Patent Publication Number: US-10317163-B2

Title: Adjustable stabilizer assembly for rifle

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Applicant claims the benefit of Provisional Patent No. 62/499,046, filed on Jan. 13, 2017 by the same inventor. 
    
    
     I. BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     A rifle stabilizer assembly attaching to a front stock of a rifle provides an assortment of stabilizing elements to enhance the shooting potential of a rifle, the assembly providing a stabilizer bar attached to the underside of a front rifle stock, a barrier block attachment, a bipod adapter attachment and a tripod adapter attachment, each attachment selectively chosen by a shooter as appropriate for a selected shot while in competition, hunting or combat. 
     2. Description of Prior Art 
     A preliminary review of prior art patents was conducted by the applicant which reveal prior art patents in a similar field or having similar use. However, the prior art inventions do not disclose the same or similar elements as the present rifle stabilizer assembly, nor do they present the material components in a manner contemplated or anticipated in the prior art. 
     It is known in the art that certain fixed mounting systems exist, providing for mounting systems to a rifle that compose rails. These include Picatiny and Weaver systems, which employ recoil grooves with a similar profile mounted to a front stock of a rifle for attachment of a bipod for long range shooters. They provide a rail with specific grooves of width and depth and mount a bipod, with the bipod including grooved channels which accept the rail and provide for recoil during the act of shooting. The is no fixed connection between the rail and the bipod mounting bracket. Another system known to shooters is the “Arca Rail” system and Arca rail clamp, together called and Arca-Swiss interface, for mounting cameras to tripods, which has been adapted for rifle mounting. Other known mounting systems include Keymod, M-Lok, Hkey, AI Keyslot and UTT/Anschutz rails. 
     With regard to prior art patents, a first patent, U.S. Pat. No. 7,856,748 to Mertz, provides a bipod support and mount for a firearm, providing a front leg support with two extending legs, with the leg support including two bore within which the two bipod legs attach by a respective ball joint. A ball is mounted to a rifle stock which mounts a ball mount receiver to receive the ball. In certain embodiments, a leg keeper or a band strap are also included toward the trigger along the front stock to squeeze the legs under the front stock when not in use. A similar retractable bipod system is demonstrated in U.S. Pat. No. 7,770,320 to Bartak, which provides a stock mounting body member attaching to an internally threaded opening, provided in most rifles for attaching a front end of a swivel mounted strap. The stock mounting body member includes a pair of parallel bores which provide for containment of a pair of bipod legs, which are pulled out of the bores, each leg defining a ball that installs within sockets formed at each bore opening. A third prior art patent application, U.S. Patent Application No. 2008/0307689 to Dotson, provides a replacement front stock for a rifle which includes a forearm chamber within a stock forearm, at least one frame member secured within the forearm chamber and a leg slidingly attached to the frame member at a pin, the leg capable of being in a fully stored position being generally within the forearm chamber, or being fully deployed in a position in which the leg is allowed to slide along the frame member out of a forearm chamber, pivot about a pin into a position which is generally perpendicular to the frame member and barrel to interact with a surface to support and steady the rifle. There is shown two parallel formed slots in each side. 
     None of the prior art indicates a bar rail defining a linear dovetail mechanism, installation of one or more barrier blocks within the dovetail mechanism selectively locking at least one locking pin elevated within one of a plurality of evenly spaced upper lock pin indents, allowing for independent selective placement of each barrier block while allowing a degree of rotational manipulation of each barrier block while locked into position within the bar rail, installation of a bipod mounting member within the same bar rail, with the bipod mounting member upwardly extending a dovetail extension with at least one locking pin selectively engaging at least one of the plurality of evenly spaced upper locking pin indents and extending a lower bipod mounting base, or a tripod mounting member upwardly extending a dovetail extension with at least one locking pin selectively engaging at least one of the plurality of evenly spaced upper locking pin indents and extending a lower tripod mounting base, all of them providing for the engagement and release of the respective locking pin by a manual pin locking means, for installation and removal of each barrier block, bipod mounting member or tripod mounting member. 
