Patent Publication Number: US-9903676-B2

Title: Ammunition system and ammunition for firearms

Description:
This application claims domestic priority from U.S. provisional application 62/202,401, filed on Aug. 7, 2015. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to an ammunition system for firearms, and more particularly to an ammunition system for muzzleloader firearms, which allows the ammunition to have a predetermined amount of propellant charge encased in a housing along with a separate muzzleloader projectile that when combined with the encased propellant charge, presents an ammunition cartridge that is significantly different than the prior art. 
     2. Description of Related Art 
     Like most early firearms, the first rifles were muzzleloading firearms. A muzzleloader is any firearm into which the projectile and usually the propellant charge is loaded from the muzzle of the gun (i.e., from the forward, open end of the gun&#39;s barrel). This is distinct from the more popular modern designs of breech-loading firearms. There are generally three types of muzzleloading firearms: inline  209  primers and percussion, caplock, and flintlock muzzleloaders. Inline  209  primers and percussion muzzleloaders tend to look like most modern firearms. The inline and caplock muzzleloaders differ on where the nipple is attached. In an inline muzzleloader, the cap is in line with the hammer and the barrel. The inline has the nipple attached to the barrel at the breech and accessed by a bolt or break action. Also, the inline model has a removable breech plug, to facilitate cleaning. Caplock rifles have a side-mounted firing pin similar to the flintlock rifle, and operate and load in much the same way, but uses a more modern pre-loaded firing cap to fire the rifle. A flintlock style of muzzleloader dates back to the 17th century and features a flintlock mechanism that produces sparks when a piece of flint strikes its steel frizzen. 
     Loading a traditional black powder muzzleloader firearm generally involves a certain amount of complexity (as compared to the loading of modern firearms). For loose, granular powder such general steps include: a) making sure the rifle is not primed; b) making sure the rifle bore is clean of fouling and oil; c) setting a powder measure for a desired powder charge; d) pouring the powder into the measure and then into the muzzle of the rifle; and e) using a ramrod, pressing the bullet, such as a patched round ball, past the rifling and down the bore until it contacts the powder charge. 
     The ammunition used in muzzle loaded rifles has evolved from a projectile that is a round ball compressed in the muzzle end with a patch, to projectiles that have incorporated features of modern bullets. Within the latter category, bullet shaped projectiles can be further subdivided into those that are fired with a sabot (which replaces the patch), and projectiles that are lubricated slugs. A sabot is an encasing plastic cup that generally falls away from the projectile after it exits the gun. The sabot eliminates the need for a lubricating means and assures that there is a good seal between the projectile and the bore of the barrel. 
     Current muzzle loading ammunition comprises multiple parts that are combined together when loaded into a firearm. Because the various parts are separate, they are not sealed, and they use pyrotechnic materials such as black powder or black powder substitutes that tend to be hygroscopic (they tend to absorb moisture from their surroundings and in particular absorb water vapor from the atmosphere). As a result, their efficiency degrades overtime, and the propellant and resultant combustion products tend to corrode the firearm barrel and chamber. 
     A complete round of ammunition consists of all the components necessary for one firing of the gun. These normally include a projectile, the propellant or busting charge, and a primer that ignites the propellant. Other components such as cartridge case and fuse are also included. 
     For muzzleloading firearms, multiple ammunition components are loaded from the open end of the barrel. These multiple components include at least a propellant charge and projectile. The propellant charges comprise a predetermined amount of black powder, black powder substitutes, or smokeless gunpowder. The projectile typically comprises a bullet and a sabot. In some instances, the projectile and the propellant charge are inserted into the barrel as a unitary structure. Alternatively, the propellant charge is loaded separately from the projectile. In such instances, the propellant charge is loaded first into the barrel, followed by the sabot and the bullet. 
     Ammunition has evolved over the years, but some general terminology has remained constant, and the terms are used herein in their accepted fashion:
         1. a cartridge, is a single unit of ammunition; for a modern small arms cartridge this is the combination of a bullet, propellant, primer and cartridge case in a single unit. The cartridge case is generally cylindrical in shape and includes an internal lumen. A propellant is contained within the lumen of the cartridge case. Ignition of the propellant provides the energy that propels the saboted bullet at a target;   2. a “round” is a term synonymous with a fully loaded cartridge containing a projectile, propellant, primer and casing; and   3. a “fixed round” is a round of ammunition which when stored outside of the firearm chamber prior to loading the round, has the propellant and the bullet commonly engaged to each other by direct engagement.       

