Patent Publication Number: US-9417024-B2

Title: Asymmetric muzzle compensator for firearm

Description:
FIELD OF INVENTION 
     This invention relates to devices installed on or integrated into the muzzle of a firearm. More specifically, the invention relates to a compensator intended to counteract the tendency of a firearm&#39;s barrel to rise after firing. 
     BACKGROUND OF THE INVENTION 
     The front end of a firearm (or the muzzle end of the barrel) tends to rise after firing. This occurs primarily because, for most firearms, the center line of the barrel is positioned above a center of contact established between the shooter and the firearm&#39;s grips or stock. The reactive force, or the recoil force, created when a bullet is fired and propellant gases, or propulsion gases, exit the muzzle, acts directly along the center line of the barrel and toward the rear of the firearm, where the shooter is generally positioned. When this line of force is above the center of contact between the shooter and the firearm, the force creates a “moment,” or a rotational force, about the center of contact between the shooter and the firearm, which causes the firearm to rotate about the center of contact such that the muzzle end of the firearm rises upward. Such muzzle rise, or muzzle climb, is particularly evident for firearms having gripping features (e.g., a stock or grip) arranged such that a vertical distance (i.e., the moment arm) between the center line of the barrel and a center of contact with the shooter is particularly large. 
     A muzzle brake is a device connected to or on the muzzle of the barrel that redirects propellant gases to counter recoil forces. This may be accomplished in two general ways. First, a muzzle brake may present a surface against which the propellant gases impact, causing that transferred force to pull the barrel forward, counteracting part of the recoil forces. Second, redirection of propellant gases laterally, or even somewhat rearwardly, reduce or neutralize the effect of the muzzle blast. 
     In other cases, a muzzle attachment or porting that is provided along the top of the barrel or that is otherwise upwardly directed, used in combination with minimal or absent redirection or porting that is downwardly directed, exerts a downward force on the muzzle end of the barrel that at least partially counteracts the muzzle rise or muzzle climb described above. Such muzzle devices, whether a muzzle brake, flash suppressor, or compensator, include outlet ports that are asymmetric from top to bottom, about an imaginary horizontal plane. That is, porting is minimized or absent along the bottom of the device and is maximized toward the top and/or sides of the device. The porting in such devices, however, is symmetrical left to right, about an imaginary vertical plane. 
     Although not previously recognized, and generally not perceived by shooters, the muzzle rise or muzzle climb is not solely in an upward direction. For a right handed shooter, the muzzle rise or muzzle climb includes a vector somewhat to the right (from the shooter&#39;s perspective) of directly “up.” Accordingly, after firing a shot, the shooter must move the muzzle downwardly and slightly to the left to realign with the target. Even with very effective compensators having left-to-right symmetrical porting that nearly eliminates muzzle rise or muzzle climb, some movement toward the left (again, for right handed shooters) is required to realign the barrel and sites on the target. Causes may include the ergonomics of how a firearm is typically held by a shooter, the effect of rifling (which usually spins the projectile in a right handed direction), and the cycling of an auto-loading action (including rotation and reciprocation of the bolt and ejection of a spent ammunition casing). 
     SUMMARY OF THE INVENTION 
     The present invention according to one embodiment provides a muzzle device for use with a muzzle end of a firearm barrel. The muzzle device includes a body having a forward end, a rearward end, and a central passageway extending therebetween along a central axis of the body. The body is mountable to the muzzle end of the firearm barrel such that the central axis is aligned with a barrel axis defined by a bore of the firearm barrel. The muzzle device further includes a plurality of ports provided on the body and spaced circumferentially about the central axis, the ports extending generally radially outward from the central axis and open to the central passageway to provide fluid communication between the central passageway and an ambient environment external of the body. The ports are configured to direct propulsion gases generally radially outward therethrough when the firearm is discharged. The body includes a right-side portion and a left-side portion defined by a vertically-oriented imaginary plane passing through the central axis of the body. The ports are provided on the body such that the right-side portion directs a greater volume of propulsion gases therethrough than the left-side portion when the firearm is discharged. 
     According to another feature of the invention, a circumferential spacing of the ports provided on the right-side portion may be smaller than a circumferential spacing of the ports provided on the left-side portion. 
     According to another feature of the invention, at least one of the ports provided on the right-side portion may be formed with a diameter that is larger than a diameter of each of the ports provided completely on the left-side portion. 
     According to another feature of the invention, the right-side portion may include an upper-right quadrant and a lower-right quadrant of the body, and the left-side portion may include an upper-left quadrant and a lower-left quadrant of the body, the upper and lower quadrants being defined by a horizontally-oriented imaginary plane passing through the central axis of the body, and the ports being provided on the body such that the upper-right quadrant directs a greater volume of propulsion gases therethrough than the upper-left quadrant when the firearm is discharged. 
     According to another feature of the invention, the body may include an inner chamber extending along the central axis and having a diameter that is larger than a diameter of the bore of the firearm barrel. 
     According to another feature of the invention, the muzzle device may include a blast cone positioned within an inner chamber of the body and having a rearwardly-directed surface configured to receive at least a portion of a forwardly-directed force exerted by the propulsion gases when the firearm is discharged. 
     According to another feature of the invention, the muzzle device may include at least one intake port provided on the body separate from the plurality of ports and extending into an inner chamber of the body, the at least one intake port configured to draw air from the ambient environment into the inner chamber when the firearm is discharged. 
     The present invention according to another embodiment provides a firearm barrel for use with a firearm. The firearm barrel includes a barrel body having a muzzle end from which a projectile exits when the firearm is discharged, a bore defining a barrel axis, and a plurality of ports provided at the muzzle end of the barrel body and spaced circumferentially about the barrel axis. The ports extend generally radially inward toward the barrel axis and open to the bore to provide fluid communication between the bore and an ambient environment external of the barrel body. the ports configured to direct propulsion gases generally radially outward therethrough when the firearm is discharged. The barrel body includes a right-side portion and a left-side portion defined by a vertically-oriented imaginary plane passing through the barrel axis, the ports being provided on the barrel body such that the right-side portion directs a greater volume of propulsion gases therethrough than the left-side portion when the firearm is discharged. 
     Various other features, benefits, and aspects of the present invention will become apparent to a person of ordinary skill in the art upon considering the drawing figures and detailed description below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Like reference numerals are used to indicate like parts throughout the various figures of the drawing, wherein: 
         FIG. 1  is an isometric view of a compensator according to one embodiment of the present invention shown attached to the muzzle portion of a firearm barrel; 
         FIG. 2  is a top plan view thereof; 
         FIG. 3  is a bottom plan view thereof; 
         FIG. 4  is a longitudinal section view taken substantially along line  4 - 4  of  FIG. 1 ; 
         FIG. 5  is a cross sectional view taken substantially along line  5 - 5  of  FIG. 2 ; 
         FIG. 6  is a cross sectional view taken substantially along line  6 - 6  of  FIG. 2 ; and 
         FIG. 7  is a fragmentary sectional view of the compensator taken substantially along line  7 - 7  of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the various figures of the drawing, and first to  FIGS. 1-3 , therein is shown at  10  a compensator according to one embodiment of the present invention. The illustrated device  10  is in the form of an attachment that may be removably coupled to the muzzle end of a firearm barrel  12 , by threadedly engaging mounting threads  44  provided on a radially inner surface of the device  10  with threads  46  provided on a radially outer surface of the muzzle end of the barrel  12 . The body of the device  10  may include one or more wrench flats  14  to facilitate attachment of the device  10  to the barrel  12 . The body includes a central passageway having a central axis  16  that is aligned with the axis of the bore  18  of the barrel  12 . At a forward end  20  of the device  10 , the central passageway opens to an outlet opening  22 , which is sized to allow free passage of a projectile therethrough. In practice, the outlet opening  22  must be slightly greater in diameter than the bore  18  of the barrel  12 , the exact size of the outlet opening  22  being dependent on the caliber of the firearm. 
     As shown in  FIG. 4 , the body of the compensator  10  may include an inner chamber  24  having a cross-sectional area larger than that of the bore  18 . For example, a diameter of the inner chamber  24  may be larger than the diameter of the bore  18  and may also be larger than the diameter of the outlet opening  22 . According to one embodiment of the invention, the compensator  10  may include an internal blast cone  26  positioned in the inner chamber  24  near the forward end  20 . This blast cone  26  may be made of a material selected to be particularly erosion resistant, such as AISI T15 High Speed Tool Steel. The blast cone  26  includes an axial passageway  28  coaxially aligned with the axis  16  of the compensator  10  and with the bore  18 . The axial passageway  28  of the blast cone  26  may include a forward portion  30  that is enlarged in cross section and which may substantially match a cross-sectional area or diameter of the outlet opening  22 . The inner chamber  24  of the compensator  10  may be formed to have an annular wall  32  projecting radially inward at the forward end  20  and against which the blast cone  26  may be seated and secured. Accordingly, the blast cone  26 , which is subjected to a considerable amount of forwardly-directed force exerted by propellant gases escaping the muzzle of the barrel  12  when a projectile is fired, cannot be dislodged forwardly from its proper position within the inner chamber  24 . The blast cone  26  may be sized to press fit into position against the annular wall  32  and/or may be attached in place, such as by welding or brazing. A rearwardly-directed frusto-conical shape of the blast cone  26  provides a surface of increased area against which high velocity propellant gases impinge when the firearm is discharged. Consequently, a portion of the forwardly-directly force exerted by the propellant gases is transferred to the compensator  10  and to the barrel  12 , thereby counteracting at least a portion of the rearwardly-directed recoil forces exerted by the firearm. Additionally, the frusto-conical shape of the blast cone  26  facilitates redirection of the propellant gases through radial openings, described below. 
     The body of the compensator  10  includes a ported section having a plurality of outlets or ports  34  for venting and directing high velocity propulsion gases from the inner chamber  24  radially outwardly in directions substantially transverse to the central axis  16 . As shown in the illustrated embodiment, these ports  34  may extend radially through the body of the compensator  10 , connecting the inner chamber  24  with the atmosphere surrounding the device  10  in fluid communication. If desired, the ports  34  may include a flared portion  36  at a radially outer location where the port  34  meets the exterior surface of the compensator  10 . These flared portions  36  may be formed conically, such as with a counter sink mill tool, or may be cupped, such as with a ball end mill. The flared portion  36  helps to more rapidly disperse the high velocity gases exiting through the ports  34 . 
     As is particularly evident in  FIGS. 2 and 3 , showing top and bottom views of the compensator  10 , respectively, the ports  34  may be spaced along the axial length of the compensator  10 , such as in circumferentially staggered rows, where the ports  34  of one row are offset in a circumferential direction from corresponding ports  34  of an adjacent row. The distribution of the ports  34  and, accordingly, the collective cross-sectional area and volume defined by the ports  34  and thus the volume of propellant gases expelled therethrough, is asymmetrical in a left-to-right, side-to-side relationship. In other words, the ports  34  are arranged asymmetrically about a vertically-oriented imaginary plane that passes through the central axis  16  and defines left and right portions of the compensator  10 . 
     Referring now also to  FIGS. 5 and 6 , therein are shown cross-sectional views along representative axially spaced and circumferentially staggered rows of outlet ports  34 . Looking from the perspective of a shooter holding a firearm having a compensator  10  according to the present invention (i.e., from the rear of the firearm looking forward, down the barrel  12 ), the circumferential portions of the compensator  10  body may be considered in four sections or quadrants. A first, upper-right quadrant may be visually defined between a twelve o&#39;clock position (directly up) and a three o&#39;clock position (directly to the right); a second, lower-right quadrant may be visually defined between the three o&#39;clock position (directly to the right) and a six o&#39;clock position (directly down); a third, lower-left quadrant may be visually defined between the six o&#39;clock position (directly down) and a nine o&#39;clock position (directly to the left); and a fourth, upper-left quadrant may be visually defined between the nine o&#39;clock position (directly to the left) and the twelve o&#39;clock position (directly up). In this manner, the twelve o&#39;clock and six o&#39;clock positions collectively define a vertically-oriented imaginary plane passing through the central axis  16 , thereby defining a right-side portion and a left-side portion of the body of the device  10 . Similarly, the nine o&#39;clock and three o&#39;clock positions collective define a horizontally-oriented imaginary plane passing through the central axis  16 , thereby defining a top portion and a bottom portion of the body of the device  10 . 
     Because orientation of the compensator  10 , relative to vertical and horizontal when the firearm is being held by a shooter, is important to understanding the present invention and proper installation of the device  10 , the compensator  10  body may include upper indexing marks  38  (shown in  FIG. 2 ) indicating a top portion of the device  10  to be oriented upwardly in alignment with the twelve o&#39;clock position, and lower indexing marks  40  (shown in  FIG. 3 ) indicating a bottom portion of the device  10  to be oriented downwardly in alignment with the six o&#39;clock position. As shown in  FIG. 4 , because orientation of the device  10  on the barrel  12  relative to vertical and horizontal is important, and because the mounting threads  44  on the device  10  and threads  46  on the barrel may be cut without regard to vertical or horizontal orientation, it may be necessary to “time” the final position of the device  10 , during installation thereof onto the barrel  12 , with one or more shims  48 . As shown, the shims  48  may be seated within a pocket  50  formed at the rear of the device  10  and against a radially extending annular shoulder  52  of the barrel  12 . Through use of the shims  48 , the device  10  may be rotatably positioned such that the upper indexing marks  38  are substantially aligned with the twelve o&#39;clock position (directly up), and the lower indexing marks  40  are substantially aligned with the six o&#39;clock position (directly down). Additionally, if desired, the device  10  may be permanently affixed to the barrel  12  by pinning, such as through a provided opening  54  located at the threaded portion  44 , so as to maintain the device  10  in the desired rotational orientation relative to the barrel  12 . 
     According to a feature of the illustrated embodiment, the circumferential spacing of the radial ports  34  is closer, thereby providing an increased outlet flow of propellant gases, in the upper-right quadrant than in the upper-left quadrant. This left-to-right, asymmetric relationship may also be applied, if desired, to upper portions of the lower-right quadrant and the lower-left quadrant. As shown in the illustrated embodiment, the circumferential spacing of the outlet ports  34  is varied to achieve this differentiation.  FIGS. 5 and 6  show that the circumferential spacing between ports  34  in the upper-left and lower-left quadrants (spacing shown at “a”) may be at approximately 37.5 degrees, while the circumferential spacing of ports  34  in the upper-right and lower-right quadrants (spacing shown at “b”) may be approximately 25 degrees. In either case, generally none of the ports  34  are oriented directly downward toward the six o&#39;clock position. Additionally, the ports  34  in the lower-left and lower-right quadrants may be fewer in number or smaller in combined cross-sectional area, and thus volume, than the ports  34  in the corresponding upper-left and upper-right quadrants, respectively. As shown in  FIGS. 5 and 6 , the lowermost port  34  in the lower-left quadrant may be positioned at approximately 30 degrees (shown at “d”) to 48.5 degrees (shown at “e”) from the bottommost point of the device  10  at the six o&#39;clock position, indicated by the lower indexing mark  40 . Similarly, the lowermost port  34  in the lower-right quadrant may be positioned at approximately 30 degrees (shown at “f”) to approximately 42.5 degrees (shown at “g”) from the bottommost point of the device  10 , indicated by the lower indexing mark  40 . 
     If desired, though not illustrated, the circumferential spacing of one or more rows of ports  34  may vary progressively in circumferential directions about the device  10 . More particularly, the circumferential spacing of the ports  34  may incrementally decrease, such that the ports  34  become more closely-spaced, in circumferential directions advancing toward and into the upper-right quadrant. Similarly, in such configuration, the circumferential spacing of the ports  34  incrementally increases, such that the ports  34  become further spaced apart, in circumferential directions advancing out of and away from the upper-right quadrant. Additionally, as shown in the illustrated embodiment, the axial spacing of the staggered rows of ports  34  may remain substantially constant along a length of the ported section of the device  10 . 
     In an alternative embodiment, not shown herein, rather than forming the ports  34  with uniform diameters and positioning the ports  34  with varying circumferential spacing for mitigating muzzle rise, as described above, the same effect may be achieved by forming the ports  34  with diameters that vary circumferentially about the device  10 , such that a collective volume defined by the ports  34  positioned in the upper-right quadrant is greater than a collective volume defined by the ports  34  positioned in each of the lower-right quadrant, the upper-left quadrant, and the lower-left quadrant. For example, in one embodiment, the ports  34  positioned in the upper-right quadrant may each be formed with a uniform diameter that is larger than a uniform diameter of each of the ports  34  positioned in the upper-left quadrant. In another embodiment, the ports  34  in one or more of the staggered rows may be formed with diameters that progressively increase in circumferential directions, about the device  10 , advancing toward and into the upper-right quadrant, which diameters thus progressively decrease in circumferential directions, about the device  10 , advancing out of and away from the upper-right quadrant. In yet another embodiment, if desired, the axial spacing of the ports  34  may be varied. For example, the axial spacing may progressively increase or decrease along a length of the ported section of the device  10 . 
     Persons skilled in the art will appreciate that the ports  34  may be provided on the body of the device  10  in various arrangements and with various circumferential spacings and diameters in addition to those shown and described herein. Important to the present invention according to the various embodiments, however, is that the effective porting of the upper-right quadrant of the device  10  exceeds that of the upper left-quadrant, or that the effective porting of the upper-right quadrant exceeds that of any of the other three quadrants. In this manner, the ports  34  provided on the upper-right quadrant of the device  10  may direct a greater volume of propulsion gases therethrough than each of the upper-left quadrant, the lower-left quadrant, and the lower-right quadrant when the firearm is discharged. 
     Referring now to  FIG. 7 , as well as  FIGS. 1 and 4 , another feature of the present invention may include lateral intake ports  42 . These intake ports  42  are positioned toward the rear of the compensator  10  body to provide fluid communication between the atmosphere outside the device  10  and a rear portion of the inner chamber  24  at a position immediately forward of the muzzle of the barrel  12 . The intake ports  42  may be angled relative to the central axis  16 , as shown at “c,” to enhance draw of outside air into the inner chamber  24  (such as by the Venturi effect) as high velocity propulsion gases exit the bore  18  into the inner chamber  24  and outwardly through the radial ports  34  or the forward outlet opening  22 . The angle “c,” for example, may be about 45 degrees to enhance draw from the rear of toward the front in the direction of gasses exiting the bore  18 . Drawing in oxygenated air through the intake ports  42  can enhance burning of any residual propellant powder and cooling of the propulsion gases prior to their expulsion through the radial ports  34 . Although two intake ports  42  are shown in the illustrated embodiment, any desired number may be used. 
     Although the embodiment illustrated and described above is in the form of an asymmetric compensator  10  attached as a separate unit to a firearm barrel  12 , alternatively the device  10  may integrally formed with the barrel  12  by forming ports in the muzzle end of the barrel  12 , the ports penetrating through an exterior surface of the barrel  12  and into the bore  18 . Important to the present invention in such an embodiment is that the size and/or spacing of the ports provides increased gas flow in the upper-right quadrant of the ported section of the barrel  12 , as compared to that provided by ports in the upper-left quadrant of the ported section of the barrel  12 , as similarly described above. 
     While one embodiment of the present invention has been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. Therefore, the foregoing is intended only to be illustrative of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended to limit the invention to the exact construction and operation shown and described. Accordingly, all suitable modifications and equivalents may be included and considered to fall within the scope of the invention.