     II. SUMMARY OF THE INVENTION 
     Accurate long range rifle shooting requires stability of both the front and rear of the rifle when aiming and firing. While some choose to fire without any support, others who desire more accuracy, especially at long range, employ supports at the rear stock, the front stock or sometimes, both the front and rear stocks contemporaneously. Most common is use of a bipod for prone shots, tripods for standing shots, front stabilizing support aided by a barrier, sandbags resting on flat surfaces underneath the rifle, or simply resting the arms of the shooter on a surface. 
     The current barrier stabilizer assembly provides a slide bar mounting to the underside of the front stock of a rifle, the slide bar defining a lower linear dovetail slot or expansion, at least two adjustable width sliding barrier blocks having a variable degree of radial rotation, a bipod mounting member adapted to secure a bipod below the front of the rifle or a tripod mounting member adapted to secure the rifle upon a tripod stand. An upper surface of the slide bar adapts to, is embedded within or incorporated into the factory front stock of a rifle and is attached by at least two screws. 
     Each barrier block is respectably adjustable at a selected location along the length of the slide bar and with a selected distance between each barrier block. The bipod mounting member is also adjustable along the length of the slide bar and is adapted to provide attachment for a lower bipod. The tripod mounting member is also adjustable along the length of the slide bar and is adapted to provide attachment for a lower tripod. 
     Each barrier block, bipod mounting member and tripod mounting member extend an upward dovetail extension adapted to slide within the linear dovetail slot of the slide bar, with at least one upwardly extending lock pin engaged and released by a manual pin locking means, with each lock pin engaging at least one selected upper lock pin detents among a plurality of evenly spaced and aligned upper lock pin detents located in a lower surface of the slid bar within the lower linear dovetail slot, which secure each barrier block, bipod mounting member or tripod mounting member at a selected location along the slide bar below the front rifle stock. While the shooter would select the at least two barrier blocks, the bipod mounting member or the tripod mounting member for use, the slide bar would accommodate the installation of all three choices. 
     It is contemplated within the scope of the barrier stabilizer assembly that the slide bar extends a lower dovetail extension, with each barrier block, bipod mounting member and tripod mounting member extending an upper dovetail slot selectively engaging the dovetail expansion of the slide bar, reversing the dovetail expansion and dovetail slot of the previously disclosed embodiment. 
    
    
     
       III. DESCRIPTION OF THE DRAWINGS 
       The following drawings are submitted with this utility patent application. 
         FIG. 1  is a lower view of a rifle and front stock, shown in phantom, with an installed linear bar rail attached to the front stock. 
         FIG. 2  is a top view of a barrier block with phantom lines indicating installation upon the linear bar rail. 
         FIG. 3  is a sectional view of the barrier block along lines  3 / 3  of  FIG. 2 . 
         FIG. 4  is a lower view of two barrier blocks attached within the linear bar rail demonstrating the rotational capacity of the barrier blocks. 
         FIG. 5  is a side view showing engagement of the barrier blocks upon a cylindrical rail. 
         FIG. 6  is a side view showing engagement of the barrier blocks upon a rectangular wall or rail. 
         FIG. 7  is a lower view of the bipod mounting member attached within the linear bar rail. 
         FIG. 8  is a sectional view of the bipod mounting member along section lines  8 / 8  of  FIG. 7 . 
         FIG. 9  is a lower view of the tripod mounting member attached within the linear bar rail. 
         FIG. 10  is a sectional view of the tripod member along section lines  10 / 10  of  FIG. 9 , indicating an unlocked position. 
         FIG. 11  is a sectional view of the tripod mounting member along section lines  11 / 11  of  FIG. 9  indicating a locked position. 
         FIG. 12  is a view of an alternative linear bar rail attached to a front stock of a rifle. 
         FIG. 13A  is a close-up view of the alternative workpiece which integrates with the alternative linear bar rail of  FIG. 12 . 
         FIG. 13B  is a view of an alternative workpiece integrated with the alternative linear bar rail of  FIG. 12 . 
