Patent Publication Number: US-9835400-B2

Title: Integrally suppressed barrel for firearm

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation-in-part of U.S. patent application Ser. No. 14/950,132 filed Nov. 24, 2015, which claims the benefit of priority to U.S. Provisional Application No. 62/096,977 filed Dec. 26, 2014. The foregoing applications are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     The present disclosure generally relates to firearms, and more particularly to barrels with integral silencers or suppressors which reduce the muzzle noise produced by discharging the firearm. 
     Silencers or suppressors generally comprise multiple combustion gas expansion chambers in which the high pressure gas is allowed to partially expand prior to leaving the firearm. The projectile such as a bullet is propelled through the barrel of the firearm and silencer by the combustion gas. In an unsuppressed discharge firearm, the rapid expansion and depressurization of the high pressure gas at the muzzle end of the barrel produces a loud sound referred to as muzzle blast or noise. The partial pre-expansion of gas inside the silencer acts to reduce muzzle noise which is desirable in some circumstances. 
     Silencers are typically configured as separate thread-on assemblies having an outer sleeve and internal sound suppression baffling which are screwed onto the muzzle end of the firearm barrel as a completely removable unit. Some attempts have been made to integrate silencers into the barrel assembly of rifles. However, these units tend to be bulky and cumbersome, thereby creating a barrel assembly that may adversely affect the balance, aiming, and desired slim profile of the barrel and creates a hand held long gun uncharacteristic in dimensions and appearance from a more conventional rifle barrel. 
     Improvements in integrally suppressed firearm barrels are needed. 
     SUMMARY OF THE DISCLOSURE 
     The present invention provides an integrally suppressed barrel for a firearm. In one non-limiting embodiment, the barrel comprises a rear barrel portion defining a breech end and a front barrel portion defining a muzzle end. The silencer components comprises sound suppression baffles arranged in a tubular open ended sleeve of the front barrel portion permanently affixed to and supported by the rear barrel portion of the barrel assembly as a unitary integral part thereof. The baffles have a vertically oblong configuration each including an upper gas expansion chamber aligned with the barrel bore of the rear barrel portion and a lower gas expansion chamber which extends below the barrel&#39;s normal cross section and centerline of the bore to provide additional volume for gas expansion, thereby advantageously improving sound suppression performance. 
     In one embodiment, a barrel adapter is provided which permanently affixes the sleeve to a short rear barrel portion to bring the overall length of the barrel assembly to or above the 16″ minimum length required by the ATF (Bureau of Alcohol, Tobacco, Firearms, and Explosive) for a rifle to not be considered a short barreled rifle (SBR). The baffles are stackable and able to slide into the permanently affixed sleeve (or tube). The baffles are secured in the sleeve via an elongated mounting rod such as without limitation a socket head cap screw which threads into the permanently affixed adapter. Removal of the baffles from the sleeve is possible by the fact that the proximal and rearmost baffle inserted in the sleeve (e.g. named a spacer baffle) is threaded to threadably engage the socket head cap screw. By unscrewing the socket head cap screw from the permanently affixed adapter, but not the spacer baffle, the user can pull on the screw to remove all of the baffles at once which collectively form a self-supported baffle unit outside the sleeve. These stackable baffles frictionally press fit together to seal off the combustion gas byproducts generated by firing the firearm from inside the sleeve, thus allowing for much easier removal of the baffles over most integrally suppressed barrel assemblies on the market today by eliminating fouling and carbon buildup on the inner surface of the sleeve. 
     The integrally suppressed barrel may have a vertically oblong configuration. In one embodiment, the front barrel portion may have a laterally narrow intermediate waist section with a smaller transverse/lateral width than upper and lower portions of the front barrel portion on each side of the waist. 
     According to one aspect, an integrally suppressed barrel for a firearm includes: a front muzzle end and a rear breech end; a rear barrel portion extending adjacent the breech end, the rear barrel portion having a barrel bore defining a projectile pathway and a longitudinal axis; a front barrel portion extending forward from the rear barrel portion to the muzzle end, the front barrel portion permanently affixed to the rear barrel portion and forming a structurally integral part of the barrel with the rear barrel portion; the front barrel portion including a longitudinal internal passageway comprising a tubular upper longitudinal chamber coaxially aligned with the barrel bore and a tubular lower longitudinal chamber, the upper and lower longitudinal chambers in fluid communication through an intermediate waist section having a transverse width less than a transverse width of the upper and lower longitudinal chambers; a plurality of sound suppression baffles longitudinally stacked in the internal passageway of the front barrel portion, the baffles each comprising an upper gas expansion chamber positioned in the upper longitudinal chamber and a lower gas expansion chamber below the upper gas expansion chamber, the upper and lower gas expansion chambers in fluid communication through a laterally constricted throat section interposed therebetween; wherein when the firearm is discharged, combustion gas flows through the baffles from the upper gas expansion chamber, through the throat section, and into the lower gas expansion chamber of each baffle. 
     According to another aspect, an integrally suppressed barrel for a firearm includes: a rear barrel portion defining a rear breech end, the rear barrel portion having an axial barrel bore defining a projectile pathway and a longitudinal axis; an axially elongated outer sleeve extending forward from the rear barrel portion and defining a front muzzle end through which a projectile exits the barrel, the sleeve permanently affixed to the rear barrel portion to form a structurally integral part of the barrel with the rear barrel portion; the sleeve defining a longitudinal internal passageway comprising a convexly curved tubular upper section coaxially aligned with the longitudinal axis and coupled to a convexly curved tubular lower section by an intermediate waist section, the lower section offset from the longitudinal axis; a plurality of sound suppression baffles longitudinally stacked in the internal passageway of the sleeve, the baffles each comprising an upper gas expansion chamber coaxially aligned with the longitudinal axis and a lower gas expansion chamber in fluid communication with the upper gas expansion chamber; a front end cap removably retained to the muzzle end; an elongated mounting rod engaging the front end cap and extending through the lower gas expansion chambers of the baffles, the mounting rod having a rear end threadably coupled to the rear barrel portion; wherein when the firearm is discharged, combustion gas flows from the barrel bore and through the baffles from the upper gas expansion chamber to the lower gas expansion chamber of each baffle. 
