SUB-SONIC BULLET CASING

Abstract

The invention involves a cartridge case and ammunition that can provide multiple projectile speeds from a single cartridge case. The cartridge case includes an insert that may be molded to or inserted within the cartridge case to allow for variable powder loads. The variable powder loads provide the user with the ability to load cartridge cases for different projectile velocities, including sub-sonic, while still providing sufficient fill inside the cartridge case for desired powder burn rate; the proper and desired burn rate of the powder providing proper breech and barrel pressures for the desired projectile velocity. The cartridge cases are constructed to be loaded with standard and pre-existing loading tools and are reloadable.

Description

PRIORITY CLAIM

In accordance with 37 C.F.R. 1.76, a claim of priority is included in an Application Data Sheet filed concurrently herewith. Accordingly, the present invention claims priority to U.S. Provisional Patent Application No. 63/767,520, entitled "SUB- SONIC BULLET CASING", filed March 5, 2025. The contents of the above referenced application are incorporated herein by reference in their entirety.

FIELD OF INVENTION

The present invention generally relates to firearm ammunition, and more particularly, to a bullet casing constructed to be substantially filled with powder and capable of firing a bullet at sub-sonic speeds.

BACKGROUND INFORMATION

In the world of firearms, the significance of cartridge cases cannot be overstated. These small but critical components play a pivotal role in the operation and effectiveness of firearms. Cartridge cases, often referred to simply as "case or casing" in the context of firearms, are the cylindrical, metallic containers that house the ammunition used in firearms. These cases are made from various materials, with brass, aluminum, and steel being the most common choices. They include several components, including the casing itself, the case head, the case mouth, and the primer pocket. Each of these elements serves a specific function in the firing and extraction of the case. The casing is typically made of brass and serves as the outer shell of the cartridge. It holds the components of the bullet in the proper operational location and orientation, and is responsible for sealing the chamber of the firearm during ignition of the powder. Brass is favored for the case due to its ability to expand and seal the chamber effectively when fired, preventing gas leakage and ensuring safe operation of the firearm. Brass also serves to reduce wear and damage to the firearm because it is relatively soft compared to firearm components. The primer is a small explosive device that, when struck by the firing pin, ignites and initiates the ignition of the propellant inside the case. The primer pocket is a small recess in the base of the cartridge case where the primer is seated to cause the powder to burn from the rear of the casing to the front of the casing, creating the air pressure required to expel the bullet or projectile from the casing. The case head is the base of the cartridge case, and it is where the primer pocket is located. It is this part of the case that interfaces with the firearm's breech face. The case mouth is the open end of the cartridge case, and it is where the bullet (projectile) is seated. It plays a crucial role in guiding the bullet into the bore of the barrel for accurate firing.

Cartridge cases are integral to the functioning of a firearm in multiple ways. Cartridge cases are designed to withstand the high pressures generated during firing. Their strength and durability are crucial for ensuring the safety and reliability of firearms. A well-manufactured cartridge case prevents catastrophic failures, such as ruptures or blowbacks, which could cause serious harm to the shooter. Consistency in cartridge case dimensions and quality is essential for maintaining accuracy in shooting. Inaccurate or poorly manufactured cases can lead to variations in bullet trajectory and impact point, affecting the shooter's ability to hit their target. After firing, the cartridge case must be efficiently extracted from the firearm's chamber and ejected from the weapon to make way for the next round. Cartridge cases with appropriate dimensions and materials ensure smooth extraction and ejection, contributing to the firearm's reliability and rate of fire. Many shooters and enthusiasts engage in reloading their ammunition. Cartridge cases play a crucial role in this process. High-quality cases, designed for multiple reloads, reduce the overall cost of shooting and contribute to a sustainable and eco-friendly approach to firearm use.

One drawback to standard cartridge case designs is the requirement that the casing be mostly filled with powder to provide the proper burn rate of the powder to create a reliable and consistent pressure for expelling the bullet from the firearm. Small differences in burn rates alter the pressure curve created by the expanding gases and thus cause inconsistencies in bullet speeds and bullet accuracies. When most cartridge cases are sufficiently filled to provide the proper burn rate, the bullet is typically propelled at velocities that are above the speed of sound. This increases the noise created by firing the ammunition. While the weight of the bullet can be altered to affect speed, this is not always the desired method of changing the velocity of the projectile. Projectile weight affects flight trajectory and impact force. Thus, while the bullet may be slower, it may not have the desired trajectory or impact. It is also desirable to create bullets with different speeds having the same caliber (diameter). For example, when a sound suppressor is used on a firearm, sub-sonic speeds are desirable to prevent the sonic boom from the projectile to maintain the suppressed sound. Thus, there exists a need in the art for a cartridge case that can be utilized to construct ammunition having different speeds while still utilizing the same cartridge case. The speeds should range from supersonic to sub-sonic. The cartridge cases should be reloadable and should fit the firearm as a standard cartridge case. The cartridge cases should be loadable and reloadable using standard tooling.

Thus, the present invention provides a cartridge case for a firearm which overcomes the disadvantages of prior art. The cartridge case of the present invention not only provides for relative ease in tailoring the speed of the projectile (bullet) in flight, it also provides a cartridge case suitable for sub-sonic loads at predictable burn rates. Still yet, the present cartridge case can be loaded and reloaded using standard reloading tools.

SUMMARY OF THE INVENTION

Briefly, the invention involves a cartridge case and ammunition that can provide multiple projectile speeds from a single cartridge case. The cartridge case includes an insert that may be molded to or inserted within the cartridge case to allow for variable powder loads. The variable powder loads provide the user with the ability to load cartridge cases for different speeds, including sub-sonic, while still providing sufficient fill inside the cartridge case for desired powder burn rate, providing proper breech and barrel pressures for the desired projectile velocity. The cartridge cases are constructed to be loaded with standard and pre-existing loading tools and are reloadable.

Accordingly, it is an objective of the present invention to provide a cartridge case that includes standard outside dimensions and an internal cavity with reduced fill volume.

It is a further objective of the present invention to provide a cartridge case for sub-sonic projectile velocities.

It is yet a further objective of the present invention to provide a system for modifying a pre-existing cartridge case for reduced powder volume for modifying projectile speed.

It is another objective of the present invention to provide a polymeric fill adapter to modify the fill of the cartridge case.

It is yet another objective of the present invention to provide a polymeric fill adapter to modify the shape of the powder filling the cartridge case for desired burn characteristics.

It is still yet another objective of the present invention to provide a sub-sonic cartridge case that can be reloaded.

It is yet a further objective of the present invention to provide a fully molded polymer cartridge case. It is still yet another objective of the present invention to provide a fully molded polymeric cartridge case having a reduced internal volume.

Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification, include exemplary embodiments of the present invention, and illustrate various objects and features thereof.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side view of a cartridge casing for constructing firearm ammunition; FIG. 2 is a section view, taken along lines 2-2 of FIG. 1, illustrating the powder fill adapter of the present invention;

FIG. 3 is a side view of a cartridge casing for constructing firearm ammunition; FIG. 4 is a section view, taken along lines 4-4 of FIG. 3, illustrating the powder fill adapter of the present invention;

FIG. 5 is a side view of a cartridge casing for constructing firearm ammunition; FIG. 6 is a section view, taken along lines 6-6 of FIG. 5, illustrating the powder fill adapter of the present invention;

FIG. 7 is a side view of a cartridge casing for constructing firearm ammunition; FIG. 8 is a section view, taken along lines 8-8 of FIG. 7, illustrating the powder fill adapter of the present invention;

FIG. 9 is a side view of a cartridge casing for constructing firearm ammunition;

FIG. 10 is a section view, taken along lines 10-10 of FIG. 9, illustrating the powder fill adapter of the present invention;

FIG. 11 is a side view of a cartridge casing for constructing firearm ammunition;

FIG. 12 is a section view, taken along lines 12-12 of FIG. 11, illustrating the powder fill adapter of the present invention;

FIG. 13 is a side view of a cartridge casing for constructing firearm ammunition;

FIG. 14 is a section view, taken along lines 14-14 of FIG. 13, illustrating the powder fill adapter of the present invention;

FIG. 15 is a side view of a cartridge casing for constructing firearm ammunition;

FIG. 16 is a section view, taken along lines 16-16 of FIG. 15, illustrating the powder fill adapter of the present invention;

FIG. 17 is a side view of a cartridge casing for constructing firearm ammunition;

FIG. 18 is a section view, taken along lines 18-18 of FIG. 17, illustrating the powder fill adapter of the present invention;

FIG. 19 is a side view of a cartridge casing for constructing firearm ammunition;

FIG. 20 is a section view, taken along lines 20-20 of FIG. 19, illustrating the powder fill adapter of the present invention;

FIG. 21 is a side view of a cartridge casing for constructing firearm ammunition;

FIG. 22 is a section view, taken along lines 22-22 of FIG. 21, illustrating the powder fill adapter of the present invention;

FIG. 23 is a side view of a cartridge casing for constructing firearm ammunition;

FIG. 24 is a section view, taken along lines 24-24 of FIG. 23, illustrating the powder fill adapter of the present invention;

FIG. 25 is a side view of a cartridge casing for constructing firearm ammunition;

FIG. 26 is a section view, taken along lines 26-26 of FIG. 25, illustrating the propellant (powder) fill adapter of the present invention;

FIG. 27 is a side view of a single round of ammunition including the present invention; and FIG. 28 is a section view, taken along lines 28-28 of FIG. 27, illustrating the propellant filled propellant fill adapter and a projectile.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated.

Referring generally to the figures, a cartridge case 10 for constructing firearm ammunition 100 having reduced internal volume for propellant (powder) is illustrated. The cartridge case 10 includes a case head 12, the case head 12 including a primer pocket 14, a cartridge case wall 16 integrally formed to the case head 12, the cartridge case wall 16 being tubular in construction and extending between the case head 12 and a shoulder portion 18 which reduces the diameter of the cartridge case wall 16 while still maintaining the tubular shape, the shoulder portion 18 transitioning to a neck portion 20 integrally formed to the shoulder portion 18. The neck portion 20 maintains the tubular construction and extends substantially parallel with respect to the cartridge case wall 16, terminating in a cartridge case mouth 22 for accepting and locating a bullet assembly, the cartridge case 10 defining a propellant chamber 24 including an inner surface defining a first volume, a propellant fill adapter 28 positioned within the propellant chamber 24 for reducing the volume of propellant that will fit into the cartridge case 10 defining a second volume.

In the preferred embodiment, the cartridge is constructed from a metal, such as brass or cartridge brass; other embodiments may utilize aluminum, steel, titanium, and suitable polymers. In the case of polymer cartridge cases, the cases should be constructed of a polymer suitable for containing the pressures and heat utilized for discharge of a sub-sonic bullet. Suitable polymers may include, but should not be limited to polycarbonate (PC), polyetheretherketone (PEEK) polyaryletherketone (PAEK), polyetherketone (PEK), polyether-ketoneketone (PEKK), polythalamide (PPA), polyphenylene sulfide (PPS), polysulfone (PSU), polyethersulfone (PES), Ultem and the like, as well as suitable combinations thereof. The polymers may be glass filled, carbon filled and/or bearing grade without departing from the scope of the invention. It should also be noted that coatings such as copper or brass may be applied to at least the outer surface of the cartridge cases including the polymer cartridge cases. In a preferred embodiment, the propellant fill adapter 28 is constructed from a polymer, resin or plastic suitable to withstand the pressure and heat from ignition of the propellant at least once, and more preferably multiple firings with respect to the same cartridge case. Suitable polymers may include, but should not be limited to polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), acrylic or polymethyl methacrylate (PMMA), polycarbonate (PC), polyetheretherketone (PEEK) polyaryletherketone (PAEK) polyetherketone (PEK), polyetherketoneketone (PEKK), polythalamide (PPA), polyphenylene sulfide (PPS), polysulfone (PSU), polyethersulfone (PES), Ultem and the like, as well as suitable combinations thereof. It should also be noted that the polymer(s) may include fillers, such as fiberglass, carbon fiber or the like, without departing from the scope of the invention. It should also be noted that while polymers are the preferred material for the fill adapter, other materials such as metals, wood, phenolics, resins and suitable combinations thereof may be utilized without departing from the scope of the invention so long as the material has suitable strength to displace the interior volume of the cartridge case before firing. The fill adapter may be constructed to stay in position within the cartridge case or it may be constructed fragment, or simply be ejected after the projectile when the cartridge is fired.

Still referring generally to the figures, the propellant fill adapter 28 is generally constructed as a tubular member having an inner surface 30, an outer surface 32, a base end surface 34, and a mouth end surface 36. In one embodiment, the outer surface 32 is constructed and arranged to conform to the inner surface 26 of the propellant chamber 24 from the base end surface 34 to the mouth end surface 36. In this manner, the propellant fill adapter 28 is supported by the cartridge case 10 during firing of the ammunition. This significantly reduces the force that the propellant fill adapter 28 is required to withstand without breaking apart or being ejected with the projectile through the barrel of the firearm. In other embodiments, FIGS. 5-10, the outer surface 32 of the propellant fill adapter 28 is constructed and arranged to be spaced away from the inner surface 26 of the propellant chamber 24 along the full length of the propellant fill adapter 28 with the exception of the base end surface 34 and the mouth end surfaces 36, which contact the inner surface 26 of the propellant chamber 24 to prevent propellant from getting between the outer surface 32 and the inner surface 26. This construction allows the propellant fill adapter 28 to expand when the propellant is ignited and contract after firing. It should also be noted that some embodiments include more space at the base end surface 34, while others include more space at the mouth end surface 36.

Still referring generally to the figures, the propellant fill adapter 28 may include various internal shapes constructed and arranged to control the burn rate of the propellant. Propellant comes in many shapes, as well as formulations, most of which have different burn characteristics. Powder shapes include, but should not be limited to, ball, sheet, strip, cord, pellet, single perforated pellet, multi-perforated pellet, and rosette. Thus, the inner surface 30 of the propellant fill adapter 28 accommodates the different propellants to allow the propellant burn to be manipulated to cause a desired pressure at a desired time within the firearm breach and barrel to accurately and reliably discharge the projectile. Thus, in some embodiments, FIGS. 4, 6, 8, 10, 16, 24 and 26, the inner surface 30 of the propellant fill adapter 28 is constructed and arranged to include a first cylindrical portion 38 extending from the base end surface 34 to the mouth end surface 36. In other embodiments, FIGS. 2, 14, 18, 20, 22, the inner surface 30 of the propellant fill adapter 28 is constructed and arranged to include a first cylindrical portion 38 extending from the base end surface 34 transitioning to a first frustoconical portion 40, which may transition to another shape or may extend to the mouth end surface 36. As shown in FIGS. 2, 14, 18, 20 and 22, the inner surface 30 of the propellant fill adapter 28 is constructed and arranged to include a first cylindrical portion 38 extending from the base end surface 34 transitioning to a first frustoconical portion 40, the first frustoconical portion 40 transitioning to a second cylindrical portion 42 extending toward the mouth end surface 36. While in still other embodiments, FIGS. 20, 22, the inner surface 30 of the propellant fill adapter 28 is constructed and arranged to include a first cylindrical portion 38 extending from the base end surface 34 transitioning to a first frustoconical portion 40, the first frustoconical portion 40 transitioning to a second cylindrical portion 42, the second cylindrical portion 42 transitioning to a second frustoconical portion 44, the second frustoconical portion 44 transitioning to a third cylindrical portion 46 and extending to the mouth end surface 36. In still other embodiments, FIG. 24, the propellant fill adapter 28 is crimped into position with the cartridge case 10. Thus, the propellant fill adapter 28 may be inserted into the cartridge case 10 during forming of the cartridge case 10 before the shoulder and neck portions 18, 20 are formed. This construction interlocks the cartridge case 10 and the propellant fill adapter 28. In yet another embodiment, FIG. 26, the propellant fill adapter 28 is constructed to float axially or radially within the propellant chamber 24. It should be noted that in all of the embodiments, the diameter and length of the cylindrical and frustoconical shapes may be adjusted as desired to cause the desired burn and resulting pressure of the propellant without departing from the scope of the invention.

Referring generally to the figures and more specifically to FIGS. 27 and 28, a loaded cartridge case 10 is illustrated. The loaded cartridge case 10 includes the propellant fill adapter 28 filled with propellant 50, a primer 52 for igniting the propellant, and a projectile 54 assembly.

It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention, and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.

One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary, and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention, which are obvious to those skilled in the art, are intended to be within the scope of the following claims.

Claims

1. A cartridge case for a firearm having reduced internal volume comprising:

the cartridge case including a case head, the case head including a primer pocket, a cartridge case wall integrally formed to the case head, the cartridge case wall being tubular in construction, the cartridge case wall extending between the case head and a shoulder portion which reduces the diameter of the cartridge case wall while still maintaining the tubular shape, the shoulder portion transitioning to a neck portion integrally formed to the shoulder, the neck portion maintaining the tubular construction and extending substantially parallel to the cartridge case wall, terminating in a cartridge case mouth for accepting and locating a bullet assembly, the cartridge case defining a propellant chamber including an inner surface defining a first volume, a propellant fill adapter positioned within the propellant chamber for reducing the volume of propellant that will fit into the cartridge case defining a second volume.

2. The cartridge case for a firearm having reduced internal volume of claim 1, wherein the propellant fill adapter is constructed from a polymer.

3. The cartridge case for a firearm having reduced internal volume of claim 2 wherein the propellant fill adapter is constructed as a tubular member having an inner surface, an outer surface, a base end surface, and a mouth end surface.

4. The cartridge case for a firearm having reduced internal volume of claim 3, wherein the outer surface is constructed and arranged to conform to the inner surface of the propellant chamber from the base end surface to the mouth end surface.

5. The cartridge case for a firearm having reduced internal volume of claim 4, wherein the inner surface of the propellant fill adapter is constructed and arranged to include a first cylindrical portion extending from the base end surface to the mouth end surface.

6. The cartridge case for a firearm having reduced internal volume of claim 4, wherein the inner surface of the propellant fill adapter is constructed and arranged to include a first cylindrical portion extending from the base end surface transitioning to a first frustoconical portion extending to the mouth end surface.

7. The cartridge case for a firearm having reduced internal volume of claim 4, wherein the inner surface of the propellant fill adapter is constructed and arranged to include a first cylindrical portion extending from the base end surface transitioning to a first frustoconical portion, the first frustoconical portion transitioning to a second cylindrical portion extending to the mouth end surface.

8. The cartridge case for a firearm having reduced internal volume of claim 4, wherein the inner surface of the propellant fill adapter is constructed and arranged to include a first cylindrical portion extending from the base end surface transitioning to a first frustoconical portion, the first frustoconical portion transitioning to a second cylindrical portion, the second cylindrical portion transitioning to a second frustoconical portion, the second frustoconical portion transitioning to a third cylindrical portion and extending to the mouth end surface.

9. The cartridge case for a firearm having reduced internal volume of claim 3, wherein the outer surface of the propellant fill adapter is constructed and arranged to be spaced away from the inner surface of the propellant chamber along the full length of the propellant fill adapter.

10. The cartridge case for a firearm having reduced internal volume of claim 3, wherein the outer surface of the propellant fill adapter is constructed and arranged to be positioned against the inner surface of the propellant chamber spaced away from the inner surface of the propellant chamber at the case head and spaced away from the inner surface of the propellant chamber at the case shoulder.

11. The cartridge case for a firearm having reduced internal volume of claim 1 wherein the cartridge case is constructed from brass.

12. The cartridge case for a firearm having reduced internal volume of claim 1 wherein the cartridge case is constructed from steel.

13. The cartridge case for a firearm having reduced internal volume of claim 1 wherein the cartridge case is constructed from aluminum.

14. The cartridge case for a firearm having reduced internal volume of claim 1 wherein the cartridge case is constructed from polymer.