     
    
    
     IV. DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An adjustable rifle stabilizer assembly  10  for attachment to a front rifle stock B of a rifle A or other long gun, as shown in  FIGS. 1-11 , provides for a stabilization of the attached rifle upon a barrier, bipod or tripod stand or other solid structure during shooting. For purposes of this disclosure, a rifle A or other long gun will be collectively referenced as a rifle A, although contemplated for use with a shotgun, black power long gun or other non-handgun firearm. In addition, since the application of the rifle stabilizer assembly  10  is provided for rifles of various sizes, gauges, calibers and dimensions of front stocks, no claim is made to dimension, length or width, thickness or depth within this disclosure other than to generalize them adapted to, imbedded within or incorporated into the various rifles. The rifle stabilizer assembly includes a linear bar rail  20  affixed to a lower surface of a front rifle stock B,  FIG. 1 , one or two barrier blocks  40 ,  FIGS. 2-6 , a bipod mounting member  60 ,  FIGS. 7-8 , or a tripod mounting member  80 ,  FIGS. 9-11 . 
     The linear bar rail  20 ,  FIGS. 1-11 , further comprises an upper surface  22  adapting in contour and dimension to the lower surface of the front rifle stock B,  FIG. 1 , a lower portion  24  defining a linear dovetail slot  26  presenting a first end  27  forming a slot opening  28 ,  FIGS. 1 and 4 , and a second closed end  29 , terminating within but not through the bar rail  20 , the linear dovetail slot  26  further defining an upper slot surface  30  defining a plurality of evenly spaced pin detents  34  and at least two recessed mounting bores  32 ,  FIGS. 1, 10 and 11 , through which respective installation screws  35  are securely installed to secure the linear bar rail  20  to the front rifle stock B. Each pin detent  34  is be defined as a half spherical indentation, a hole, a partial channel or other adaptive indentation which extends above the upper slot surface  30  of the linear dovetail slot  26  in a uniform manner, allowing for the insertion and retention of upward urged lock pins  50 ,  70 ,  90 , later defined herein. Although shown as an elongated rectangle, the shape of the linear bar rail  20  is irrelevant, provided it defines the purpose stated herein. It is best that the linear bar rail  20  is made of a light-weight metal or heavy composite material and that the linear dovetail slot be either cast or milled, depending upon the chosen material composition. The installation screws  35  secured within the recessed mounting bores  34  must extend no further than the upper slot surface  30  and avoid interference with the profile of the linear dovetail slot  26  once installed. 
     Each barrier block  40 , shown in  FIGS. 2-6 , further comprises a flat upper portion  41  extending an oval dovetail expansion  42  defining a flat upper surface  43 , a first barrier surface  44  depending from the flat upper portion  41  perpendicular to the flat upper portion  41 , a second barrier surface  45  depending from the flat upper portion  41  at a reduced angle progressing downward, a lower portion  46  between the first and second barrier surfaces  44 ,  45 , a first side plate  47 , and a second side plate  48 . The first and second barrier surfaces  44 ,  45 , may include a friction enhanced coating or a textured surface, not shown. The oval dovetail extension  42  is inserted within the slot opening  28  and slidable engages the linear dovetail slot  26  of the linear bar rail  20 ,  FIG. 3 . 
     At least one upward urged lock pin  50  is centrally located within the upper surface  43  of the oval dovetail expansion  42  which may be intentionally lowered below the upper surface  43  by a lock pin release means  100 ,  200 ,  300 ,  FIG. 3 , which is situated within the first side plate  47 , the second side plate  48  or both. The placement of the lock pin release means  100 ,  200 ,  300 , is designed to avoid the first and second barrier surfaces  44 ,  45 , to prevent interference and access to these surfaces which are engaged with the barrier when in use and also to prevent accidental disengagement of each barrier block  40  from the linear bar rail  20  during use. Each at least one lock pin  50  defines a rounded cylindrical head  52  which extends above the upper surface  43  of the oval dovetail expansion  42  into a locked position, placing the cylindrical head  52  within a selected pin detent  34  as determined by the user to lock the respective barrier block  40  into a position along the linear bar rail  20  suited for the chosen rifle shot. In addition to the lock pin  50  as disclosed within the drawings and referenced above, the lock pin may be embodied as a ball, a cylinder, a shaped taper, an irregular shape or any shape conforming to the pin detents  34  within the linear bar rail  20 . While at rest, the lock pin  50  is elevated into a locked position and prevented from downward movement until such time as the lock pin release means  100 ,  200 ,  300 , is activated, allowing for the rounded head  52  of the lock pin  50  to be lowered below the upper surface  43  and moved along the linear bar rail  20  or removed from the slot opening  28 . Various embodiments of the lock pin release means  100 ,  200 ,  300 , are further disclosed below. While locked within the linear bar rail  20 , the oval dovetail expansion  42  allows an overall bidirectional axial pivot of each barrier block  20  as indicated in  FIG. 4 , while preventing linear movement of the barrier block  20  in a forward or reverse movement. 
     Examples of the barrier upon which the barrier blocks  20  may be include pipes, fences, a vertical wall or a ledge,  FIGS. 5-6 . One can observe that each barrier block  20  offers two different presenting surfaces, either the second barrier surfaces engaging the pipe,  FIG. 5 , or the two flat front barrier surfaces engaging the vertical wall,  FIG. 6 . It is also contemplated that a single barrier block  20  may be use to prop the rifle above an object with the single barrier block providing a pull-back force against an object, or while being pulled towards the rear to steady a shot. The significance of the rotational capacity of each barrier block  20  provides for the axial adjustment of the barrier blocks  20  allowing the shooter to sight and aim the rifle A to a target while using a stationary and likely immovable barrier for support. This rotational capacity of each barrier block a may provide for an adjustment between 0 and 45 degrees,  FIG. 4 . 
     The bipod mounting member  60 ,  FIGS. 7-8 , further defines a flat upper portion  61  upwardly extending an upper dovetail expansion  62  defining a flat upper surface  63 , a front margin  64 , a rear margin  65  and a lower portion  66  providing a bipod mounting base  67  which provides a location for the mounting of a bipod, the bipod not made part of the present invention. The upper dovetail expansion  62  of the bipod mounting member is inserted within and slidable engage the slot opening  28  and the linear dovetail slot  26  of the linear bar rail  20 ,  FIG. 8 . Unlike the oval dovetail expansion  42  of the barrier block, the upper dovetail expansion  62  of the bipod mounting member  60  provides no rotation once inserted and contained within the dovetail slot  26  of the linear bar rail  20 , but it is contemplated within the scope of the invention that it could, although not shown in the drawing figures. 
     At least one upward urged lock pin  70  is centrally located within the upper surface  63  of the upper dovetail expansion  62  which may be lowered below the upper surface  63  by a lock pin release means  100 ,  200 ,  300 , which is situated within the front margin  64 , the rear margin  65  or both. Placement of the lock pin release means  100 ,  200 ,  300 , is essentially located to prevent interference with the mounting and dismounting of the bipod from the bipod mounting base, which is generally accomplished through a side sliding interaction between the bipod and the bipod mounting member  60 . Each at least one lock pin  70  defines a rounded cylindrical head  72  which extends above the upper surface  63  of the upper dovetail expansion  62  into a locked position, placing the cylindrical head  72  within a selected pin detent  34  as determined by the user to lock the bipod mounting member  60  into a position along the linear bar rail  20  suited for the chosen rifle shot. In addition to the lock pin  70  as disclosed within the drawings and referenced above, the lock pin may be embodied as a ball, a cylinder, a shaped taper, an irregular shape or any shape conforming to the pin detents  34  within the linear bar rail  20 . While at rest, the lock pin  70  is elevated into a locked position and prevented from downward movement until such time as the lock pin release means  100 ,  200 ,  300 , is activated, allowing for the rounded head  72  of the lock pin  70  to be lowered below the upper surface  63  and moved within the linear bar rail  20  or removed from the slot opening  28 . Various embodiments of the lock pin release means  100 ,  200 ,  300 , are further disclosed below. The significance of the lack of rotational capacity of the bipod mounting member  60  as opposed to the rotation of the barrier blocks  20  is that the normal use of a bipod occurs when supporting the rifle on the ground or upon a flat surface, the bipod providing the elevation and support for the shot instead of the stationary barrier. 
