this projectile be solid rather than hollow could help reduce this effect as there would be more weight in the front half of the projectile, however, the tapering would still result in the centre of mass moving away from the sealed end 12, though to a lesser extent then if the tapered portion 30 is hollow.

Figures 4 and 5 depict geometries that try to correct the deficiencies in the geometries from Figures 2 and 3. In Fig.4 the tapered tail 20 depicted in Fig.2 has been extended so that the extended tail 40 is longer than the cylindrical portion 10 of the projectile. As the tail 40 is extended the surface area of the tail 40 is increased thereby increasing the aerodynamic forces generated when the projectile travels through the air. It is also noted that the tapered tail 40 would be hollow so that the tail 40 would have little weight compared to the cylindrical portion 10. This means the long tail 40 would have little effect on the position of the centre of mass, compared to the projectile in Fig.2, though the centre of mass would still be removed from the sealed end. Though the projectile may still suffer from a lack of stability due to this shift in the position of the centre of mass the additional force generated by the extended tail 40 would help improve the stability slightly. Figure 5 depicts a geometry that seeks to improve the design from Fig.3 by adding more weight to the sealed end 12 of the projectile, by adding a protruding feature to the flat face of the sealed end 12. In particular, the projectile has extended the sealed end 12 away from the projectile, thereby forming a step 50 on the outer surface of the sealed end 12. This extra mass moves the centre of mass closer to the sealed end 12, giving the projectile more stability as it moves through the air. The edges of the depicted cylindrical step 50 on the front of the projectile may also be angular to increase the projectile’s cutting power. It is also noted that the step 50 on the front surface of the projectiles may have different shapes, for example, the step may be trapezoidal instead of cylindrical to improve the aerodynamics by tapering the step, in a similar manner to the tapered section 30.

Figure 6 depicts an example geometry that utilizes the tapered tail 20 from figures 2 and 4, with the tapered front 30 and protruding step 50 from figure 5. This geometry would be cable of retaining velocity compared to each of the previous geometries as it utilizes tapering at each end 12,14 of the projectile to improve the projectile’s aerodynamics, reducing the amount of air resistance on the projectile as it travels. This projectile would also have improved penetrating power due to the step 50, or raised portion, on the front face of the projectile, as this would bring the centre of mass closer to the front of the projectile and potentially provide a cutting edge if the edge of the step is angular. Note that in the depicted example the cavity 16 created using the bore has only hollowed out the tapered tail 20 of the projectile, to ensure there is more weight on the front half of the projectile, though in some cases the cavity 16 may also extend into the tapered section 30 at the front of the projectile. By extending the length of the cavity 16, into the tapered section 30, the centre of mass would move closer to the sealed end 12 of the projectile. As previously noted, having more mass on the front of the projectile and having the centre of mass closer to the sealed end 12 increases the projectile’s ability to self-align thereby giving the projectile a more stable flight. Note that the user may want the front tapered section to be solid to increase the total mass of the projectile to increase the projectile’s impact force, as this extra mass would likely increase penetrating power at the cost of lowering the projectile’s effective range.

Figures 7 and 8 depict example geometries for the claimed projectile which uses the tapered tail 20 on the open end 14 of the projectile and adds a conical point 60 to the outside of the sealed end 12. In these geometries a point has been added to the outer surface of the sealed end 12, such a point can be formed by cutting away the material from the sealed end 12 of the cylindrical portion of the projectile 10 or affixing a conical point to the front face, it is noted that the point 60 would greatly increase the projectile penetrating power as the force of the projectile impact is focused onto a single point. The extra material on the point of the projectile would also improve stability by moving the centre of mass closer to the sealed end 12 of the projectile for improved stability. However, it should be noted that the points would provide less material, or at least less mass compared to the solid flat plate, or step 50 of the same length, so the point would likely provide less stability by comparison.

It is also noted that the point 60 in Fig.7, which covers the entire front face of the projectile may have better penetrating power as sides of the conical point can have a steeper gradient, and therefore a more angular point. But it is noted that these projectiles may have less cutting power, as there is no longer a cutting edge around the edge of the cylindrical portion 10 of the projectile, or the step 50 on the front face of the projectile. This means that once the projectile has penetrated the target it has to rely on blunt, or punching force to move through the target. This can result in rough or jagged would as the projectile tears the target rather than cutting which may result in smaller would as the wound is less likely to propagate through the target. The projectile in Fig.8 tries to overcome this issue by using a smaller conical point 62 which covers only a portion of the projectile’s front face so that there is a flat plain, or step between the edge of the projectile and the edge of the conical point 62. This edge would preferably be angular, thereby providing the projectile with a cutting edge that may cut through the target after the projectile penetrates. This allows the wounds created by the projectile to propagate through the target increasing the chances of a kill shot when hunting as the wound inside the quarry would be larger.

