Abstract:
A tracer cylinder for use with a shotgun shell to provide an aiming and training aid for shotgun shooting sports, which also can be used for military and police applications. The tracer cylinder, which contains a liquid, is positioned in a shotgun shell above a disk-shaped piercing valve. The shell is loaded into a shotgun and fired. The forces of ignition cause the point on the piercing valve to puncture the bottom of the cylinder, and, when the cylinder is airborne, tracer liquid is released through the resulting opening by physical forces, creating a long-lasting mist or fog cloud that is visible to the shooter. The shooter is provided with a consistent and durable reference, allowing him or her to make effective corrections to his or her shooting technique. The tracer cylinder can be loaded into a shot holder, with or without shot pellets.

Description:
FIELD OF INVENTION 
     This application is a continuation in part of application Ser. No. 11/899,317, which was filed on Sep. 5, 2007. This invention relates to shotgun ammunition, more specifically to tracers used to make the shot visible to shooters. This invention serves as a training aid to improve one&#39;s shooting ability for shotgun sports such as Trap, Skeet or Sporting Clays. It also serves as a shotgun aiming and training aid for hunters, with applications for military and police personnel. 
     BACKGROUND OF THE INVENTION 
     All shotgun sports require the shooter to accurately predict the trajectory of the target. Mastering the lead is the greatest challenge in shotgunning sports. The lead is defined as the distance in front of the moving target, which the shooter aims and shoots at in order to break the target. The particular lead will vary, depending on the application, shot type, shot speed, shooter&#39;s technique, speed and angle of the target, and atmospheric conditions; it can range from a few inches to more than ten feet. 
     The visibility of an object to the human eye generally depends on the size of the object, the relative distance between the object and the observer, the relative speed of the object, the color of the object, and the light intensity and atmospheric conditions. The human brain and eye refresh images approximately every 0.1 seconds, while the average shot flight time to the target ranges from approximately 0.05 to 0.3 seconds; this makes shooting moving objects a real challenge. 
     Inventors have developed tracers for shotgun shells in an attempt to aid the shooter in visualizing his or her shot with regard to the target. Prior inventions can be categorized as non-ignition and ignition type tracers. Each type has its limitations, including the risk of fire with pyrotechnic tracers and the complexity of manufacturing in the case of chemiluminescent tracers. Both types share a significant drawback: the fact that the shooter has a mere fraction of the second to see the tracer. This makes current inventions of limited value to shooters in providing a consistent and visible reference to aid them in correcting their shooting. 
     The prior art includes the following inventions:
     1. Shot-Shell (U.S. Pat. No. 1,304,962 to J. Gravely in 1919);   2. Shotgun Shell (U.S. Pat. No. 1,457,337 to E. Barrows in 1923);   3. Method and Apparatus for Forming Letters and Symbols in the Air (U.S. Pat. No. 1,716,794 to J. Remey, 1929);   4. Shotgun Cartridge (U.S. Pat. No. 1,887,990 to H. Brownsdon in 1932);   5. Artificial Production of Fog (U.S. Pat. No. 1,895,765 to U. Muller in 1933);   6. Method for Creating Aerial Effects (U.S. Pat. No. 2,062,511 to J. Haddock in 1936);   7. Tracer Shotshell (U.S. Pat. No. 3,262,390 to R. Cowles in 1966);   8. Apparatus for Producing Smoke or Fog (U.S. Pat. No. 3,244,641 to D. Durr in 1966);   9. Method and Means for Producing and Controlling the Discharge of Fog (U.S. Pat. No. 3,379,373 to R. Roberts in 1968);   10. Nebulizer (U.S. Pat. No. 3,652,015 to G. Beall in 1972);   11. Shotgun Shell Tracer Wad (U.S. Pat. No. 4,553,481 to V. Ricci in 1984);   12. Method and Apparatus for Sky Typing (U.S. Pat. No. 4,561,201 to G. Sanborn in 1985);   13. Efficient Artificial Smoke Generator (U.S. Pat. No. 4,836,452 to J. Fox in 1989);   14. Aerosol Diffusion Fogger (U.S. Pat. No. 5,057,243 to M. Becker in 1991);   15. Diffusion Fogger (U.S. Pat. No. 4,990,290 to J. Gill in 1991);   16. Tracer Cartridges (U.S. Pat. No. 5,429,054 to R. Topping in 1995);   17. Smoke Generator for Radio Controlled Aircraft (U.S. Pat. No. 5,932,978, to J. Geyer in 1999);   18. Compression Cartridge (U.S. Pat. No. 6,250,228 to F. King in 2003);   19. Shotgun Shell Flight Path Indicator (U.S. Pat. No. 6,539,873 to E. W. Diller in 2003);   20. Ballistic Tracer Platform for Shotgun Ammunition (U.S. Pat. No. 10,656,471 to J. Dunnam and M. Quintana in 2007 and U.S. Pat. No. 7,610,857 to J. Dunnam and M, Quintana in 2009).   