     The attaching bipod is an accessory which is intended to be purchased separately and installed upon the bipod mounting member  60 . As mentioned earlier in the specification, bipods provided in prior art and in the marketplace, these include Picatiny and Weaver systems, which employ recoil grooves with a similar profile mounted to a front stock of a rifle for attachment of a bipod for long range shooters. They provide a rail with specific grooves of width and depth and mount a bipod,  FIG. 7 , with the bipod including grooved channels which accept the rail and provide for recoil during the act of shooting. The is often no immovable fixed connection between the rail and the bipod mounting bracket which may allow a certain degree of recoil absorption between the bipod and the bipod mounting member, but it is contemplated that a hard fixed means may also be provided, neither connection shown in the drawing figures. 
     The tripod mounting member  80 ,  FIGS. 9-11 , further defines a flat upper portion  81  upwardly extending an upper dovetail expansion  82  defining a flat upper surface  83 , two lateral portions  84  and a lower portion  86  providing a tripod attaching base  87  which provides a location for the mounting of a tripod, the tripod also not made part of the present invention. The upper dovetail expansion  82  of the tripod mounting member  80  is inserted within and slidable engage the slot opening  28  of the linear dovetail slot  26  of the linear bar rail  20 ,  FIGS. 10-11 . Unlike the oval dovetail expansion of the barrier block  20 , the upper dovetail expansion  82  of the tripod mounting member provides no rotation once inserted and contained within the linear dovetail slot  26  of the linear bar rail  20 , but it is contemplated within the scope of the invention that it could, although not shown in the drawing figures. 
     At least one upward directed lock pin  90  is centrally located within the upper surface  83  of the upper dovetail expansion  82  which may be lowered below the upper surface  83  by a lock pin activation/release means  100 ,  200 ,  300 , which is situated within one or both of the lateral portions  86 . Placement of the lock pin release means  100 ,  200 ,  300 , is essentially located to prevent interference with the mounting and dismounting of the tripod from the tripod mounting base  80 , which is generally accomplished through a side sliding interaction between the tripod and the tripod mounting member  80 . Each at least one lock pin  90  defines a rounded cylindrical head  92  which extends above the upper surface  83  of the upper dovetail expansion  82  into a locked position,  FIG. 11 , placing the cylindrical head  92  within a selected pin detent  34  as determined by the user to lock the tripod mounting member  80  into a position along the linear bar rail  20  suited for the chosen rifle shot. In addition to the lock pin  90  as disclosed within the drawings and referenced above, the lock pin may be embodied as a ball, a cylinder, a shaped taper, an irregular shape or any shape conforming to the pin detents  34  within the linear bar rail  20 . There may also be a locator pin  310  utilized between two upward directed lock pins  90 , with the locator pin  310  not locking within the linear bar rail  20  while the two upward directed lock pins  90  are later locked. While at rest, the lock pin(s)  90  is/are elevated into the locked position and prevented from downward movement until such time as the lock pin release means  100 ,  200 ,  300 , is activated, allowing for the lock pin(s)  90  to be lowered below the upper surface  83  and moved along the linear bar rail  20  or removed from the slot opening  28  into an unlocked position,  FIG. 10 . Various embodiments of the lock pin release means  100 ,  200 ,  300 , are again further disclosed below. 
     The attaching tripod is an accessory which is intended to be purchased separately and installed upon the tripod mounting member  80 . As mentioned earlier in the specification, tripods provided in prior art and in the marketplace, these include the “Arca Rail” system and Arca rail clamp, together called and Arca-Swiss interface, for mounting cameras to tripods, which has been adapted for rifle mounting. Other known mounting systems include Keymod, M-Lok, Hkey, AI Keyslot and UIT/Anschutz rails for attachment of a tripod for long range shooters. They provide a rail with specific grooves of width and depth and mount a tripod, with the tripod including grooved channels which accept the tripod rails. It is contemplated that a hard fixed means may also be provided or one allowing for recoil. 