Figure 9 depicts the preferred geometry for the projectile. In this geometry, the conical point 62 from Fig.8 has been replaced with a plurality of plates, or steps 70,72, on the front face of the projectile. In doing so the projectile has a plurality of angular edges for better penetration and cutting power, it is also noted that the smaller front step 72 would provide improved penetration compared to a larger flat face, though not as much as the point 60,62, though because of the relatively small size of the projectile overall the difference between the small step 72 and the conical point 60,62 is likely minimal. Note that in the depicted example the wider step 70 has sloped edges, giving the step 70 a trapezoidal shape, which would help improve the aerodynamics of the projectile in the same manner as the tapered section 30 on the front half of the projectile, by reducing the air resistance acting on the projectile as it moves through the air. It is also noted that the projectile may comprise more steps in addition to the ones depicted with each step having a smaller radius as they move away from the cylindrical portion 10 of the projectile. The extra weight provided by the steps 70,72, compared to the conical points 60,62 and a single step 50, would help to move the projectile’s centre of mass closer to the sealed end 12 for a more stable flight when traveling through the air. It is also noted that in the depicted example only the tapered tail 20 is hollow, however, the cavity 16 may be extended to hollow out at least a portion of the cylindrical portion 10 at the front of the projectile, and possible the first step on the front of the projectile to move the centre of mass closer to the sealed end 12 of the projectile.

As before do we need a Figure showing the with a plug-and-socket-like coupling with the closed end aligned within the open end and conversely the opposite, it’s partly shown in Fig 12.

Figures 10 and 11 depict the results gathered when testing the projectiles depicted in Figs.1 to 9 and comparing them to a spherical steel pellet made of the same steel as the projectile and with the same maximum diameter as the largest diameter of the cylindrical portions 10, or tapered portions 30 of the projectile. Figure 10 depicts 4 exemplary results from the testing. In particular, result D depicts the result when using the spherical pellet. As can be seen in figure D there is no clear hole through the target, instead, the pellet has punched a hole through most of the target without penetrating all of the way through the target. This is because the pellet has to use blunt force to penetrate the target, though the force used to do so is spread over the entire surface area of the spherical pellet, resulting in the pellet having relatively low penetrating power resulting in the tearing seen on the target. Results A, B, and C depict the differences caused by changing the geometry of the projectile. Note that these results have been ordered from best to worst, based on how clean the project cuts through the target as this would represent the best penetration through a larger target.

Result C depicts what happens when the projectile has an unstable flight path, note that in this result the projectile has penetrated through the target, but has left an elongated wound with torn edges. This result shows an improvement over the pellet in terms of penetration, but it has still relied on blunt force to tear the wound rather than cutting cleanly into the target. Given the shape of the hole, the projectile may have rotated before hitting the target so that the cylindrical surface hit the target rather than the sealed end 12, which would reduce the penetrating power of the projectile. This result shows why it is important to have the centre of mass close to the sealed end 12 of the projectile, as it will allow the projectile to self-align with the sealed end 12 facing the target. This result was more typical for the geometries depicted in Figures 1 to 4, which were completely cylindrical or had half of the projectile tapered with a flat front face, with no protruding features.

Result B shows a cleaner cut, with a more spherical wound showing on the target, however, there is still some tearing towards the bottom of the hole. This suggests that there was a slight miss alignment when the projectile hit the target, that is to say, the projectile was likely not perpendicular to the target at the point of impact and was not able to self-align as it passed through the target. In the specific example shown it seems the projectile may have angles upwards slightly before hitting the target, or at the moment of contact as the projectile began to penetrate the target, resulting in the clean cut having a tear around the bottom. This result indicates a more stable flight path and cutting power compared to result C and the pellet. This result was commonly seen for the geometries in Figures 5 and 6, though the direction of the tearing changed, it seems the weighted step 50 at the front of the projectile did improve the stability of the flight path though there was still some instability. It is noted that the stability of these projectiles may have been improved by increasing the length of the cavity 16 within the projectile thereby moving the centre of mass closer to the sealed end 12.

Result A show the best results, with a clean spherical cut through the target, showing better penetration, and therefore showing better wound propagation through a target. This result is also an indication of a stable flight path showing that the projectile was able to self-align on route to the target. This result was seen sometimes with the geometries from Figures 5 and

6 but was more common when using the geometries depicted in Figures 7 to 9. It seems the additional mass from the conical points 60,62 and additional steps 70,72 help improve the stability of the projectile. It is noted that the projectiles that had the conical point 60 covering the entire front face of the projectile showed slight tearing around the edge of the cut possibly due to the projectile lacking the cutting edge around the rim of the cylindrical portion 10 that was present in the other projectiles. This test showed that the geometries in Figures

7 to 9 produced the best results at a given range, due to better penetration compared to the other geometries and the spherical pellet.

In another evaluation, the velocity of shots was measured over a range from 5 meters to 50 meters. In this test, the spherical steel pellet was compared to a projectile with the preferred geometry depicted in Figure 9. As can be seen in the result the projectile consistently had a higher speed at each range. More importantly, the projectile has a little drop-off in velocity over 50 meters, with the velocity falling less than 20 m/s between 5 and 50 meters (a 17m/s difference to be exact). Compared to the pellet whose speed fell over 70m/s over the same range. This shows how the projectile has better penetration and a longer effective range compared to the currently used pellets. With a higher average velocity, the projectile would be able to travel a greater distance within the same time, and due to the faster velocity, the projectile would also have a greater momentum when hitting the target allowing for greater penetration, as more energy would be transferred to the target.

Overall, the results of both tests suggest that the preferred embodiment for the projectile would be an improvement over the pellets currently used in shotgun cartridges. As each of the tested geometries appeared to show better penetration in the first test, although certain geometries were able to penetrate the target more cleanly than others, each penetrating better than the pellet based on the amount of tearing. In the second test, the better performing geometries from the first test show greater velocity over a range of distances compared to the pellets, showing how the projectile would be able to transfer more momentum to the target for better penetration and would have a greater effective range as the projectile’s velocity had a slower drop-off rate. It is noted that the more stable flight path and higher velocity means the projectile will have a lower risk of damaging the gun barrel, as there is a lower chance of the projectile miss aligning and impacting the gun barrel.

It is noted that the geometries in Figures 8 and 9 had similar performances when testing a single projectile. However, the geometry in Figure 9, with multiple steps 70,72 on the front surface is preferable when using multiple projectiles at once, as is the intention for these projectiles. The reason for this preference is indicated in Figure 12. For when the projectile is placed within a shot cup the projectiles will be stacked to form columns 80 within the container. Specifically, all the projectiles would be arranged to face the same direction with the open end 14 of one projectile resting on the sealed end 12 of another projectile. In the projectiles that feature a step on the front face, the tapered tail 20,40 can be angled so that the rim of the open end engages the rim of one of the steps 70,72 on the sealed end 12, coupling the projectiles together like a plug and socket. It is noted that the features on the front face of the projectile, the smaller steps 72 or conical points 60,62 could then engage, or contact the inner surface of the projectile cavity 16 to make this coupling more stable and in turn make the column 80 more stable. It is noted that the smaller step 70 would have better stability as the areas of contact between projectiles would have a larger surface area, reducing the risk of the column 80 falling apart.

The advantage of using these stacked columns 80 within a cartridge is that they would reduce the radial pressure acting on the cartridge casing 90. As the interlocking projectiles could rest in organized rows and would have a larger area of contact with the casing wall, as shown in Figure 13. This means that the weight of the projectiles is spread over a larger area, reducing the pressure acting on the cartridge. It is noted that this effect could also work when packing different-sized projectiles, for example, the second image in Fig.13 shows a cartridge with a larger projectile 100, such as a slug round, spherical pellet, or simply a larger projectile surrounded by the projectile stacks 80. As with the cartridge with only stacked projectiles the weight of the larger projectile would be distributed over the stacks 80 and therefore have less of an effect on the cartridge casing 90. This reduces the risk of wear to the gun’s chock and barrel.

Using long cylindrical shots, as a possible replacement for the spherical pellets. However, long cylinders may be very unstable, as the slightest turbulence would misalign the cylinders, and the long-curved surfaces would have little to no penetrating power. Further, when using a plurality of cylinders, a single misaligned cylinder could knock most of the other cylinders out of alignment, resulting in a very short effective range. In contrast, the stacked column overcomes this drawback, as any turbulence would cause the stack 80 to break apart, and once the projectiles separate the individual projectiles would self-align as they travel to the target, meaning most or all of the projectiles would be aligned at the point of impact. Therefore, it would seem that the projectiles maintain their improved effective range and penetrating power when used in a cartridge, and reduces the risk of wear to the gun when fired as described above.

Therefore, it appears that the claimed projectile provides an improvement over the currently used lead and steel shots. Firstly, by being made of steel the claimed projectile removes the need for poisonous materials like lead. Secondly, when compared to a pellet with similar dimensions made from the same steel as the projectile, the projectile outperformed the pellet, having both a higher travel velocity and cleaner penetration through the target. Lastly, the preferred geometry for the projectile allows the projectiles to form stable stacks within the cartridge, which eliminates? barrel damage by reducing the radial pressure within the cartridge and reducing the risk of the projectiles impacting the gun’s barrel when fired. Therefore, the claimed projectile provides an overall better performance compared to pellets. Further, the stacked projectiles allow the user to utilize different-sized projectiles within a cartridge by surrounding the larger projectiles with the stacked columns.

Figure 14 provides a projectile geometry with features as previous figures but with a socket and plug geometry. This projectile includes a ridge (110) at the first capped/closed end. The referee ridge preferably has a vertical interface and a chamfered outer space. The chamfered outer face improving aerodynamics while still providing a cutting edge to improve penetration.

Figure 15 discloses a projectile may be configured as a solid “cylinder” (i.e. , as defined earlier and being understood to encompass a number of other similar elongate geometries), the cylinder having a portion of its length from one end to around the centre being tapered. This provides a bias of the centre of gravity towards the front of the projectile. This is shown in figure 15. Such a project projectile may be configured to be stackable, as disclosed herein regarding the plug and socket type approach. This provides a degree of orientation so that even if the advantages of the clear bias of the centre of gravity towards the front of the projectile as provided in the present invention, is not present some degree of stable flight may be possible.

Claims

Claims:

1. A projectile for use in a shotgun cartridge, the projectile being a metal projectile, the metal not being lead or a lead alloy, the projectile comprising the following characteristics: a) the projectile is a hollow cylinder 10 capped at a first end 12 and open at a second end 14 opposite the first end 12, wherein the cylinder tapers over at least a portion of its length toward the second end 14, this defining a tapered section 20,40 wherein b) the cylinder is hollow throughout the length of the tapered section 20,40.

2. The projectile of claim 1 wherein the tapered section 20,40 terminates at the second end 14 and begins between the first and second, ends 12,14 such that a cylindrical portion 10 is present between the first end 12 and the beginning of the taper section 20,40.

3. The projectile of any preceding claim wherein the cylinder tapers over at least a portion of its length toward the first end 12, this defining a leading tapered section 30.

4. The projectile of any preceding claim wherein the portion proximate to the first end 12 has one or more flat faces, being perpendicular to the longitudinal axis of the cylinder 10.

5. The projectile of claim 4, wherein the first end 12 is a flat face.

6. The projectile of any preceding claim wherein the projectile further comprises a protruding feature located on the outside face of the first end 12;

Wherein the protruding feature is concentric with the longitudinal axis of the projectile, extending away from the centre of the projectile in a direction parallel to the longitudinal axis of the projectile, and covers at least a portion of the outside face of the first end 12.

7. The projectile of claim 6 wherein the protruding feature comprises one of a conical point 60,62, cylindrical step 50, trapezoidal step 70, or a plurality of steps.

8. The projectile of any preceding claim wherein the first end 12 of the cylinder is locatable within the aperture formed by the hollow cylinder 10 at the second, open, end 14 of a further one of said projectile.

9. The projectile of claim 8 wherein the projectiles are capable of being stacked in a plug-in-socket manner to form elongated cylinders lengthwise.

10. The projectile of any preceding claim wherein the second end 14 has a flat rim, being perpendicular to the longitudinal axis of the cylinder 10, the rim being of the aperture formed by the hollow cylinder at the second end 14.

11. The projectile of any preceding claim wherein the cavity 16 of the hollow cylinder extends between 10% and 95% of the length of the projectile.

12. The projectile of claim 11 wherein the cavity 16 of the hollow cylinder extends between 50% and 90% of the length of the projectile.

13. The projectile of any preceding claim when configured for use in a number of greater than 5 in a shotgun cartridge between 4 bore and 28 bore or of 0.410” bore.

14. The projectile of any claim 1 to 12 wherein the projectile has a diameter of less than 9mm and more than 2.00mm and a length of less than 27mm and more than 2mm.

15. A shotgun cartridge comprising a plurality of projectiles of any of claims 1 to 14.