This invention relates generally to a sabot and breech plug system particularly for muzzleloading firearms, but may also be applied to non-muzzleloading firearms, and more particularly to a sabot having an extended casing for containing propellant and a slotted top portion for securing a bullet. The propellant is ignited by gases that enter the lower portion of the sabot from a puncture developed by the insertion of a breech plug having a sharpened forward edge for breaking the breech end of the sabot, which is designed to be vulnerable to puncture.
It is well known in the field of ballistics that when a projectile passes through a gun bore at high speed, the friction between the projectile jacket and the barrel generates a considerable amount of heat. This friction causes barrel erosion or barrel wear which results in ineffective gas sealing, which further results in considerable loss of projectile velocity, eventually leading to unreliable and inconsistent flight of the projectile.
Sabots were introduced as a way to mitigate these issues. The trend in muzzleloading has been the introduction of an undersized bullet within a polymer sabot in a barrel sized for a larger caliber bullet. The undersized bullet body has a higher muzzle velocity than the larger caliber bullet providing improved ballistic characteristics.
The sabot is sized to approximate the inner diameter of the barrel such that the sabot tightly seals against the barrel to efficiently propel the bullet and engage the rifling of the barrel to impart spin to the bullet. A sabot is used on a projectile fired from a firearm, such as a bullet or shell, to ensure the correct positioning of the bullet or shell in the barrel of a gun. The sabot is generally attached either to the projectile or inside the barrel, and is designed to fall away as the projectile leaves the firearm muzzle. Essentially, there is a limit to what an unjacketed bullet can endure without stripping from the rifling of the barrel, and for that matter, what a jacketed bullet can take as well.
A sabot is a sleeve that holds the bullet during discharge while simultaneously ensuring a gas seal. It keeps a sub-caliber flight projectile, such as a relatively small bullet or arrow-type projectile, in the center of the barrel when fired while simultaneously trapping propellant gas behind the projectile. The sabot is necessary because efficient aerodynamic design of a flight projectile does not always accommodate efficient interior ballistic design to achieve high muzzle velocity.
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. Generally, a sabot is an encasing thermo-plastic cup that generally falls away from the projectile after it exits the gun. The sabot further eliminates the need for a lubricating means and assures that there is a good seal between the projectile and the bore of the barrel.
Sabots may also be molded directly on to a projectile. Saboted bullets are used to form a strong seal that traps propellants behind the projectile, and keep the projectile centered in the barrel. When a saboted projectile is fired, the sabot blocks the gas, and carries the projectile down the barrel. The sabot is also also is acted upon by the grooves of the rifling. Sabots come in many forms, including a cup sabot, which supports the base and rear end of a projectile, and an expanding cup sabot, which upon firing uses the inertia from the rotation of the projectile to open up side sabot segments surrounding the projectile and release it. Other sabots are also available in the art, such as base sabots, spindle sabots, and ring sabots. A base sabot has a one piece base which supports the bottom of the projectile, and separate pieces that surround the sides of the projectile and center it. A spindle sabot uses at least two matched longitudinal rings which have a center section in contact with a long arrow-type projectile; a front section which centers that projectile in the barrel and provides an air scoop to assist in sabot separation upon muzzle exit, and a rear section which both centers the projectile and seals propellant gases with a ring around the outside diameter. A ring sabot uses the rear fins on a long rod projectile to help center the projectile and ride the bore, and the multi-petal sabot forms only a single bulkhead ring around the projectile near the front, and seals gases from escaping past it.
It is well known in the art that 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 measurement of the powder (propellant) is not an exact science, and tends to introduce inaccuracies and inconsistencies in firing. A predetermined load provides for the user a way to eliminate some of the inaccuracies and inconsistencies, especially during field loading.
Saboted bullets are popular with muzzleloading firearms because they simplify the loading process. They generally yield higher velocities and flatter trajectories. However, it is always an art for the muzzleloader aficionado to find just the right combination of specific powder, charge, sabot, bullet, and primer to use.
Without limiting the scope of the invention, a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Description of the Preferred Embodiments below.
Bearing in mind the problems and deficiencies of the prior art, it is an object of the present invention to provide a preloaded sabot bullet for use in a muzzleloader.
It is another object of the present invention to provide a sabot having the ability to contain propellant while simultaneously securing a bullet at the sabot's forward end, and being responsive to a breech plug adapted for use with the sabot of the present invention at the sabot's breech end.
It is yet another object of the present invention to provide a breech plug for working in combination with a preloaded sabot.
The present invention is directed to, in a first aspect, a preloaded sabot ammunition comprising: a sabot having a closed breech end, an open muzzle end, and a substantially cylindrical body extending from the closed breech end to the open muzzle end, the cylindrical body having an outside diameter complementary to an inside diameter of a bore of a firearm barrel, and an internal cavity; a propellant charge inserted within the internal cavity of the cylindrical body from the open muzzle end of the sabot, the propellant charge having a top end exposed to the open muzzle end of the sabot upon insertion; a projectile slideably inserted with the sabot open muzzle end proximate the top end of the propellant charge, and held by the sabot.
The closed breech end of the sabot has a thickness less than sidewalls of the cylindrical body, such that the closed breech end of the sabot is vulnerable to puncture by a breech plug fixed in a breech end of the barrel.
The cylindrical body forms a plurality of pedals, defined by a plurality of slots, extending axially from the open muzzle end of the sabot and terminating at a position intermediate the closed breech end of the sabot, the intermediate position allowing the plurality of pedals to extend to, but not below, the top end of the propellant charge when the propellant charge is fully inserted within the sabot. The cylindrical body may include a structural demarcation into the internal cavity separating the plurality of pedals from a portion of the internal cavity housing the propellant charge. The structural demarcation may comprise a circumferential lip extending radially inwards into the internal cavity.
A cap securable to the structural demarcation may be employed, the cap securing the propellant charge within the internal cavity. The cap may include a circumferential groove for mating with the circumferential lip extending radially inwards into the internal cavity.
The propellant charge comprises free or pre-packaged granular black powder, such that in any pre-packaged form, a package containing the granular powder is vulnerable to puncture by a breech plug fixed in the breech end of the barrel.
In a second aspect, the present invention is direct to a muzzleloading ammunition comprising: a sabot having an open end and a closed end, and an extended hollow body therebetween, the extended body being substantially cylindrical with a radially facing interior surface, the sabot closed end being vulnerable to puncture by a breech plug fixed in a breech end of a firearm barrel; an extended body lip or extended body groove circumferentially situated within the extended hollow body on the radially facing interior surface, placed intermediate the open end and the closed end of the sabot; a propellant charge inserted within the extended hollow body from the open end of the sabot and below the extended body lip or extended body groove; a cap inserted into the open end of the sabot, having a complementary cap groove or cap lip for interlocking with the extended body lip or extended body groove, respectively, and sealing the propellant charge a distance from the open end of the sabot; and a projectile inserted into the open end of the sabot and situated proximate the cap, such that the projectile extends approximately to or above the open end of the sabot.
The ammunition includes a plurality of resilient pedals defined by slots, extending axially from the open end of the sabot to a position above the extended body lip or extended body groove, the plurality of resilient pedals securing the projectile to the sabot.
The extended hollow body includes a radially facing exterior surface having a diameter complementary to the inside diameter of a bore of a muzzleloader firearm used to fire the muzzleloading ammunition.
In a third aspect, the present invention is directed to a breech plug for a muzzleloader firearm, the breech plug adapted for use with ammunition having a preloaded sabot, the breech plug comprising: a cylindrical body extending from a first end to a second end along an axial or longitudinal axis, the cylindrical body including a threaded, or tightly coupled connection for removable installation with a corresponding complementary connection at a breech end of a barrel of the muzzleloader; a nose portion at a muzzle end of the breech plug; a cavity or pocket at a breech end of the breech plug for receiving a primer cap; an internal passage for transporting gas from the primer cap into the barrel through the nose portion of the breech plug, upon firing of the muzzleloader firearm; the nose portion having a piercing component for puncturing the preloaded sabot upon final placement of the preloaded sabot into the barrel, such that when the muzzleloader firearm is fired, hot gas from the primer cap is transported through the breech plug, into the punctured preloaded sabot, where a propellant charge is ignited.
The piercing component may comprise a sharp edged wedge shaped structure for puncturing the preloaded sabot, the wedge shaped structure having a portion of the internal passage passing therethrough.
The piercing component may comprise a pin-shaped structure for puncturing the preloaded sabot, the pin-shaped structure having a portion of the internal passage passing therethrough.
The piercing component may include a cup-shaped structure extending in a direction of the barrel muzzle end, the cup-shaped structure having narrow or sharp edges at a periphery for piercing the preloaded sabot, the cap-shaped structure having a portion of the internal passage passing therethrough.
In a fourth aspect, the present invention is directed to a preloaded sabot ammunition system comprising: a sabot including: a closed breech end, an open muzzle end, and a substantially cylindrical body extending from the closed breech end to the open muzzle end, and an internal cavity within the cylindrical body, the cylindrical body having an outside diameter complementary to an inside diameter of a bore of a breech end of a firearm barrel; a propellant charge insertable within the internal cavity of the cylindrical body from the open muzzle end of the sabot, the propellant charge having a top end exposed to the open muzzle end of the sabot upon insertion; a projectile slideably inserted within the sabot open muzzle end proximate the top end of the propellant charge, and held by the sabot; and a breech plug including: a cylindrical body extending from a first end to a second end along a longitudinal axis, the cylindrical body including a threaded, or tightly coupled, connection for removable installation with a corresponding complementary connection at a breech end of a barrel of the firearm; a nose portion at a muzzle end of the breech plug; a cavity or pocket at a breech end of the breech plug for receiving a primer cap; an internal borehole for transporting gas from the primer cap into the barrel through the nose portion of the breech plug, upon firing of the firearm; the nose portion having a protrusion for puncturing or piercing the sabot upon placement of the sabot into the breech end of the barrel, such that when the firearm is fired, hot gas from the primer cap is transported through the breech plug, into the punctured or pierced sabot, igniting the propellant charge.
In a fifth aspect, the present invention is directed to a method of loading a muzzleloader firearm comprising: attaching a breech plug to a breech end of a barrel of the muzzleloader firearm, the breech plug having a piercing component at an end facing the breech end of the barrel; loading a preloaded sabot ammunition into the muzzle end of the barrel of the muzzleloader firearm, and seating the preloaded sabot ammunition at the breech end of the barrel; piercing the preloaded sabot ammunition with the piercing component of the breech plug.
The piercing of the preloaded sabot ammunition preferably occurs during the seating of the ammunition.
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:
In describing the preferred embodiment of the present invention, reference will be made herein to
The current state of the art of saboted bullets is depicted in
The bullet or projectile 12, shown in
Propellant charge, generally in the form of tamped black powder, is placed in the barrel of a muzzleloader firearm at the breech end prior to the placement of the saboted bullet. The sabot-shrouded bullet is then placed in the muzzle end of the firearm barrel and pushed into place by a ramrod. Upon firing of the muzzleloader firearm, the propellant is acted upon by ignited gas delivered through a breech plug, which it in turn causes abundant propellant gas that forces the saboted bullet out of the barrel.
The breech plug is removably attached to the barrel. The breech plug includes a central passage 48 (flash channel/fire channel) that communicates between a primer, a capillary tube 44, and the flash hole. The central passage 48 terminates at a primer pocket or cavity at the breech end of the breech plug. The primer pocket has a diameter greater than the central passage.
One preferred embodiment of the present invention is directed to a muzzle loaded ammunition round. In this embodiment, unlike the prior art, and genuinely unique to firearms, particularly muzzleloader firearms, a saboted bullet is presented where the bullet and propellant charge are both encompassed by the sabot. That is, the propellant charge is contained within an extended lower portion of the sabot cylindrical body or casing of the sabot, while the upper portion of the sabot secures the bullet. In this manner, the sabot is introduced as a “preloaded” component.
In a preferred embodiment, the sabot has a closed breech end, an open muzzle end, and a substantially cylindrical body extending from the closed breech end to the open muzzle end. That is, the sabot is closed at one end and open at the other, such that upon insertion into the barrel of the firearm, the closed end is proximate the breech end of the firearm, and the open end is proximate the muzzle end of the firearm. The sabot's cylindrical body has an outside diameter complementary to an inside diameter of the bore of the firearm barrel, and an internal cavity;
A propellant charge is inserted within the internal cavity of the cylindrical body from the open muzzle end of the sabot; the propellant charge includes a top end exposed to the open muzzle end of the sabot upon insertion.
A projectile may then be slideably inserted with the sabot open muzzle end proximate the top end of the propellant charge, and held by the sabot. In this manner, the preferred embodiment of the preloaded sabot has the configuration as delineated in
The propellant charge 24 is contained within sabot 22 below the breech end of slots 28, which are formed by the leaves or pedals 32, 34 of the muzzle end of the sabot, so that propellant charge 24 and subsequent gases formed by ignition cannot escape through the slots 28. Projectile or bullet 30 is press fitted on top of cap 26 so that the slotted top portion of sabot 22 forms a projectile receiving chamber 29, which in turn releases projectile 30 upon exiting the barrel.
The sabot can be constructed at least in part out of a resilient thermoplastic material. In the embodiment depicted by
When propellant charge 24 is ignited it burns very rapidly, combustion gases being formed in the cartridge chamber which produce an enormously high pressure. Owing to the locking of the firearm at the breech of the barrel, and the sealing at that end by the breech plug, these combustion gases cannot stream backwards but they exert instead a pressure on the sabot 22 and the projectile 30, which initiates a forward thrust on the projectile 30, launching the saboted projectile through the bore of the barrel under increasing acceleration.
The breech end 21 of sabot 22 is preferably made of the same material as the outer casing portion 23, and preferably thinner in construction. Although, depending upon the sabot material, it may be possible for the breech end to be of the same thickness as the sabot casing provided, as discussed below, the breech end of the sabot is capable of being punctured by a complementary breech plug. This thinner, or “puncture vulnerable” area of the sabot is acted upon by a uniquely shaped breech plug 40 having a forward end 42 capable of puncturing the breech end 21 of sabot 22. Preferably, breech plug 40 includes a sharp edged wedge shaped extension or pin-shaped extension or other “piercing” design, capable of puncturing the thin-walled or puncture vulnerable area of breech end 21 of sabot 22.
Breech plug 40 is specifically designed for the preloaded sabot system of the present invention, insomuch as breech plug 40 has at least one feature at its muzzle-facing end for puncturing the breech end of the sabot. Breech plug 40 is removable from the breech end of the barrel. In a preferred embodiment, breech plug 40 includes a central passage or flash channel 48 extending therethrough, and ending in a center axial capillary tube 44 for gas egress out the breech plug's muzzle end from a flash hole, as depicted in
Upon insertion of the ammunition, which comprises a combination of sabot 22, propellant charge 24 inserted within the sabot, an (optional) cap 26 to seal the propellant charge 24, and projectile 30 encased by the sabot pedals 32, 34, into the muzzle end of the barrel towards breech plug 40, the puncture vulnerable breech end 21 of sabot 22 is pierced by a piercing component 62, which is shown in the figures, for exemplary purposes only, as a sharp edged wedge shaped protrusion extending from the forward or muzzle end 42 of breech plug 40. Gasses developed by the activation or firing of a primer cap at the breech end of breech plug 40 traverse through central passage 48 to capillary tube 44 and its associated flash hole, through the pierced interface at the breech end 21 of sabot 22, which ultimately ignites propellant charge 24 to act upon the sabot encased projectile 30.
Typically, by the time projectile 30 has reached the muzzle end of the barrel, propellant charge 24 has been completely burnt up, and the projectile reaches its highest level of acceleration. The sabot assists in sealing the gases behind the projectile in order to maximize the acceleration of the projectile leaving the barrel.
In
In addition, propellant charge 24 may be separately packaged such that a cap is not required to hold or seal the propellant in place. In this manner, in a prepackaged design, the extension of lip 25 into the cylindrical cavity of sabot 22 may be sufficient to hold the packaged propellant from falling out of sabot 22 prior to the insertion of projectile 30.
As depicted in
As depicted in the figures, capillary tube 44 is shown exiting the nose end of the breech plug 42 to deliver the gasses of the primer, which is activated via a primer cap within cavity 50 at the breech end of the breech plug during firing.
In a preferred embodiment, a preloaded sabot system is configured; however, it should be understood that the preloaded sabot, inclusive of a projectile at one end, need not be used solely for a muzzleloading firearm, insomuch as the thin-walled portion of the sabot breech end may be punctured by means other than a breech plug, which allows the preloaded sabot to be used with non-muzzleloading firearms. Furthermore, a preloaded sabot, without an inserted projectile, may be easily constructed and made commercially available for different types of projectiles, which can be inserted by the user prior to loading.
In another aspect of the present invention, a method of firing a firearm is taught, in a first embodiment being a muzzleloading firearm, wherein the method includes providing a preloaded sabot. The sabot having an extended casing area to receive propellant charge, and a further top portion slotted extension for receiving a projectile, is presented in a firearm barrel. The sabot may secure the propellant charge by receiving an insertable cap. A breech plug is inserted into the breech end of the barrel. The breech plug is configured to effectuate a puncture to the breech end of the sabot upon insertion of the sabot. The puncture being in the lower portion of the sabot, such that gasses released from a primer cap located at the opposite end of the breech plug flow through a capillary tube axially placed in the breech plug, and exit into the lower portion of the preloaded sabot, which ignites the propellant charge, and accelerates the sabot system out of the barrel.
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.
Number | Date | Country | |
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62404881 | Oct 2016 | US |
Number | Date | Country | |
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Parent | 15723595 | Oct 2017 | US |
Child | 16822796 | US |