     An improved design would overcome the drawbacks of the prior art and would fulfill the following criteria:
         (a) Provide the shooter with a consistent and accurate reference to the target.   (b) Give the shooter more time to see the tracer with reference to the target; in other words the improved design should have memory.   (c) Be safe to use and environmentally friendly.   (d) Be simple and economical to manufacture.   (e) Be entertaining to the shooter.       

     SUMMARY OF INVENTION 
     The present invention provides an innovative design for a tracer that comprises a tracer cylinder that contains a liquid, which utilizes appropriate valves, and which, when loaded into a shotgun shell and fired, has the means to release the liquid and emit a thick and long-lasting mist or fog cloud that provides the shooter with a consistent and durable reference, allowing him or her to make effective corrections to his or her shooting technique. The invention uses any one of a variety of liquid compounds, such as a vegetable oil (like olive oil), mineral oil, synthetic oil, paints, water, aqueous gels, and known fogging liquids such as titanium tetrachloride (TiCl 4 ). When water or an aqueous gel is used, various dyes, pigments, and/or reflective particles are added in order to make the fog cloud more visible to the shooter. This invention can be modified and can be used with all shot types and in many shotgun gauges, including 8, 10, 12, 16, 20, 28 and 410. 
     In accordance with the present invention, the tracer comprises a cylinder with a length equal to or larger than its diameter, thereby ensuring its accuracy. Holding the liquid of choice, the cylinder is loaded into a typical shotgun shell, strategically located in front of the shot pellets in order to minimize the structural stresses on the cylinder resulting from ignition of the propellant. Alternatively, it can be loaded into the shot holder of a wad, with no shot pellets. In either case, the shot cup petals protect it during firing and acceleration of the wad and cylinder down the barrel. The cylinder can be sized to have different internal and exterior diameters and length combinations in order to adjust the volume of liquid, depending on the shotgun gauge with which it is used and other variables, such as the distance to the target and the size and type of shot. 
     The tracer cylinder has a disk-shaped top cap and a bottom container portion defining a cavity; the two parts are glued or welded together after the liquid has been injected into the cavity. A flat, disk-shaped piercing valve with a centrally-located point is positioned on top of the shot and below the tracer cylinder, with the end of the point adjacent to the bottom of the container portion of the tracer cylinder. The piercing valve has a diameter that is larger than that of the container, so that its edge extends past the outer circumference of the container. 
     Upon ignition of the shotgun shell and during acceleration of the tracer cylinder in the shotgun barrel, inertial forces push the point of the piercing valve into the bottom of the container portion of the tracer cylinder, creating a small, centrally-located opening in the bottom of the container. As the cylinder exits the barrel and is airborne, the edge of the piercing valve is affected by drag forces, which cause the displacement of the piercing valve, without affecting the accurate movement of the cylinder in front of the shot. The liquid inside the container is extracted through the opening created by the point of the piercing valve due to the difference in pressure between the liquid inside the cylinder and the low pressure air surrounding the sides and bottom portion of the cylinder created as the cylinder moves rapidly through the air. Upon exiting the cylinder through the opening in the bottom of the container, the miniature droplets of liquid create a mist or fog cloud, which is contained by the cone of air created at the rear of the cylinder, thereby increasing its density and making it visible for several seconds. This lasting fog cloud is visible to the eye in much the same way as a contrail or the tail of a comet, and it is easily seen by the shooter. The size of the opening created by the point on the piercing valve allows the manufacturer to adjust the amount of liquid being expelled from the cylinder, affecting the diameter, density and duration of the fog cloud created. 
     A metal ring-shaped weight can be affixed to the top cap of the tracer cylinder in order to increase its mass and to shift mechanical stressed on the cylinder during launch to the walls of the cylinder. 
     It is an object of the present invention to provide a tracer comprising a cylinder that contains a liquid which, after exiting the barrel of a shotgun, produces a mist or fog cloud that accurately traces the shot and is easily visible to the shooter for a sufficient amount of time so that it can be effectively used to help him or her with his or her shooting technique. 
     Another object of this invention is to provide the means by which the liquid contained in the cylinder can be released without negatively affecting the accuracy of the tracer. 
     Still another object of this invention is to provide a tracer comprising a cylinder filled with liquid which, after exiting the barrel, produces a fog cloud similar to that of a comet trail or contrail, the invention providing the means to adjust the diameter and length of the cylinder, as well as the density and duration of the tracing effect, depending on the gauge of the shotgun shell and the application with which it is to be used. 
     A further object of this invention is to provide a tracer for shotgun ammunition, the device being accurate and safe to use in single barrel, double barrel and semi-automatic shotguns, and, further, being structurally sound and able to withstand the high structural stresses associated with its application. 
     Further objects and advantages of this invention will become apparent from a consideration of the drawings and description, infra. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of a shotgun shell containing the tracer cylinder of the present invention. 
         FIG. 2  is a sectional side view of the shell of  FIG. 1 , taken along line  2 - 2 , showing the tracer cylinder strategically positioned in the shotgun shell, in front of the shot. 
         FIG. 3  is an isometric view of an alternative shotgun shell containing the tracer cylinder of the present invention. 
         FIG. 4  is a sectional side view of the alternative shotgun shell containing the tracer cylinder illustrated in  FIG. 3  taken along line  4 - 4 . 
         FIG. 5  is an enlarged cross-sectional view of the top of the alternative shotgun shell containing the tracer cylinder illustrated in  FIG. 4  taken along line  5 - 5 . 
         FIG. 6  is an enlarged cross-sectional view of wad inside of the alternative shotgun shell containing the tracer cylinder illustrated in  FIG. 4  taken along line  6 - 6 . 
         FIG. 7  is a sectional side view of an empty tracer cylinder. 
         FIG. 8  is a sectional side view of a tracer cylinder containing tracer liquid, which is positioned above a disk-shaped piercing valve. 
         FIG. 9  is a sectional side view of a tracer cylinder containing tracer liquid, after the bottom of the cylinder has been punctured by the disk-shaped piercing valve. 
         FIG. 10  shows a sectional side view of an airborne tracer cylinder after the shell has been fired from a shotgun, the disk-shaped piercing valve having fallen away due to air drag forces, the liquid being released into the atmosphere by the vacuum created in the air surrounding the tracer cylinder. 
         FIG. 11  is a top view of an alternate embodiment of the present invention, showing a ring-shaped weight affixed to the top cap of the tracer cylinder. 
         FIG. 12  is a side view of the alternate embodiment, showing the ring-shaped washer affixed to the top cap of the tracer cylinder. 
         FIGS. 13A through 13D  are sequential sectional side views of the tracer cylinder before and after ignition of the shell, showing the piercing of the tracer cylinder, the detachment of the valve, and the release of the liquid from the tracer cylinder. 
         FIG. 14  is a representational view of a shooter using the tracer cylinder of the present invention while shooting at a clay target. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is designed to be used in a typical shotgun shell  1 , which generally has a hull  2  with a metal base cap  3  and a crimped top  4 , as shown in  FIG. 1 . 
     The sectional view in  FIG. 2  shows the shotgun shell  1  with hull  2  and base cap  3 , which has been assembled to hold the tracer cylinder  5  containing the tracer liquid  6 , which is positioned in front of or on top of the shot pellets  7 , separated therefrom and protected by a disk-shaped piercing valve  8  with a centrally-located perpendicular point  18 , made of metal, hard plastic, or a similar rigid material. The shot pellets  7  are enclosed in a shot cup  9 , which incorporates a gas seal  10  that is in direct contact with the propellant  11 , which is next to the primer  12  at the lower end of the shotgun shell  1 . The cylinder  5  consists of a top cap  13  with a radial indentation  14  and a container portion  15 . The radial indentation  14 , or step, provides more contact surface for glueing or welding the cap  13  to the container portion  15 . It also permits easier and more accurate alignment of the two parts. The tracer liquid  6  used can be any one of a variety of liquid compounds, such as a vegetable oil (like olive oil), mineral oil, synthetic oil, paint, water, and aqueous gels, as well as known fogging liquids such as titanium tetrachloride (TiCl 4 ). When water or an aqueous gel is used, various dyes, pigments, and/or reflective particles are added in order to make the fog cloud more visible to the shooter. The bottom  16  of the container portion  15  is symmetrically positioned above the point  18  on the disk-shaped piercing valve  8  that has an outer edge  19  extending past the cylindrical sidewall  20  of the container portion  15 . 
     In order to manually assemble the piercing valve  8  and tracer cylinder  5  into the shotgun shell  1 , a user can insert the piercing valve  8 , point-side up, above the shot pellets  7  and then drop the tracer cylinder  5 , bottom-side down, on top of it. The height from which the tracer cylinder  5  is dropped must not be more than the height from which the tracer cylinder  5  has enough kinetic energy to be punctured by the point  18  on the piercing valve  8  during assembly. If an automated high volume manufacturing process is used, the same care must be taken to avoid puncturing the bottom  16  of the tracer cylinder  5  during the assembly process. Alternatively, the piercing valve  8  can be made as an integral component of the tracer cylinder  5  in the injection molding process used to form the top cap  13  and container  15 . In this case, the piercing valve  8  could be attached by small plastic columns to the bottom  16  of the tracer cylinder  5 , which guarantees that the point  18  on the piercing valve  8  is centrally positioned to the bottom  16  of the tracer cylinder  5 . Connecting the piercing valve  8  and the tracer cylinder  5  allows the components to be assembled in the shotgun shell  1  as a single unit, which greatly benefits high volume processes. The position and number of such connecting columns will vary, but they should be located symmetrically. Upon firing of the shotgun shell  1 , inertial forces would buckle and break the connecting columns, allowing the point  18  of the piercing valve  8  to puncture the bottom  16  of the tracer cylinder  5 . 
     The space between the cylindrical sidewall  20  of the container portion  15  and the shot cup  9  is typically filled, either by using a shot cup  9  with petals having thickened upper portions, or by inserting a resilient spacer. 
     Shown in  FIG. 3  is an alternative shotgun shell  21 , which generally has a hull  2  with a metal base cap  3  and a crimped top  4 . 
     As shown in  FIG. 4 , when used with the alternative shotgun shell  21 , a disk-shaped piercing valve  8  with a centrally-located perpendicular point  18 , made of metal, hard plastic, or a similar rigid material and a tracer cylinder  5 , with container portion  15  holding tracer liquid  6 , can be loaded into a conventional wad without any shot pellets, particularly when a shooter wishes to fire it merely as an indicator or reference. When this embodiment is assembled, a cylindrical wad  22 , made from polypropylene, polyethylene, or another high-strength plastic, is placed inside the hull  2  of the shell  21  above the propellant  11  inside base cap  2 . The wad  22  is typically formed with shock-absorbing compression columns  23   a ,  23   b , ( 23   c ,  23   d ) and has a gas seal  24  formed in its lower end. The tracer cylinder  5  is then placed into the wad shot holder  25 , inside the petals  26   a ,  26   b , ( 26   c ,  26   d ), which surround the sidewall  20  and cushion the tracer cylinder  5  during ignition, and which open and fall away when the tracer cylinder  5  is in flight. Like the tracer cylinder  5  shown in  FIG. 2 , the bottom  16  of the container portion  15  is symmetrically positioned above the point  18  on the disk-shaped piercing valve  8 . Assembly of the piercing valve  8  and the cylinder  5  into the shell  21  are performed as described supra, in the description related to  FIG. 2 . 
       FIG. 5  shows the sidewall  20  of the container  15  inside the petals  26   a ,  26   b ,  26   c ,  26   d  of the shot holder  25  inside the hull  2 . The container portion  15 , which has been filled with tracer liquid  6 , has been positioned above the point ( 18 ) on the disk-shaped piercing valve  8 , whose outer edge  19  extends past the sidewall  20  of the container portion  15 . 
       FIG. 6  shows the shock-absorbing compression columns  23   a ,  23   b ,  23   c ,  23   d  of the wad  22  inside the hull  2 , as well as the gas seal  24 . 
       FIG. 7  shows a sectional view of an empty tracer cylinder  5 , consisting of a disk-shaped top cap  13  with radial indentation  14  and a cylindrical container portion  15 , which will be glued or welded together, leaving a cavity  30 . Both parts of the tracer cylinder  5  are typically made from a high-strength plastic, such as polypropylene or polyethylene, or from nylon, using standard high volume processes, including injection molding and high-speed screw machines. Alternatively, the top cap  13  and container portion  15  can be made from a metal, such as brass, aluminum, copper or steel, using stamping and deep drawing techniques. After the tracer liquid  6  has been injected into the cavity  30 , the top cap  13  and the container portion  15  will be joined together. The joining process can be performed in a number of ways, such as using a combination of specialized high strength glues and accelerators, soldering, or welding, including ultrasonic welding. 
       FIG. 8  is a sectional view of the tracer cylinder  5  after it has been filled with tracer liquid  6 . The tracer liquid  6  has been loaded into the cylinder  5  at atmospheric pressure or at a slightly higher pressure to aid in the flow of the tracer liquid  6  out of the tracer cylinder  5 , depending on the type of shell  1  used and the distance to the target. The bottom  16  of the filled tracer cylinder  5  will be positioned above a disk-shaped piercing valve  8 , which generally has a diameter that is slightly larger than the diameter of the cylinder  5  so that its outer edge  19  extends past the sidewall  20  of the container portion  15 . The disk-shaped piercing valve  8  can be made from metal, hard plastic, or a similar rigid material, using standard injection molding and stamping processes. The disk-shaped piercing valve  8  has a centrally-located cone-shaped point  18 , which is somewhat longer that the thickness of the bottom  16  of the container portion  15  so that the point  18  can properly puncture the bottom  16 . The diameter of the point  18  must be small enough to form an opening that permits proper mystification of the tracer liquid  6  during flight (see next paragraph). 
       FIG. 9  shows a sectional view of the tracer cylinder  5  after the point  18  of the disk-shaped piercing valve  8  has punctured the bottom  16  of the container portion  15  of the tracer cylinder  5 , forming opening  17  and coming in contact with the tracer liquid  6 . The size of the opening  17  formed will range from approximately 0.5% to 5% of the diameter of the cylinder  5 , depending on the speed at which the cylinder  5  will travel and the type and viscosity of the liquid  6  used as a tracer. The opening  17  needs to be small enough to extract minute droplets of liquid  6  in order to create a mist or fog cloud upon exiting the cylinder  5 , yet large enough to allow the liquid  6  to flow out of the cylinder  5  due to the difference in pressure exerted on the liquid  6  inside the cylinder  5  and the low pressure air surrounding the sides and bottom portion of the cylinder  5 . As can been seen in the figure, the diameter of the piercing valve  8  is greater than the outer diameter of the cylinder  5 , with outer edge  19  extending beyond the sidewall  20  of the cylinder  5 . 
       FIG. 10  shows a sectional view of the tracer cylinder  5  of  FIG. 9  after the shotgun shell ( 1  or  21 ) has been fired and the cylinder  5  has left the barrel. The disk-shaped piercing valve  8  has been detached due to strong air drag forces exerted on its edge  19  after the tracer cylinder  5  is airborne. Because the disk-shaped piercing valve  8  was symmetrically positioned on the bottom  16  of the container portion  15 , it separates without affecting the accuracy of the device. After the piercing valve  8  has been removed, the tracer liquid  6  in the tracer cylinder  5  is released into the atmosphere through the opening  17  in the bottom  16  of the container portion  15  due to the low-pressure area surrounding the cylinder  5  in flight. 
     The tracer liquid  6  exits through the small opening  17  in the form of small droplets  32 , which create a fog mist or cloud  52  that is highly visible to the shooter (i.e., the sunlight reflects off the increased surface area of the droplets). Because only small droplets  32  are released from the cylinder  5 , the amount of tracer liquid  6  the cylinder  5  must hold can be very small and, therefore, the device is extremely efficient. Because the tracer liquid  6  exits the cylinder  5  through the opening  17  in the bottom  16  of the container  15 , the fog cloud created is contained within the cone of air created by the air stream at the back of the cylinder  5 , thereby increasing its density and making it visible for several seconds. This long-lasting fog cloud mimics the tail of a comet and is easily seen by the shooter. 
     As shown in  FIG. 11 , tracer cylinder  5  of the present invention can be made with a ring-shaped weight  33  affixed to its top cap  13 . The main purpose of the ring-shaped weight  33  is to increase the mass of the cylinder  5  during launch. The geometry of the ring-shaped weight  33  shifts the mechanical stresses on the cylinder  5  during launch from its nose to its cylindrical walls. The ring-shaped weight  33  is typically be made from metal, such as aluminum, copper, brass, bronze, lead, or steel. Its outer diameter is smaller than the outer diameter of the cylinder  5  to avoid direct contact with the gun barrel. The diameter of the ring-shaped weight  33 , its thickness, and the size of the central opening will vary, depending on the material used to make the ring-shaped weight  33  and the cylinder&#39;s  5  range or application. 
       FIGS. 12A and 12B  are side views of the tracer cylinder  5  shown in  FIG. 11 , showing the ring-shaped weight  33  affixed to the top cap  13  of the tracer cylinder  5  with a layer  34  of adhesive or high-strength glue, or by ultrasonic welding. The weight  33  can be made from a metal, such as lead, aluminum, brass, steel, copper, or bronze. 
     In  FIG. 12A , the ring-shaped weight  33  has simply been affixed onto the upper side of the top cap  13 . As shown in  FIG. 12B , the ring-shaped weight  33  can be affixed or snap-fitted to the top cap  13  inside a radial indentation  35  formed in the top cap  13  or it can be integrated into the cap  13  during injection molding of the cap  13 . The radial indentation  35  adds mechanical interference and increases the surface area for the glue, if used. 
       FIGS. 13A-13D  show the typical movement of the tracer cylinder  5  before and after ignition of the shotgun shell  1 . 
     In  FIG. 13A , the shotgun shell  1 , containing a shot cup  9  with shot pellets  7 , a disk-shaped piercing valve  8 , and a cylinder  5  holding tracer liquid  6 , has been loaded into the shotgun barrel  50 . The bottom  16  of the container portion  15  of the cylinder  5  has been positioned in front of the piercing valve  8 . The primer  12  ignites the propellant  11 , and gasses expand into the gas seal cavity  10 . 
     In  FIG. 13B , the expanding gases  51  of ignition propel the shot cup  9  with shot pellets  7  and the cylinder  5  holding the tracer liquid  6  through the shotgun barrel  50 . The forces of ignition have caused the point  18  on the piercing valve  8  to puncture the bottom  16  of the container portion  15  of the cylinder  5  holding the tracer liquid  6 . 
     In  FIG. 13C , after leaving the shotgun barrel  50 , the shot cup  9  has flipped out of the way of the scattering shot pellets  7 . The disk-shaped piercing valve  8  has been detached, and the cylinder  5  continues to travel in front of the pattern of shot pellets  7 . 
     As shown in  FIG. 13D , the tracer liquid  6  is being drawn from the opening  17  in the bottom of the cylinder  5 , creating a fog cloud  52 , which coincides with the pattern of shot pellets  7 . 
       FIG. 14  shows a shooter  55  using the tracer cylinder  5  of the present invention. The shooter  55  has loaded his shotgun barrel  50  with the shotgun shell ( 1  or  21 ), as he would load any other ammunition. The shooter  55  has aimed at the clay target  60  and has fired. The cylinder  5  has left the shotgun barrel  50 , in front of the shot string  56   a ,  56   b ,  56   c ,  56   d , leaving a fog cloud  52  streaming through the center of the expanding pattern of shot pellets in the shot string  56 . The shot cup  9  has flipped out of the way. If the shooter  55  hits the clay target  60 , it breaks into pieces  61 . If he misses the clay target  60 , the shooter  55  would correct his lead or aiming point, according to the relative position of the fog cloud to the clay target  60 . 
     The information in the disclosure and description of the invention itself are illustrative only of the application of the principles of the present invention. Modifications and alternative embodiments may be devised by those skilled in the art without departing from the spirit and scope of the present invention. For instance, the tracer cylinder can be enclosed in an annular cylinder made of plastic, cardboard or paper, to accommodate the use and production of a standardized tracer device that can be used in different shotgun gauges. Further, the bottom  16  of the container portion  15  can be made with a centrally-located indentation or notch that would engage the point  18  of the disk-shaped piercing valve  8  and facilitate the puncturing of the bottom  16  of the container portion  15  during launch of the shell  1 .