     Loading or charging propellants into muzzleloading guns has long presented problems. The propellant, either black powder or a substitute thereof, is normally handled in granular form (grains), with each charge being determined by measuring out a selected weight or volume of the propellant from a bulk supply, delivering it to the bore of the gun, placing a projectile in the bore, and seating the charge by ramrod into the breech. The charging of this propellant thus requires special tools and implements which must be carried to the field of use and kept readily available for re-loading. In addition, there is always the risk of improper measurement and spillage of loose powder. Other problems exist. It is difficult to obtain uniform powder compaction from load to load. It is difficult to re-load with speed and accuracy, and the use of smokeless powder, if not properly measured, could pose an additional risk. 
     Various forms of ammunition have been proposed for muzzle loading ammunition. Such ammunition over the years evolved from round ball projectiles to ammunition that has incorporated many of the features of modern bullets. For example, U.S. Pat. No. 7,726,245 issued on Jun. 1, 2010, titled “MUZZLELOADER AMMUNITION,” teaches a fixed round of ammunition for a muzzleloader firearm. The round has a bullet within a sabot that is engaged to a consumable cartridge case. The case is filled with propellant. The bullet is engaged to the propellant composition via the cartridge case. This “fixed round” attempts to incorporate fully modern bullet attributes. In contrast, the more typical muzzle loading ammunition comprises multiple parts which are combined together when loaded into a firearm. 
     SUMMARY OF THE INVENTION 
     Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a case used to hold the propellant charge, and protect the charge from moisture absorption. 
     It is another object of the present invention to provide a bullet that is separate from the propellant charge case, but interacts with the charge case after ignition to have the combination be responsive to the rifling. 
     The above and other objects, which will be apparent to those skilled in the art, are achieved in the present invention which is directed to an ammunition for a firearm having a barrel with a breech end and a muzzle end, the ammunition comprising: a projectile; a casing having a forward end and a back end, the casing including: a cap at the forward end for sealing a propellant charge within the casing; a rim at the back end in mechanical communication with the firearm barrel breech end when the casing is inserted within the barrel; and a primer situated at the casing back end and responsive to a firing pin; wherein the projectile and the casing are separate components independently loaded into the firearm. 
     The projectile is loaded into the barrel muzzle end, and the casing is loaded into the barrel breech end. 
     The ammunition may include a sabot slidably attached to the projectile, such that the cap and the sabot provide seals to trap propellant gases behind the projectile. 
     The sabot includes a bottom end having at least one indentation or extension, and the cap having a top end adjacent the sabot bottom end when the projectile and the casing are inserted in the barrel, respectively, the cap top end including at least one complementary extension or indentation for insertably receiving the sabot bottom end. The at least one indentation or extension on the sabot bottom end, and the at least one complementary extension or indentation on the cap top end, comprise designed imprints formed in the sabot and the cap respectively. 
     The propellant charge may include a predetermined amount of black powder, smokeless powder, Pyrodex™, Triple Se7En™, American Pioneer™, and other synthetic replacements. 
     In a second aspect, the present invention is directed to a muzzleloading firearm ammunition system including: a barrel of the muzzleloading firearm having a breech end and a muzzle end, the barrel breech end modified to receive ammunition; ammunition comprising a projectile portion and a charge portion, the projectile portion including: a projectile; and a sabot attached to the projectile; the charge portion including: a casing having a top end, a bottom end, and a hollow body, the hollow body containing a predetermined amount of propellant charge; a cap mounted to the casing top end, the cap sealing the propellant charge from environmental elements; the casing bottom end having a rim in mechanical communication with the barrel breech end when the casing is inserted within the barrel breech end, and a primer situated at the casing bottom end and responsive to a firing pin. 
     The barrel breech end may include a chamber bushing having a breech end and a muzzle end and wherein: the chamber bushing breech end includes an accessible inner diameter for receiving the casing of predetermined outer diameter, and the chamber bushing muzzle end having an inner diameter smaller than the projectile diameter or the sabot diameter, such that it is not possible to load the projectile from the barrel breech end, or insert the projectile into the chamber bushing from the chamber bushing muzzle end. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of the invention believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which: 
         FIG. 1A  depicts one embodiment of the ammunition of the present invention; 
         FIG. 1B  is an exploded, partial cross-sectional view of the ammunition of  FIG. 1A ; 
         FIG. 2  depicts an exploded view of the ammunition of  FIG. 1A ; 
         FIG. 3  depicts a chamber bushing for insertion within the barrel of a firearm for receiving the casing of the ammunition  FIG. 1A ; 
         FIG. 4  depicts a “rotational transmission system” formed by the combination of a sabot on the projectile of the ammunition of  FIG. 1A , and cap on the casing of the ammunition of  FIG. 1A ; 
         FIG. 5  depicts the mating of the projectile and sabot combination to the casing and cap combination to form the rotational transmission system of  FIG. 4 ; 
         FIG. 6A  depicts the ammunition of the present invention in a bolt action rifle; 
         FIG. 6B  depicts the ammunition of the present invention in a break open rifle; 
         FIG. 7  depicts a perspective cross-sectional view of the top portion of the cap formed for sealing the casing; 
         FIG. 8  depicts a perspective view of the bottom portion of the sabot that interlocks with the cap of  FIG. 7 ; 
         FIG. 9  depicts a cross-sectional view of the mating of the sabot with the cap in the chamber bushing of  FIG. 3 ; and 
         FIG. 10  depicts a cross-sectional view of the mating of the sabot with the cap in the chamber bushing of  FIG. 9 , also depicting a radial cutout for receiving a rim of the casing at the breech end of the chamber bushing. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     In describing the preferred embodiment of the present invention, reference will be made herein to  FIGS. 1-10  of the drawings in which like numerals refer to like features of the invention. 