     A method for assembling an integrally suppressed barrel for a firearm is provided. The method comprises: providing a rear barrel portion defining an axial bore and longitudinal axis, a hollow outer sleeve permanently affixed to the rear barrel portion to form a structurally integral part of the barrel with the rear barrel portion and having an open distal end, a front end cap, a mounting rod, a spacer baffle, and a plurality of sound suppression primary baffles; releasably attaching a front end of the rod to the front end cap; sliding the plurality of primary baffles onto a threaded rear end of the rod, the primary baffles abuttingly contacting each other; threadably engaging the spacer baffle with the rear end of the rod by rotating the rod, wherein a self-supporting baffle unit is formed; sliding the baffle unit into the outer sleeve through the open distal end; and threadably engaging the rear end of the rod with a threaded socket disposed on the rear barrel portion by rotating the rod; wherein the front end cap is secured inside the distal end of the outer sleeve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of the exemplary embodiments will be described with reference to the following drawings where like elements are labeled similarly, and in which: 
         FIG. 1  is a top perspective view of an integrally suppressed barrel for a firearm according to the present disclosure; 
         FIG. 2  is a bottom perspective view thereof; 
         FIG. 3  is a right side elevation view thereof; 
         FIG. 4A  is a longitudinal cross sectional view thereof; 
         FIG. 4B  is a detailed view from  FIG. 4A ; 
         FIG. 5  is a top plan view of the integrally suppressed barrel; 
         FIG. 6  is a bottom plan view thereof; 
         FIG. 7  is front end view thereof; 
         FIG. 8  is a rear end view thereof; 
         FIG. 9  is an exploded perspective view thereof; 
         FIG. 10A  is a rear perspective view of the barrel adapter of the integrally suppressed barrel of  FIG. 1 ; 
         FIG. 10B  is a front perspective view thereof; 
         FIG. 10C  is a rear end view thereof; 
         FIG. 10D  is a front end view thereof; 
         FIG. 10E  is a right side view thereof; 
         FIG. 11A  is a bottom perspective view of the outer sleeve of the integrally suppressed barrel of  FIG. 1 ; 
         FIG. 11B  is a top perspective view thereof; 
         FIG. 11C  is a rear end view thereof; 
         FIG. 11D  is a front end view thereof; 
         FIG. 11E  is a right side view thereof; 
         FIG. 12A  is a rear perspective view of a spacer baffle of the integrally suppressed barrel of  FIG. 1 ; 
         FIG. 12B  is a front perspective view thereof; 
         FIG. 12C  is front end view thereof; 
         FIG. 12D  is a rear end view thereof; 
         FIG. 12E  is a top plan view thereof; 
         FIG. 12F  is a right side view thereof; 
         FIG. 12G  is a right side cross sectional view thereof; 
         FIG. 13A  is a front perspective view of the primary sound suppression baffles of the integrally suppressed barrel of  FIG. 1 ; 
         FIG. 13B  is a rear perspective view thereof; 
         FIG. 13C  is a front end view thereof; 
         FIG. 13D  is a rear end view thereof; 
         FIG. 13E  is a top plan view thereof; 
         FIG. 13F  is a right side view thereof; 
         FIG. 13G  is a right side cross sectional view thereof; 
         FIG. 14A  is a rear perspective view of the front end cap of the integrally suppressed barrel of  FIG. 1 ; 
         FIG. 14B  is a front perspective view thereof; 
         FIG. 14C  is a left side view thereof; and 
         FIG. 15  is a right side view of a self-support baffle assembly of the integrally suppressed barrel of  FIG. 1 . 
     
    
    
     All drawings are schematic and not necessarily to scale. Parts shown and/or given a reference numerical designation in one figure may be considered to be the same parts where they appear in other figures without a numerical designation for brevity unless specifically labeled with a different part number and described herein. References herein to a figure number (e.g.  FIG. 1 ) shall be construed to be a reference to all subpart figures in the group of figures associated with that number (e.g.  FIGS. 1A, 1B , etc.), unless otherwise indicated. 
     DESCRIPTION OF EMBODIMENTS 
     The features and benefits of the invention are illustrated and described herein by reference to exemplary embodiments. This description of exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation. Terms such as “attached,” “affixed,” “connected,” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Accordingly, the disclosure expressly should not be limited to such exemplary embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features. 
     A non-limiting representative example of a firearm  20  with an integrally suppressed barrel for firearm will now be described with initial reference to  FIGS. 1-9 . As illustrated, the firearm may be rifle in one embodiment; however, in other embodiments the integrally suppressed barrel may be used in other types of firearms including without limitation shotguns, pistols, and revolvers. Accordingly, the invention is not limited in application to any particular type of firearm. 
     Firearm  20  generally includes a receiver  21  for housing trigger-actuated firing mechanism components for discharging the rifle, and a barrel assembly  30  supported by the receiver. A forward portion of the rifle stock defines an elongated forend  22  that provides a handguard for grasping and balancing the barrel portion of the rifle. Forend  22  may be mounted to and supported by the barrel assembly  30  at least in part via threaded fasteners  137  or other attachment methods. The forend may partially enclose and circumscribe at least a portion of the length of the barrel assembly as illustrated in one non-limiting configuration. Forend  22  has a generally U-shaped transverse cross section in one embodiment to complement the arcuately curved and round cross sectional shape of the barrel assembly  30  which is cradled therein. The forend may be made of any suitable material, including wood and plastics. 
     The barrel assembly  30  includes a top  37 , bottom  38 , an open front muzzle end  32 , an open rear breech end  33 , and a longitudinal barrel bore  34  extending between the ends. The bore  34  defines a projectile pathway and a longitudinal axis LA coinciding with the centerline of the bore. A transverse or lateral direction or orientation is defined as being perpendicularly or obliquely angled to the longitudinal axis for convenience of description. The breech end  33  is configured for mounting to the receiver  21  by any suitable method, including for example without limitation a threaded connection, barrel locking lugs, a slip-fit pinned connection, or a rotary coupling as illustrated including a latch mechanism  36  for a barrel assembly of a takedown type rifle as illustrated herein. The mounting method does not limit the invention. The latch mechanism  36  if provided may include an axially slideable cylindrical latch pin  140  with an operating lever  146  for moving the pin forward and rearward. Pin  140  engages a complementary shaped hole in the front of the receiver. A mounting block  147  threadably or otherwise affixed to the bottom of the barrel assembly  30  houses pin and lever. 
     With continuing reference to  FIGS. 1-9 , barrel assembly  30  is comprised of two main components: a standard rear barrel portion  31  which defines the rear breech end  33  and a front barrel portion  40  which defines the muzzle end  32 . The barrel assembly  30  has an overall length L 1  which is preferably at least or above the 16 inch minimum barrel length required by the ATF (Bureau of Alcohol, Tobacco, Firearms, and Explosives) under the National Firearms Act to not be considered a short barreled rifle (SBR) subject to corresponding NFA regulations. In such an embodiment to avoid creating an unduly long and heavy barrel, the rear barrel portion  31  may have a length L 2  less than the 16 inch AFT minimum, and the front barrel portion  40  makes up the difference and has a length L 3  which is sufficient to bring the overall barrel assembly length to 16 inches or above. In order for the front barrel portion  40  to be considered an integral part of the “barrel” for ATF measurement purposes, the front barrel portion is permanently affixed or connected to the rear barrel portion  31  in the factory in a manner which does not permit disassembly by the end user without destroying the barrel. After integration, the front barrel portion forms a structurally integral part with the rear barrel portion  31  as required by the ATF rules. Any suitable ATF compliant permanent fixation method may be used. Per the ATF, a permanent attachment can be accomplished via three different methods: cross-pinning into a blind hole and welding the head of the pin, high temperature silver soldering of the components, and lastly circumferentially welding of the assembly. 
     In a preferred but non-limiting embodiment, the front barrel portion  40  is permanently cross pinned and welded to the rear barrel portion  33  via a non-removable cross pin  35  inserted through lateral holes  123  in sleeve  41 . One hole  123  is a through hole and the other hole is a blind hole. Accordingly, after the pin is installed in the factory, the end user cannot drive the pin with a punch or otherwise disassemble the pinned connection without cutting the barrel assembly. Use of the term “permanent” with respect to the fixation method means that the front barrel portion cannot be separated from the rear barrel portion without physically altering or destructively disturbing the ATF compliant permanent connection between the barrel portions using undue force such as for example cutting, driving cross pins out of their bore, or similar measures. 
     Front barrel portion  40  includes an axially elongated outer tube or sleeve  21  extending parallel to longitudinal axis LA, a plurality of horizontally stacked baffles including a rearmost spacer baffle  50  and plurality of primary baffles  70  removably inserted in the sleeve, a barrel adapter  42  mounted to barrel portion  31  of the barrel assembly  30 , and a distal front end cap  43  removably attached to the sleeve at the muzzle end  32  of the barrel assembly. The proximal or rear end  45  of the front barrel portion  40  is defined as the end which mounts on the front end  39  of the rear barrel portion  33  and receives a projectile therethrough from the barrel bore  34  while the distal or muzzle end  32  of the front barrel portion is defined as the opposite end through which the projectile exits the front barrel portion when the firearm is fired. 
       FIGS. 11A-E  depict the outer sleeve  41  alone in greater detail. Referring to these figures and  FIGS. 1-9 , the outer sleeve  41  has a hollow tubular body including longitudinally-extending opposing sidewalls  100  that define a rear or proximal end  101  (“proximal end” for brevity), a front or distal end  102  (“distal end” for brevity), and a longitudinal internal passageway  46  extending axially between the ends. The ends  101  and  102  may be fully open in one embodiment without any flanges or other inwardly or outwardly radially extending protrusions which simplifies manufacture of the sleeve. The interior surface of the sleeve (e.g. sidewalls  54 ) may be generally smooth from end to end to allow the stack of baffles to readily slide and be fully inserted into the sleeve. The outer surface  29  of the sleeve  41  may be solid in structure (i.e. free of through holes or apertures) and generally plain in one embodiment. In some embodiments, a front sight may optionally be mounted on the sleeve. 
     Sleeve  41  is vertically elongated and oblong in transverse cross section in one embodiment including arcuately curved convex upper and lower sections  103  and  104  separated and joined by a concave intermediate waist section  49 . In one configuration, the waist  49  may preferably be constricted and narrower in transverse/lateral maximum width W 2  than the maximum width W 1  of the upper and lower sections  103 ,  104 . In other possible embodiments, waist section  49  may have the width W 2  as the width W 1  of the upper and lower sections. In cross section, the sleeve  41  therefore generally has a vertically stacked double tubular configuration as both the upper and lower sections each have a tubular shape in three dimensions. 
     The maximum height H 2  of the sleeve  41  (and front barrel portion  40 ) is preferably greater than the maximum width W 1  to maintain a small cross sectional profile to facilitate aiming, carrying, and storing the firearm in addition to aesthetic reasons. In various embodiments, height H 2  is preferably is at least 1.5 times the width W 1 , and more preferably at least 1.8 times width W 1 . In one embodiment, the width W 2  of the waist section  49  is 0.8 time width W 1  or less. The narrow waist section  49  may be formed by opposing longitudinally-extending concave recesses  106  in the outer surfaces of the opposing sidewalls  100 . On the interior surface of the sleeve  41  adjoining each recess  106 , a pair of inwardly and longitudinally-extending opposing protrusions  105  are formed in the internal passageway  46  (best shown in  FIGS. 11C-D ). When the baffles  50 ,  70  are mounted in the sleeve  41 , this supports the baffles and maintains proper orientation of the baffles which resists twisting about the longitudinal axis LA when the firearm is discharged or the front barrel portion is assembled. Advantageously, this further eliminates the need for two baffle mounting rods as in some designs to prevent baffle twist. 
     In one embodiment, the front barrel portion  40  therefore has a corresponding overall vertically oblong shape in transverse cross section (see, e.g.  FIGS. 7, 9, and 11A -D showing sleeve  41 ). The front barrel portion may be considered to have a generally “peanut shaped” cross sectional and front end view configuration, which is created by the shape of the outer sleeve  41  described above. The shape of the sleeve and front barrel portion may be symmetrical in cross section or front end view in one embodiment. Besides the outer sleeve  41 , the baffles  50  and  70 , front end cap  43 , and rear barrel adapter  42  accordingly all have a matching transverse oblong cross sectional shape with narrowed waist which combine to create the overall vertically oblong shape of the front barrel portion  40 . The upper section  103  of the sleeve  41  preferably has a complementary shape and size to the rear barrel portion  31  of the barrel assembly  30  to provide a smooth transition therebetween for both aesthetic and line of sight purposes to facilitate aiming the firearm. The outer radius of the top of the upper section  103  therefore preferably coincides with that of the rear barrel portion  31 . 
     In one embodiment, the front barrel portion  40  has a smoothly contoured and non-polygonal profile in front profile as illustrated. In other possible embodiments, the front barrel portion may have an at least partially angular or polygonal shaped profile. 
     Referring to  FIGS. 1-9 , the longitudinal internal passageway  46  of the front barrel portion  40  includes a tubular upper longitudinal chamber  47  through which the projectile (e.g. bullet/slug) travels and a tubular lower longitudinal chamber  48 . The lower and upper chambers are in fluid communication through the internally open narrow intermediate waist section  49  of the sleeve  41  (and baffles  50 ,  70 ). The upper chamber  47  is therefore essentially a continuation of the barrel bore  34  in rear barrel portion  31  for purposes of the projectile path and coaxially aligned with the bore and longitudinal axis LA. The lower chamber  48  is parallel to and below the upper chamber. Waist section  49  has a transverse width W 2  (measured between the sidewalls) which is less than the transverse width W 1  of the upper and lower chambers  47 ,  48  (measured between the sidewalls) corresponding to the upper and lower sections  103 ,  104  of sleeve  41 . 
     The lower chamber  48  creates additional volume for gas expansion and sound suppression when the baffles are disposed therein. Accordingly, front barrel portion  40  preferably has a maximum height H 2  which is less than maximum height H 1  of the rear barrel portion  31  mounted to the receiver  21 . In operation, combustion gases generated by discharging rifle  20  flow from the bore  34  of the rear barrel portion  31  into the upper chamber  47  of front barrel portion  41  and travel forward through the front barrel portion toward muzzle end  32 . As the gas travels axially through the series of baffles  50  and  70 , a portion of the gases diverge from the longitudinal gas flow path and flow downwards transverse to the longitudinal axis LA through the narrow intermediate waist  49  opening and fill the lower chamber  48 , thereby allowing additional expansion of the gas and concomitant suppression of the muzzle blast. 
     The internal passageway  46  of the sleeve  21  and particularly the central bores or apertures of baffles  50 ,  70  collectively define an upper projectile pathway P through the front barrel portion  40  which extends along the longitudinal axis LA in a direction from the proximal end  101  to distal end  102  of the outer sleeve  41 . Pathway P is shown as a directional arrow to indicate the direction followed by a projectile from the barrel bore  34  when the firearm is discharged. 
     The barrel adapter  42  is configured and constructed to facilitate permanently mounting the adapter and sleeve  41  to the rear barrel portion  31  of the barrel assembly  30  in one of the ATF compliant methods described herein to create an overall barrel assembly length that meets or exceeds the ATF minimum barrel length requirements for non-short barreled rifles. Barrel adapter  42  is shown in further detail in  FIGS. 10A-E . Referring to these figures and  FIGS. 1-9 , the barrel adapter  42  includes a front end  112 , rear end  113 , upper section  110 , and lower section  111  joined by a narrow waist section  114  therebetween. The upper and lower sections  110 ,  111  may be tubular in shape having a complementary configuration to the rear portions of the upper and lower sections  103 ,  104  of the outer sleeve  41 . An internal through passage  115  extends between the ends of the upper section  110  defining a projectile pathway which is coaxially aligned with barrel bore  34  and longitudinal axis LA. The lower section  111  includes a front recess  116  and rear recess  117  separated by a division wall  119  which defines a threaded socket  118 . Mating threaded rear end  121  of baffle mounting rod  44  screws into socket  118  to rotatably and removably couple the rod to the adapter for mounting the baffles  50 ,  70 , as further described herein. 
     To create a permanent ATF qualifying coupling and integrated structure as described above, a laterally extending smooth bore  120  is formed through the sidewalls of the barrel adapter  42  which receives a cross pin  35 . Cross pin  35  extends transversely through the bore  120  and a concentrically aligned laterally extending smooth bore  122  in the rear barrel portion  31  of barrel assembly  30  to secure the pin  35  in place, thereby locking the barrel adapter  42  to the rear barrel portion. This is a first step. 
     To complete the permanently joined ATF qualifying assembly, the rear end of the sleeve  41  is in turn permanently mounted to the barrel adapter  42  such as via any suitable ATF compliant permanent joining method already described herein. In one embodiment, sleeve  41  is pinned to the barrel adapter  42  using cross pin  35  which is insertably driven through a pair of transversely spaced apart laterally open holes  123  in the sidewalls in rear end of the sleeve  41  (see, e.g.  FIGS. 11A , B, and E). One hole  123  extends completely through the sidewalls of the sleeve and the opposing hole  123  is a blind hole as required by the ATF having an inside open end and an outer closed bottom that does not penetrate the sidewall. The blind hole is accessible only from the interior of the sleeve to the cross pin  35 . One installed, the pin  35  is welded to the sleeve  41  and cannot be removed. In one embodiment, the end of the pin may be ground and is preferably flush with the outer surface of the sleeve  41 . Because of the far side blind hole  123 , a punch is precluded from being used to attempt drive the pin back out and break the weld. Other permanent ATF compliant methods of attaching the barrel adapter  42  and sleeve  41  to the rear barrel portion  31  as already described herein may be used in other embodiments. The method used does not limit the invention. 
     With additional reference to  FIGS. 10A-C , the distal front end cap  43  is generally vertically oblong in shape and has a plate-shaped body comprising front end  130  and opposite rear end  131 . End cap  43  includes a vertical end wall  132  with a forwardly open recessed receptacle  135  at the bottom of which is lower aperture  133  for receiving baffle mounting rod  44  therethrough. An enlarged head  136  of the mounting rod is received in the receptacle, thereby flushly mounting the head with the front end  130  of the end cap  43 . The head  136  may have a hex shaped or other shaped tool socket  172  which opens forward for receiving a complementary configured end of a tool therein (e.g. hex key, screwdriver, etc.) for rotating the mounting rod when securing the baffle assembly inside the barrel. In one embodiment, receptacle  135  may be formed in a tubular extension extending rearwards from end wall  132  of the end cap. 
     An upper exit aperture  134  in front end cap  43  is in fluid communication with the internal passageway  46  of the front barrel portion  40 . Aperture  134  is sized to allow a fired projectile such as a bullet or slug to pass therethrough. Exit aperture  134  is coaxially and concentrically aligned with the longitudinal axis LA and barrel bore  34 . In one non-limiting embodiment, the exit aperture  35  continues and opens rearward into a tubular extension disposed in passageway  46  inside the end cap  43 . The tubular extension  34  may be integrally formed with end wall  38  in one embodiment and extends rearwardly from the wall towards the breech end  33  of barrel assembly  30 . 
     In one embodiment, front end cap  43  further includes a rear facing raised lip  141  protruding rearwards from a rear surface of the end cap. The lip  141  is configured and dimensioned for insertion into the forward-most baffle  70  (see, e.g.  FIGS. 4A and 4B ). The raised lip extends around the entire perimeter of the end cap  43  and is spaced slightly inwards from the peripheral edges of the cap (best shown in  FIGS. 14B and 14C ) to create a peripheral shoulder  142  from receiving the front distal end  102  of the outer sleeve  41 . The shoulder  142  abuttingly engages the forward-most baffle  70 , thereby helping secure the baffles in place and apply a compressive force to the stack of baffles  50 ,  70  when the baffle mounting rod  44  is tightened. 
     Mounting rod  44  (best shown in  FIGS. 4A-B  and  9 ) is axially elongated having a smooth shaft  137  which extends from the front end cap  43  through the stack of baffles  50  and  70 , and into the rear mounting adapter  42 . In one embodiment, mounting rod  44  may be in the form of a cap screw with threaded rear end  121 , long shaft  44 , and front diametrically enlarged head  136  having a forward facing tool recess accessible when the baffle assembly is installed in the front barrel portion  40  for rotating the rod. In other embodiments, different methods may be used for securing the baffles in the front barrel portion of the barrel assembly  30 . Mounting rod  44  preferably has an axial length (measured along the longitudinal axis LA) which is longer than the assembled length of the stacked baffles, for reasons which will become evident. 
     For created a flush and smooth transition between the outer sleeve  41 , barrel adapter  42 , and rear barrel portion  31  of the barrel assembly  30 , a series of stepped shoulder may be provided. The barrel adapter  42  includes a circumferentially extending shoulder  138  on an exterior surface which abuttingly engages the rear end  101  of sleeve  41 . Similarly, the front end  39  of rear barrel portion  31  includes a circumferentially extending shoulder  139  on an exterior surface which abuttingly engages the rear end  113  of barrel adapter  42 . This arrangement forms a smooth profile and transition between the outer sleeve  41 , barrel adapter  42 , and rear barrel portion  31 . 
     The rearmost spacer baffle  50  and plurality of primary baffles  70  will next be described. 
     Referring now to  FIGS. 4A-B  and  13 A-G, spacer baffle  50  generally comprises a vertically stacked dual tubular body including a front end  58 , rear end  59 , and a tubular upper section  51  coupled to a tubular lower section  52  by a laterally narrow waist section  53  therebetween. Waist section  53  has a smaller width than the upper or lower sections. Upper and lower sections  51 ,  52  each respectively define a corresponding internal upper gas expansion chamber  54  and lower gas expansion chamber  55  each having a generally tubular configuration and related round cross section corresponding to the baffle body, as illustrated. The upper and lower gas expansion chambers  54 ,  55  extend from the front end  58  to rear end  59  and through the ends. The narrow waist section  53  is internally open allowing the upper gas expansion chamber  54  to fluidly communicate with the lower gas expansion chamber  55  for transferring a portion of the combustion gases therebetween. The lower gas expansion chamber  55  therefore creates additional internal volume for combustion gas expansion below the upper longitudinal chamber  47  inside the front barrel portion sleeve  41  and the projectile pathway therethrough. 
     In one embodiment, the rear end  59  of the spacer baffle  50  may include rear wall  60  adjacent to the upper and lower gas expansion chambers  54 ,  55 . The front end  58  may be completely open for receiving a rear portion of the rearmost primary baffle  70  therein as further described herein. A first top rear aperture  57  is formed in the rear wall  60  which fluidly communicates with the upper gas expansion chamber  54 . Aperture  57  may be diametrically smaller than the diameter of the upper gas expansion chamber  54  in one configuration. A second rear bottom aperture  56  is formed in the rear wall  60  which fluidly communicates with the lower gas expansion chamber  55  forming a through hole. Aperture  56  may be diametrically smaller than the diameter of the lower gas expansion chamber  55  in one configuration. Aperture  56  may be threaded in one embodiment for rotatably engaging the threaded rear end  121  of the baffle mounting rod  44 , as further described herein. Apertures  56  and  57  may each be round. Preferably, the top rear aperture  57  has a diameter at least as large as or larger than the barrel bore  34 . Baffle  50  may made of any suitable preferably metallic or non-metallic material. 
     Spacer baffle  50  has a complementary cross sectional shape to the cross sectional shape of the outer sleeve  41 . Preferably, the spacer baffle  50  is sized slightly smaller than the sleeve  41  to allow the baffle to slide therein. When the spacer baffle  50  is installed in the front barrel portion  40  of the barrel assembly  30 , the rear wall  60  of the baffle abuttingly engages the front  39  of the rear barrel portion  33  and the top rear aperture  57  becomes concentrically and coaxially aligned with the barrel bore  34  for receiving a projectile therethrough. A portion of the rear wall  60  of the baffle  50  which defines the top rear aperture  57  may form a rear protrusion  61  which extends rearward from the baffle beyond the rear wall adjoining the rear bottom aperture  56 . The protrusion  61  defines an annular shoulder  62  which abuttingly engages a mating annular seat  143  on the front end  144  of the barrel adapter (see also  FIGS. 4B and 10B ). This arrangement helps lock the spacer baffle  50  into correct position against the front end  39  of the rear barrel portion  31  of the barrel assembly  30 , thereby creating a close fit. 
     The primary baffles  70  will now be described with initial reference to  FIGS. 4B and 13A -G. In one non-limiting embodiment illustrated herein, baffles  70  may be configured similarly to the skewed cone design disclosed in U.S. patent application Ser. No. 14/950,132 filed Nov. 24, 2015, which is incorporated herein by reference in its entirety. Modifications are made to adapt the baffle for use in the present integrally suppressed barrel design and provide the additional lower gas expansion chambers and new mounting system. 
     Primary baffles  70  may each be configured similarly and generally comprise a vertically stacked dual tubular body including an front end  160 , partially closed rear end  161 , and a convexly curved tubular upper section  71  coupled to a convexly curved tubular lower section  163  by an internally open and laterally narrow concave waist section  164  interposed therebetween. Waist section  164  has a smaller lateral/transverse width than the upper or lower sections in a similar manner to the outer sleeve  41  of the front barrel portion  40 . Upper and lower sections  71 ,  163  each respectively define a corresponding internal upper gas expansion chamber  73  and lower gas expansion chamber  166  each having a tubular configuration and related round cross section corresponding to the baffle body, as illustrated. The upper and lower gas expansion chambers  73 ,  166  extend from the front end  160  to rear end  161  and through the ends. The narrow waist section  164  is internally open allowing the upper gas expansion chamber  73  to fluidly communicate with the lower gas expansion chamber  73  for transferring a portion of the combustion gases therebetween. The waist section  164  defines a laterally constricted throat opening T 1  between the upper and lower gas expansion chamber that acts like a converging/diverging-nozzle. The throat opening T 1  is smaller in width than the width (i.e. diameter) of the upper and lower gas expansion chambers  73 ,  166 . The lower gas expansion chamber  73  advantageously creates additional internal volume for combustion gas expansion below the upper longitudinal chamber  47  of sleeve  41  and the projectile pathway. 
     It bears noting that in other possible alternative embodiments, the constriction in waist section  164  may instead be formed by opposing inwardly extending protrusions formed on the interior surface of the baffle  70 . In such embodiments, both the waist section  49  of outer sleeve  49  and waist section  164  of baffle  70  may have the same lateral width as the upper and lower sections of the sleeve and baffles forming substantially straight waist sections between their respective sides. 
     In one embodiment, the rear end  161  of the spacer baffle  50  may include rear wall  167  adjacent to the upper and lower gas expansion chambers  73 ,  166 . The front end  160  may be completely open for receiving a rear portion of the next baffle  70  therein as further described herein. A lower mounting aperture  168  is formed in the rear wall  167  which fluidly communicates with the lower gas expansion chamber  166 . Rear wall  167  may be vertically flat in one embodiment which contrasts with the arcuately concave shape of the rear wall concave wall segment  78  surrounding the flat face and central aperture  75 . Aperture  168  may be diametrically smaller than the diameter of the lower gas expansion chamber  166  in one configuration. Aperture  168  may have a smooth bore in one embodiment for allowing the baffle mounting rod  44  to slide therethrough, as further described herein. Aperture  168  may be round and sized slightly larger in diameter than the diameter of the mounting rod  44 . Baffles  70  may made of any suitable preferably metallic or non-metallic material. 
     Each primary baffle  70  has a complementary cross sectional shape to the cross sectional shape of the outer sleeve  41  of the front barrel portion  40 . Preferably, each baffle  70  is sized slightly smaller than the sleeve  41  to allow the baffle to slide therein. When the plurality of baffles  70  are installed in the front barrel portion  40  of the barrel assembly  30 , a portion of the rear wall  167  of the rearmost baffle  70  abuttingly engages the front end  58  of the rear spacer baffle  50 . 
     Primary baffle  70  defines a rear extension  169  that defines rear wall  167  of the baffle body. In one embodiment, the rear extension  169  includes an asymmetrically shaped upper hollow cone  72  protruding rearwardly from the tubular upper section  71  and a partially cylindrical lower portion  170  protruding rearwardly from the tubular lower section  163 . Cone  72  is formed by a complexly curved upper portion of the rear wall  167 . The interior open upper gas expansion chamber  73  extends rearwards insides the cone  72 . Similarly, the interior open lower gas expansion chamber  166  extends rearwards inside lower portion  170 . In one embodiment, the cone  72  is formed integrally with the baffle body and tubular upper section  71  of the baffle  70  as a unitary structural part thereof. In other embodiments, the cone may be a separate component attached to sleeve via any suitable means such as welding, brazing, soldering, adhesives, fasteners, etc. in part depending on the material selected for the baffle. 
     Tubular upper section  71  may define a majority volumetric portion of the forwardly open upper gas expansion chamber  73  in contrast to the open interior of the rear extension  169 . Chamber  73  is sized for insertion of the cone  72  of the next adjacent forward primary baffle  70  at least partially therein through open front end  160  of the baffle, as best shown in  FIGS. 4A and 4B . The mounting sleeve  71  has a distal edge  79  which defines the front end  74  of the baffle and a proximal edge  80  which adjoins and from which the cone  72  extends axially towards the proximal end  101  of the outer sleeve  41 . The distal edge  80  has a stepped configuration in one embodiment forming a shoulder  80   a  at the transition between the rear extension  169  and tubular upper and lower sections  71 ,  163  of the baffle. Shoulder  80   a  defines a rear facing abutment surface for engaging the proximal edge  79  of the next adjacent rearward primary baffle  70  when the baffle stack is assembled, or in one case of the distal edge  80  of rearmost baffle  80  the abutment surface engages the front end  58  of the spacer baffle  50 . The stepped configuration between the rear extension  169  (which defines cone  72  and lower portion  170 ) and front upper and lower tubular sections  71 ,  163  slightly recesses the rear extension around its perimeter which forms a frictional press fit into the distal edge  79  of the next rearward adjacent baffle to create a gas tight seal and self-supporting assembled baffle array which does not require the outer sleeve  41  for support outside of the sleeve (see, e.g.  FIG. 14 ). This creates a primary pressure retention boundary or barrier for retaining the combustion gas pressure which does not rely on the secondary pressure retention boundary or barrier formed by the outer sleeve  41 . The rearmost primary baffle  70  forms a frictional press fit also with the distal front end  58  of the spacer baffle  50  in a similar manner. Note that press fitting between the primary baffles  70  and spacer baffle  50  collectively create a sealed internal volume to advantageously prevent or minimize gas out-leakage and carbon/lead from building up on the inside of the outer sleeve  41 , thereby advantageously reducing maintenance and cleaning. 
     Cone  72  includes an internally open base end  81  connected to upper section  71  and a free terminal end  82  defining a rear prominence. Cone  72  has a complex asymmetrical and skewed compound shape in one embodiment combining an axially-straight part-cylindrical wall segment  77  extending rearward from upper section  71  and an arcuately curved concave wall segment  78  adjoining wall segment  77 . Wall segment  77  has a partial cylindrical configuration (hereafter “partial cylinder wall segment” for brevity) and an axial length shorter than the partially cylindrical lower portion  170  of the rear extension  169  adjoining the lower section  163  of the baffle. The axial length of the wall segment  77  gradually increases along arcuate contour lines  84  formed at a transition between adjoining portions of the partial cylindrical wall segment  77  and concave wall segment  78  moving downward along each of the lateral sides of the cone  72 . Accordingly, an arcuate contour line  84  is present on both lateral sides of the cone  72 . When positioned in the front barrel portion outer sleeve  41 , the partial cylindrical wall segment  77  forms a portion of the entire cone  72  which is disposed adjacent and closest to the interior surface of the outer sleeve  41 . 
     The concave wall segment  78  of cone  72  extends obliquely to and from the axially-straight partial cylindrical wall segment  77 . The concave wall segment  78  of cone  72  defines an oblong upper central aperture  75  which receives a projectile therethrough from the barrel bore. Central aperture  75  is coaxially and concentrically aligned with the longitudinal axis LA and barrel bore  34 , respectively. Central aperture  75  has a smaller open area than the inside diameter of the open base end  81  of the cone  72 . The vertical major axis of central aperture  75  is longer than a horizontal minor axis similar to an ellipse. Preferably, the open area of central aperture  75  presents a rearward projected vertical diameter that matches or is slightly larger than the diameter of the barrel bore  34  to receive a projectile therethrough. 
     The central aperture  75  of primary baffle  70  is obliquely arranged and oriented to the longitudinal axis LA of the barrel assembly  30  (see, e.g.  FIGS. 4A-B ). Accordingly, an acute and oblique angle is formed between longitudinal axis LA and the angled plane in which the central aperture  75  substantially lies. Aperture  75  is angled to face generally both rearwards and upwards forming the hood or overhang below the aperture as shown. In operation, the hood of the aperture and concave configuration of the cone  72  encourages a substantial portion of the combustion gasses to spill over the wall of the cone and flow downwards from the upper gas expansion chamber  73  through the narrow waist  164  and into the lower gas expansion chamber  166  of the baffle  70 . This path of least resistance creates a strong cross-jetting that slows the progression of the gasses traveling in-line with the central aperture  75  to fill the lower gas expansion chamber. This increases the sound deadening performance of the integrally suppressed barrel. 
     For an arbitrary reference system to facilitate description, the upper aperture  75  defines a horizontal aperture centerline Cl which defines a horizontal reference plane Cp which includes centerline Cl. Centerline Cl is coaxial with the longitudinal axis LA of the barrel assembly  30  when mounted therein and bisects the tubular upper section  71  into upper and lower halves Uh and Lh. The concave wall segment  78  defines a rear face of the baffle  70  which is divided into a concave upper half section  78   a  defined above the centerline Cl and reference plane Cp, and a concave lower half section  78   b  defined below the centerline Cl and horizontal reference plane Cp. The shape and axial length of the upper and lower half sections is different giving the upper and lower half sections a different side profile as illustrated in the side and side cross-sectional views of the baffle  70 . The cone  72  is therefore asymmetrical in shape. The lower half section  78   b  protrudes axially rearward towards rear or proximal end  101  of front barrel portion  40  farther than the upper half section  78   a . Accordingly, the lower half section  78   b  of the concave wall segment  78  has portions below the terminal end  82  of the baffle  70  which are spaced farther rearward than and apart from the tubular upper section  71  of baffle than any portions of the upper half section  78   a  in the illustrated embodiment. 
     The upper and lower half portions  78   a ,  78   b  of the concave wall segment  78  collectively define the oblong upper central aperture  75 . A rear prominence on the lower half portion  78   b  of the cone concave segment adjacent central aperture  75  defines a leading edge  83  of the aperture and a trailing edge  86  of the aperture is defined by the upper half portion  78   a . In the orientation of silencer  20  as shown in  FIGS. 11F and 11G , the leading edge  83  is a top edge and trailing edge  86  is a bottom edge of central aperture  75 . Leading edge  83  projects farther rearward than the trailing edge  86  such that a projectile entering the central aperture  75  from the barrel bore  34  of rear barrel portion  31  after discharging the firearm first encounters the leading edge. The leading edge  83  thus creates a cantilevered hood below the central aperture  75  forcing a portion of the gas not traveling directly through the aperture upwards around the aperture and then downwards along the rear face of the cone towards the lower gas expansion chamber  166 . A concavely sloped and double wedge shaped prominent ridge  88  extends downward from the leading edge  83  of central aperture  75  to the lower mounting aperture  168  where concave right and left faces  171   a ,  171   b  of the lower portion  78   b  of concave wall segment  78  meet (see, e.g.  FIGS. 13B, 13F, and 13G ). Faces  171   a ,  171   b  are on opposite sides of ridge  88  and each may be wedge shaped having a broader top than bottom. 
     In some embodiments, an upper lower minor portion  75   a  of the central aperture  75  may have a smaller lateral width which is less than the diameter of the barrel bore  34  so that the projectile does not pass through this portion. Conversely, the lower major portion  75   b  of the central aperture  75  having a lateral width larger than the minor portion  75   a  has a lateral width the same as or larger than the barrel bore  34  to allow passage of a projectile therethrough. The upper minor portion  75   a  adds extra open space above the projectile as it is passing through the central aperture  75  to permit combustion gas cross-jetting to initiate simultaneously which enhances sound suppression performance. 
     The cone  72  of each primary baffle  70  may be considered to be essentially shaped like an asymmetric skewed cone. The axially shorter upper half section  78   a  section of the baffle cone segment  78  is designed to ramp the combustion gas pressure away from and around the central aperture  75  to gather at the lowest point on the upper half section  78   a  of the cone segment against the baffle face. As the combustion gas pressure builds enough to “spill” over the oblong rim of the cone segment that defines the aperture  75  and flows into the aperture through the upper minor portion  75   a , this causes gas cross-jetting into the next forward baffle upper gas expansion chamber  73 . 
     Cross-jetting is extremely effective at disrupting the high speed combustion gasses traveling along the bore-line (i.e. longitudinal axis LA coaxial with central aperture  75 ), which if left alone would escape out of the suppressor at high pressures, thus creating a loud report. The gasses need to be slowed down to give them time to expand and cool. The cross-jetting of the rearmost first primary baffle  70  causes the gasses to divert from the bore-line, get caught in the next downstream baffle chamber  110 , and then add to the cross-jetting flow of that baffle. Thus, the efficacy of each baffle  70  progressively improves closer to the front distal end  23  of the front barrel portion  40 . The asymmetrically skewed shape of the primary baffle  70  encourages this cross-jetting to occur faster than normal cone shapes. It is advantageous for this cross-jetting effect to occur quickly in order to slow as much escaping gas as possible for improving sound suppression. 
     The primary baffle  70  can be formed by any suitable method. In some fabrication processes, this compound baffle shape may be machined from a single piece of metal bar stock or investment cast to net shape and then finished by appropriate machining techniques. The invention is not limited by the production method(s) used. 
     Although primary baffles  70  have been described which incorporate the foregoing skewed cone design in the projectile pathway of the sound suppression device, the invention is not limited in its applicability to such baffle configurations alone. In other embodiments, numerous baffle variations and alternative shapes may be used including as some examples without limitation plain baffle apertures in a straight or angled baffle face, symmetrical cone designs on the baffle face, and others. Such other designs may be used in the integrally suppressed barrel system and mounting mechanism with equal benefit. 