     In a first embodiment of the lock pin release means  100 ,  FIG. 8 , the upward urged lock pin  50  defines the rounded head  52 , a base  53  and a shaft  54  having a central reduced portion  55  compelled upward by a first spring  56  within a vertical pin bore  49 . The lock pin release means  100  provides a transverse mounted release pin  102  with a depression end  103  and a base end  104  compelled outward by a second spring  108  within a transverse bore  110 , with the depression end  103  extending outward from the first or second side plate  47 ,  48 . The release pin  102  further defines a cylindrical shaft  105 , a central reduced bypass portion  106  and a tapered shaft portion  107 . The lock pin  50  is in a locked position when the release pin  102  is stationary and at rest, with the central reduced portion  55  of the lock pin  50  immovable up or down due to interference of the cylindrical shaft  105  of the release pin  102  being located within the central reduced portion  55  of the lock pin  50 . When the release pin  102  is depressed against the force of the second spring  108 , the release pin  102  is move so that its reduced bypass portion  106  is located within the reduced portion  55  of the lock pin  50 , allowing for the rounded head  52  of the lock pin  50  to be completely lowered below the upper surface  43  of the dovetail expansion  42 , releasing engagement with one of the plurality of pin detents  34  which maintain position of the workpiece (selected from the barrier block  40 , bipod mounting member  60  or tripod mounting member  80 ) within the linear bar rail  20 . The tapered shaft portion  107 , when positioned under the base  53 , provides for partial retraction of the lock pin  50 , and full retraction when the base  53  is located above the reduced central portion  55 . When the lock pin  50  is released, the workpiece  500  can be removed or moved elsewhere within the linear bar rail  20 . This embodiment is most practical for the barrier block  20 . 
     A second embodiment lock pin release means  200 ,  FIG. 3 , the upward urged lock pin  70  defines the rounded head  72 , a base  73  and a shaft  74  compelled upward by a first spring  76  within a vertical pin bore  69 . The lock pin release means  200  provides a transverse mounted release pin  202  with a depression end  203  and a base end  204  compelled outward by a second spring  208  within a transverse bore  210 , with the depression end  203  extending outward from a front or rear margin  64 ,  65 . The release pin  202  further defines a cylindrical shaft  205 , and a central reduced diameter portion  206 . The lock pin  70  is in a locked position when the release pin  202  is stationary and at rest, with the base  73  of the lock pin  70  immovable up or down due to interference contact with the cylindrical shaft  205  of the release pin  202  being located below and in contact with the base  73  of the lock pin  70 . However, when the release pin  202  is depressed against the force of the second spring  208 , the release pin  202  is move so that its reduced portion is located below the base  73  of the lock pin  70 , allowing for the rounded head  72  of the lock pin  70  to be lowered below the upper surface  63  of the dovetail expansion  62 , releasing engagement with one of the plurality of detents  34  which maintain position of the workpiece  20 ,  40 ,  60 ,  500  within the linear bar rail  20 . When the lock pin  70  is released, the workpiece  500  can be removed or moved elsewhere within the linear bar rail  20 . This embodiment is most practical for the bipod mounting member  60 . 
     In yet a third embodiment of the lock pin activation/release means  300 ,  FIGS. 10-11 , one or two upward directed lock pins  90  define the rounded head  92 , a base  93  and a shaft  94  contained within a respective vertical pin bore  89 . This embodiment has no release pin. Instead, an outer threaded shaft  302  within at least one lateral slot  85  between the lateral portions  84  of the workpiece  500 , within which is placed a rotating wheel  304  defining a central threaded bore  305  rotatably engaging the shaft  302 , allowing upward and downward movement of the wheel  304  upon rotation. The rotating wheel  304  further defines an upper surface  306 , which is in contact with the base  93  of the one or two upward directed lock pins  90 . When the rotating wheel  304  is elevated by rotation, the one or two lock pins  90  are moved upward under force into the locked position,  FIG. 11 . When the rotating wheel  304  is lowered by rotation, the one or two lock pins  90  are retracted within the respective vertical pin bore  89  into the unlocked position,  FIG. 10 . The one or two lock pins  90  engage a respective detent  34  within the linear bar rail  20  when compelled upward. In order to avoid damage to the linear bar rail  20  and detents  34  by accidental misalignment of the lock pins  90  and the detents  34 , the spring loaded locator pin  310  may be added along with the lock pins  90  to properly align the lock pins  90  before forcible upward movement to lock the one or two lock pins  90  within the linear bar rail  20 . This embodiment is best suited for the tripod mounting member  80 . It is contemplated that other lock pin release means beyond those disclosed in the first, second and third embodiments of the lock pin release means  100 ,  200 ,  300 , may be formed of the elements found in the three disclosed embodiment in various combinations, as well as others than may provide for the functional capabilities to manually raise and lower the lock pins  50 ,  70 ,  90 , for insertion and movement of the barrier blocks  40 , bipod mounting member  60  or tripod mounting member  80 , within the linear bar rail  20 . 
     It is contemplated within the scope of the barrier stabilizer assembly  10  that an alternative linear bar rail  420  defines an upper surface  422  and a lower portion  424  which extends a lower dovetail extension  426 ,  FIG. 12 , defining a flat lower surface  425 . The alternative linear bar rail  420  presents a first end  427  and a second end  429 , the alternative linear bar rail is affixed to, imbedded within, or incorporated into the front rifle stock,  FIG. 12 . Within the flat lower surface  425  of the lower dovetail extension  426  are a plurality of evenly spaced pin detents  434 . Each pin detent  434  is be defined as a half spherical indentation, a hole, a partial channel or other adaptive indentation which extends into the flat lower surface  425  of the lower dovetail extension  426  in a uniform manner. 
     Applying the alternative linear bar rail  400  to the present rifle stabilizer assembly  10  would require modifications to the barrier block  40 , bipod mounting member  60  and tripod mounting member  80 . These three attachments, once again, will be generically referenced as an alternative workpiece  500  for this portion of the specification, drawings and claims. Each workpiece  500 , shown in  FIGS. 13A-13B , defines an upper flat portion  541  forming an inner upper dovetail slot  542  which is capable of slidably engaging the lower dovetail extension  426  of the alternative linear bar rail  420 , with each workpiece  500  further extending the lower portions  546  of each respective workpiece  500 , embodied above as the barrier block  40 , bipod mounting member  60  or tripod mounting member  80 . 
     The upper dovetail slot  542  of each workpiece  500  further defines a flat inner surface  543  defining at least one vertical pin bore  544  containing at least one upwardly urged lock pin  550  defining a rounded head  552  (plus a base, a shaft, a spring) to urge each lock pin  550  upward (in the same manner as the several lock pins  50 ,  70 ,  90  defined above), each workpiece  500  further defining a lock pin activation means  600  preferably located within the lower portion  546  of the respective workpiece  500 . In addition to the lock pin  550  as disclosed within the drawings and referenced above, the lock pin may be embodied as a ball, a cylinder, a shaped taper, an irregular shape or any shape conforming to the pin detents  434  within the linear bar rail  420 . The lock pin activation means  600  may be any of the three embodiments  100 ,  200 ,  300 , as previously defined above or any other embodiment which performs the same function to lock and unlock the lock pin  550  for engagement or movement of the workpiece  500  along the lower dovetail extension  426  of the alternative linear bar rail  420 . 
     Each at least one lock pin  450  extends above the flat inner surface  443  of the dovetail slot  442 ,  FIG. 13A , into a locked position, placing the cylindrical head  452  within a selected pin detent  434  as determined by the user to lock the respective workpiece  500  into a position along the lower dovetail extension of the linear bar rail  20  suited for the chosen rifle shot. Each lock pin  450  is forcibly elevated into a locked position,  FIG. 13B , and prevented from downward movement until such time as the lock pin release means  100 ,  200 ,  300 , is activated, allowing for the rounded head  452  of the lock pin  450  to be lowered into an unlocked position below the flat inner surface  443  and moved along the or removed from the first end  427  or second end  429 . 
     While the adjustable rifle barrier stabilizer assembly  10  has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that changes in form and detail may be made therein without departing from the spirit and scope of the invention.