     Ammunition for firearms is introduced that allows a user to safely load a predetermined encased propellant charge in the firearm, and in the example of a muzzleloading firearm, compress a projectile to the encased propellant charge to form a round of ammunition within the firearm chamber. Although ammunition of the present invention is capable of use in a number of different types of firearms, in a preferred embodiment the ammunition is suited for muzzleloading firearms, and examples of use and applicability are best described in reference to muzzleloading firearms without limitation to other types of firearms. 
     As depicted in  FIG. 1A , ammunition  10  includes a projectile  12 , such as a cone-tipped cylindrical “bullet”, that is separate and distinct from a casing  16 . Projectile  12  is preferably encased in a sabot  14  to ensure a sealed placement of the projectile within the barrel when the projectile is inserted within the firearm, and in the case of muzzleloading firearms, inserted from the muzzle end of the firearm by a ramrod. Casing  16  is inserted from the breech end of the firearm into the barrel up to rim  18 . The sabot ensures the correct positioning of the projectile (bullet or shell) in the barrel of the firearm. The sabot is generally attached either to the projectile or inside the barrel and falls away as it leaves the muzzle. The sabot ensures that a strong seal traps propellant gases behind the projectile, and keeps the projectile centered in the barrel, thus filling the undesirable but necessary gap between the projectile and barrel, which is the space referred to as the windage. Firing a small size projectile wrapped in a sabot raises the muzzle velocity of the projectile. 
     Casing  16  is filled with propellant charge or power load. Casing  16  includes a cylindrical body and a rim  18  that may be formed integrally with the cylindrical body. Rim  18  secures a primer  20  which is designed to receive the force of the firing pin when the firearm trigger is activated. After charged propellant  22  is loaded within the cylindrical body of casing  16 , cap  24  is attached to the end of casing  16  opposite rim  18 , which seals the charged propellant from the external environment. Cap  24  is preferably designed of the same characteristics as sabot  14 ; essentially of the same material, although the two components may be designed of compatible materials which are not necessarily the same. As will be discussed in further detail herein, the top of cap  24  is designed to communicate mechanically, such as by interlocking, with the bottom of sabot  14 . This mechanical communication will ensure that projectile  12  is fully engaged by sabot  14 , such that projectile  12  will rotate with sabot  14  when the tandem combination is subjected to rifling in the barrel as it projects outwards upon its flight. 
       FIG. 1B  is an exploded, partial cross-sectional view of the ammunition  10  of  FIG. 1A . As shown, propellant charge  22  is loaded within casing  16  and sealed therein by cap  24  at one end, and rim  18  at the other end. In one embodiment, cap  24  preferably includes a cylindrical cup portion  26  for insertion within the top end of casing  16 . Cup portion  26  seals propellant charge  22  within casing  16 , providing protection for the propellant charge from outside environmental elements. 
       FIG. 2  depicts an exploded view of ammunition  10 . In this figure, the primer components  20   a,b,c  that are insertable within rim  18  of casing  16  are also shown. 
       FIG. 3  depicts a chamber bushing  30  for insertion within the barrel of the firearm. Chamber bushing  30  is a reducing bushing that reduces the inner diameter of the breech end of the barrel that receives casing  16 . 