     A method for assembling the barrel assembly  30  will now be generally described. The method described herein is one of several possible sequential approaches for assembling the integrally suppressed barrel. Accordingly, numerous sequential variations are possible and the invention is not limited to any one approach. 
     The present method comprises initially providing the following unassembled major components of the integrally suppressed barrel system: the rear barrel portion  31 , outer sleeve  41  of front barrel portion  40  a front end cap  43 , spacer baffle  50 , a plurality of primary baffles  70 , rear barrel adapter  42 , and baffle mounting rod  44 .  FIG. 9  shows the baffle mounting system and integrally suppressed barrel in a disassembled condition for reference. 
     The barrel adapter  42  is permanently installed on the front end  39  of the rear barrel portion  31  of barrel assembly  30  as an initial step (if not already installed) using the cross-pinning method already described herein or an alternative permanent fixation method. The outer sleeve  41  is then permanently affixed to the barrel adapter  42  (if not already done so before fixing the adapter to rear barrel portion  31 ) using any of the permanent fixation methods described above. The mounted outer sleeve is now prepared and ready for installing the baffles. 
     In one embodiment, the baffles  50 ,  70  may be pre-assembled onto the rod to produce a self-supporting and self-contained complete baffle assembly or unit in which the baffles are self-retained on the mounting rod  44  without sliding off and manually holding the baffles in place on the rod. Such a completed baffle stack unit is shown in  FIG. 14 . Advantageously, this allows the baffle unit to be simply inserted into or later removed from the outer sleeve  41  as a complete assembly without individually sliding each baffle one at a time into the sleeve in piece meal fashion. This saves assembly/disassembly time for the end user if the baffles are removed periodically for routine maintenance and avoids parts getting lost. 
     The baffle unit may be preassembled by first sliding front end cap  43  onto the rear end  121  of the mounting rod  44  via the lower aperture  133  and then sliding it forward to engage the head  136  of the rod. Aperture  133  is smaller in diameter than the head  136  which prevents the end cap from sliding off. 
     The primary baffles  70  may then be installed on the mounting rod  44  using one of two approaches. In a first approach, the baffles  70  may be slid onto the mounting rod one at a time in a similar manner as the front end cap via the lower mounting aperture  168 . As each baffle is mounted on the rod, it is pressed and locked into the adjoining baffle via a friction fit in the manner as already described above. This interlocked relationship creates a gas tight seal between the baffles. Alternatively in a second approach, the primary baffles may be press fit together to form an interlocked stacked baffle assembly which is self supporting in its own right. The preassembled baffle stack may then be slid onto and along the mounting rod as a unit. Both approaches may be used and the invention is not limited to either one. In either case, the foremost baffle  70  is press fit onto the front end cap  43  via a friction fit in the manner already described herein. 
     Finally, the spacer baffle  50  is threadably engaged with the mating threaded rear end  121  of the baffle mounting rod  44  via threaded rear bottom aperture  56 . This threaded engagement retains the entire stack of baffles  50 ,  70  on the rod, thereby forming and completing the self-supported baffle assembly. 
     Next, the preassembled unit of baffles  50 ,  70  is slideably inserted into the internal passageway  25  of the outer sleeve  41  through open front or distal end  102  of the sleeve. The baffle unit is oriented so that the mounting rod  44  is slid into the tubular lower longitudinal chamber  48  of the sleeve  41 . Baffles  50 ,  70  are inserted such that the cones  72  face rearwards in the sleeve  41  (see, e.g.  FIGS. 4A-B ). The threaded rear end  121  of the mounting rod  44  is engaged with the threaded socket  118  of the barrel adapter  42  by rotating the rod using tooling socket  172  and a complementary shaped tool. This completes the integrally suppressed barrel assembly which appears as shown in  FIGS. 4A and 4B . The mounting rod  44  defines a mounting axis MA which is parallel and below the longitudinal axis LA of the barrel assembly  30  coinciding with the barrel bore centerline. 
     To remove the baffle assembly from the outer sleeve  41 , the mounting rod  44  is preferably rotated sufficiently to disengage the threaded rear end  121  from the threaded socket  118  of the barrel adapter  42 , but not threadably disengage threaded bottom aperture  56  of the spacer baffle  50 . This allows the entire stack of baffles  50 ,  70  to be removed from the sleeve  41  intact with the front end cap  43  as a unit (see, e.g.  FIG. 14 ). 
     It bears noting that in lieu of the foregoing preferred baffle mounting approaches in which the baffles are preassembled on the mounting rod  44  and then inserted into the sleeve  41  as a unit, other variations of the method are possible. For example, in other less preferred but still usable approaches the baffles may alternatively be inserted one at a time through the open front distal end  102  of the sleeve  41  to form the baffle stack therein. The mounting rod  44  with front end cap  43  positioned thereon may be slid through the lower mounting apertures  168  of the primary baffles  70  and threadably engaged with the threaded bottom aperture  56  of spacer baffle  50 , and then threaded socket  118  of the barrel adapter  42 . Tightening the mounting rod  44  will compress and draw the baffles  50 ,  70  together to create the interlocked press fit relationship desired for creating a gas tight barrier. 
     Any suitable materials may be used for the integrally suppressed barrel assembly and its components described herein. Preferably, the components are formed of an appropriate metal including alloys (with exception of any seals as needed) such as aluminum, carbon steel, stainless steel, titanium, or other. In one representative but non-limiting example, the rear and front end cap  27 ,  28  may be formed of aluminum or stainless steel. The barrel adapter  42  for example may be formed of carbon or stainless steel. The blast and primary baffles  50 ,  70  may be formed of stainless steel or aluminum as examples. The outer sleeve  21  may be formed of aluminum as an example. The sleeve  21  could also be made of preferably titanium due to its light weight and strength, or alternatively but less preferably of a steel material such as stainless due to its added weight. 
     While the foregoing description and drawings represent exemplary embodiments of the present disclosure, it will be understood that various additions, modifications and substitutions may be made therein without departing from the spirit and scope and range of equivalents of the accompanying claims. In particular, it will be clear to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, proportions, sizes, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. In addition, numerous variations in the methods/processes described herein may be made within the scope of the present disclosure. One skilled in the art will further appreciate that the embodiments may be used with many modifications of structure, arrangement, proportions, sizes, materials, and components and otherwise, used in the practice of the disclosure, which are particularly adapted to specific environments and operative requirements without departing from the principles described herein. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive. The appended claims should be construed broadly, to include other variants and embodiments of the disclosure, which may be made by those skilled in the art without departing from the scope and range of equivalents.