       FIG. 4  depicts a “rotational transmission system” formed by the combination of sabot  14  and cap  24 . Cap  24  has at least one indentation  28  on its top face or peripheral edge which is received by a mating complementary extension  29  on the exposed bottom of sabot  14 . Alternatively, the indentation on cap  24  may instead be an extension extending from the face or edge and a mating complementary indentation may be formed on sabot  14 . As depicted in  FIG. 4 , indentation  28  may be a star pattern having radially extended spokes, and extension  29  on sabot  14  may be a similar complementary pattern for interlocking with indentation  28  during firing. The rotational movement between sabot  14  and cap  24  is achieved inside the barrel when the firearm is fired and the ammunition is exiting the barrel, thereby allowing the rifling on the barrel&#39;s interior surface to rotate the cap/sabot combination. Arrow  32  depicts the direction of compression of projectile  12  by a ramrod from the muzzle end of the barrel. 
       FIG. 5  depicts the mating of projectile  12  with sabot  14  to casing  16  with cap  24 . The indentation  28  on the top surface of cap  24  receives extension  29  on the bottom surface of sabot  14 , and these features mate and interlock to ensure concurrent rotation when acted upon by the barrel&#39;s rifling. Arrow  34  depicts a rotational direction of spin when the cap/sabot combination is acted upon by the barrel rifling. Other interlocking mechanisms may be used to mechanically communicate the sabot to the cap with performance restrictions, and the present invention is not limited to any one particular interlocking mechanism. 
       FIG. 6A  depicts the ammunition of the present invention used in a bolt action rifle  40 . Chamber bushing  30  is inserted into the breech end of the barrel. As will be discussed in further detail herein, chamber bushing  30  is a new component of an ammunition system introduced for loading and safety considerations. Projectile  12  is compressed into the barrel from the muzzle end (not shown) and the tight sabot  14  around projectile  12  is in slidable contact with rifling  44  of barrel  42 . Primer  20  is aligned to be engaged by firing pin  46  upon firing. In a similar manner,  FIG. 6B  depicts the ammunition of the present invention as used in a break open rifle  50 . 
       FIG. 7  depicts a perspective cross-sectional view of the top portion of cap  24 . Preferably, cap  24  includes a plurality of indentations  28 , or extensions, or any combination thereof, for mating with a complementary mating bottom portion of sabot  14 . Cap  24  includes an extended cylindrical bottom  33  forming a preferred angled cup  35  for capturing gases upon detonation of the propellant charge. 
       FIG. 8  depicts a perspective view of the bottom portion of sabot  14 . In this example, sabot  14  includes a plurality of extensions  29  for complementary mating with indentations  28  of cap  24 . A “star” configuration is depicted; however, the present invention is not limited to any particular design, and it is possible for each mating surface of the sabot and cap to have a combination of indentations and extensions that mate in a complementary fashion. As noted in  FIG. 8 , sabot  14  may further include slots  37  for releasably sliding on the projectile. 
       FIG. 9  depicts a cross-sectional view of the mating of sabot  14  with cap  24  in chamber bushing  30 . In at least one embodiment, chamber bushing  30  is inserted in the breech end of barrel  44  for the purpose of receiving and securing the casing-cap combination. Chamber bushing  30  is designed to perform the chamber function of the barrel. Tapered projection  42  on chamber bushing  30  ensures that a difference in radius exists between the outside diameter of cap  24  and the innermost diameter of chamber bushing  30  at the tapered projection  42 . In this manner, it is impossible to introduce projectile  12  and sabot  14  into the muzzle end of chamber bushing  30 . 
     Additionally, as shown in  FIG. 10 , chamber bushing  30  includes a radial cutout  45  for receiving rim  18  of casing  16  at the breech end. By design, the radius of radial cutout  45  is such that it is not possible to introduce the projectile through the same chamber bushing breech end that is measured for the casing. 
     By virtue of this novel design, it is possible to introduce an ammunition system with a lighter, less expensive ammunition for firearms, including for the preferred use of muzzleloading firearms. The ammunition&#39;s casing may be fabricated of recyclable plastic, and may be color coded for distinguishing different types of loads. Advantageously, predetermined amounts of charged propellant may be fabricated and purchased separately. Additionally, different charged propellants, utilizing different powders, can be safely loaded (since they are already measured and secured in the casing) without risk of over-loading or causing subsequent detrimental damage. 
     For example, smokeless powder, which lends itself to a more critical usage requirement, can be used in a muzzleloading firearm more safely, and with less risk of overloading. Charges, such as nitrocellulose based smokeless powder, are legal propellants in muzzleloaders designed for its use. Other “smokeless powder” charges include Pyrodex™, Triple Se7En™, American Pioneer™, and other synthetic replacements. Pursuant to the present invention, it is possible to load a predetermined amount of smokeless powder into the casing and seal this powder with a cap, such that a user can safely select “smokeless powder” ammunition for use without risk of overcharging the firearm. 
     While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention. 
     Thus, having described the invention, what is claimed is: