Patent Publication Number: US-2019195590-A1

Title: Firearm sound suppressor

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to sound suppressors and silencers for firearms, and more particularly to a suppressor having a modular system of baffles, a blast tube and an expansion tube removably and detachably joined with one another to facilitate customization and repair of components of the suppressor. 
     Firearm suppressors, also known as silencers, reduce the audible noise or sharp report of a firearm by controlling and reducing the energy levels of propellant gases discharged from the muzzle of the firearm. Most conventional suppressors include a tube or “can” having a series of baffles therein that control and delay the flow, expansion, and exit of propellant gases from the silencer. In so doing, the silencers achieve a corresponding reduction in the noise produced by the exiting propellant gases. 
     Many conventional suppressors include baffles and internal components that are fixedly welded to the silencer can and/or one another. Over time, the baffles and components can become dirty from the gases and debris carried in them. Because the components are fixed, they can be difficult to clean. Further, if a silencer is misaligned with a muzzle, a bullet can damage one of the baffles or other internal components. Due to the fixed connections, it can be difficult if not impossible to replace the damaged component and repair the suppressor. 
     Some suppressors include cans that are welded or joined with threads to end caps or other tubes. Where welded, the cans can be difficult to replace or change out when damaged due to a misaligned bullet or external impacts to the can. Where solely threaded together, the threads sometimes might not offer a perfect seal to prevent propellant gases from escaping therethrough. This can result in the discharge of hot propellant gases and associated debris where the components are joined. 
     In operation, as mentioned above, most silencers include baffles inside the can that control the flow, expansion and exit of propellant gases from the silencer. These baffles generally direct the flow of gases from the muzzle along a single pathway toward the exit of the can. Along the way, the baffles can dissipate and redirect the gases, but generally the single gas pathway leads through bullet apertures defined at an interior of the baffles or center of the can. While effective in many cases, the single gas pathway might present issues in effectively dissipating the gases and controlling expansion. 
     Some silencers are outfitted with an over the barrel expansion chamber which is basically an extension of the can that extends rearward of the muzzle, over a portion of the barrel to which the silencer is joined. While this can offer more area within the can to control and dissipate expanding gases, it can present issues when a user utilizes the silencer with different weapons. For example, the silencer and in particular the over the barrel expansion chamber may readily fit over a standard government profile barrel, however, when the user tries to put the silencer on a firearm with a bull barrel or odd front handguard, the over the barrel expansion chamber might not fit. This can limit the versatility of the silencer and its compatibility with different weapon systems. 
     Accordingly, there remains room for improvement in the field of silencers and suppressors for firearms. 
     SUMMARY OF THE INVENTION 
     A suppressor for reducing muzzle blast and noise of firearms is provided. 
     In one embodiment, the suppressor can include a baffle tube including a stack of baffle modules that are removably coupled to one another, independently supported from both bullet entry and exit ends of the tube, with the stack under tension and the tube under compression. With this support, the baffle modules can be adequately supported and aligned properly with one another and the baffle tube. 
     In another embodiment, the baffle stack can include a blast baffle that separates pressurized gas into a first pathway through the baffle stack and a second pathway between the exteriors of the baffle modules and the inside wall or surface of the baffle tube. Optionally, the second pathway can be a helical pathway defined between an interior surface of the blast tube and an exterior of the blast module. In some cases the helical pathway can be defined along the exterior of a module and/or an interior surface of the baffle tube. The second pathway can be distal from the first gas pathway, with the pathways can be separated by walls or portions of the baffle modules. Thus, the expanding propellant gas can be dissipated along different routes through the tube. 
     In still another embodiment, the suppressor can include two or more tubes joined with one another at ends having corresponding tapered flanges, optionally to seal and center the tubes relative to one another. For example, the baffle tube can include a first tapered sealing flange. The expansion chamber tube can include a second tapered sealing flange, with each including surfaces that correspond to and/or mirror one another. When the flanges are engaged under a compressive force pushing the surfaces into engagement with one another, optionally via a compression nut, the flanges produce a sealed joint between the tubes. Due to the taper of the surface, the tubes also achieve concentricity with one another so the interior surfaces and exterior surfaces of each of the tubes can be flush and/or aligned with one another. 
     In even another embodiment, the expansion tube can include a front rim and a rear rim. Each rim can include a tapered flange. The front rim can be sealingly engaged with the blast tube, and the rear rim can be sealingly engaged with a rearward end cap. 
     In a further embodiment, a forward tapered sealing flange of the expansion tube can seal with a rearward tapered sealing flange of the blast tube. These two components can be forced together with a compression nut threaded onto an exterior of the blast tube and/or expansion tube. 
     In still a further embodiment, the rearward tapered sealing flange of the expansion tube seals with a corresponding tapered sealing flange of the rearward end cap, and the two can be forced together via tightening a threaded portion of the rearward end cap onto a corresponding threaded portion of a muzzle interface of the expansion tube. 
     In yet another embodiment, the baffle tube and/or an expansion chamber tube can include a rearward end cap that is removable and replaceable with an over the barrel expansion tube. The over the barrel tube can include an inner tube and an outer tube. The inner tube can include a tapered flange that engages and seals against the rearward rim of the expansion tube after the rearward end cap is removed and replaced with the over the barrel expansion tube. The inner tube can include a threaded portion that engages threads of the muzzle interface. The flanges of the outer tube and expansion tube rearward rim can be forced together by tightening the inner tube. The resultant joint is sealed to prevent expanding, pressurized gases from escaping. 
     These and other objects, advantages, and features of the invention will be more fully understood and appreciated by reference to the description of the current embodiment and the drawings. 
     Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited to the details of operation or to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention may be implemented in various other embodiments and of being practiced or being carried out in alternative ways not expressly disclosed herein. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, enumeration may be used in the description of various embodiments. Unless otherwise expressly stated, the use of enumeration should not be construed as limiting the invention to any specific order or number of components. Nor should the use of enumeration be construed as excluding from the scope of the invention any additional steps or components that might be combined with or into the enumerated steps or components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the suppressor of a current embodiment; 
         FIG. 2  is a right side view of the suppressor, the left side view being a mirror image thereof; 
         FIG. 3  is a section view of the suppressor taken along lines  3 - 3  of  FIG. 2 ; 
         FIG. 4  is a front view of the suppressor; 
         FIG. 5  is a rear view of the suppressor; 
         FIG. 6  is an exploded view of an expansion chamber tube and a baffle tube of the suppressor, along with a compression nut and rearward end cap; 
         FIG. 7  is an exploded view of a blast baffle, baffle modules, an end cap and an end cap insert of the suppressor; 
         FIG. 8  is a perspective view of the blast baffle; 
         FIG. 9  is a bullet entry side, rear view of the blast baffle; 
         FIG. 10  is a right side view of the suppressor including an over the barrel expansion chamber, the left side view being a mirror image thereof; 
         FIG. 11  is a section view of the suppressor taken along line  11 - 11  of  FIG. 10 ; and 
         FIG. 12  is a rear exploded view of the over the barrel expansion chamber relative to the expansion chamber and baffle tube of the suppressor. 
     
    
    
     DESCRIPTION OF THE CURRENT EMBODIMENTS 
     A current embodiment of the suppressor is illustrated in  FIGS. 1-12 , and generally designated  10 . The suppressor  10 , also referred to as a silencer herein, can include an elongate baffle tube  20  that can house a front end cap insert  30  and a front end cap  40 , along with one or more baffle modules  50 ,  60  and a blast baffle  70 . The baffle tube  20  can be joined with an expansion chamber tube  80  configured to lower the pressure and temperature of the discharged propellant gases, from the firearm muzzle or muzzle break to which it is attached, to a level beneficial to the function of the components in the remaining paths through the silencer. As described later in connection with  FIGS. 10-12 , the suppressor  10  can include an optional over the barrel expansion tube or chamber  90 , which is by its namesake, configured to extend rearward over a portion of the barrel B of the firearm to which the suppressor  10  is joined. This over the barrel expansion tube  90 , however, can be removable from the expansion chamber  80  and replaceable with a rearward end cap  86 , so the suppressor can be selectively used with or without the over the barrel tube  90 . 
     Generally, the foregoing components of the suppressor  10  reduce the energy of propellant gases, thus achieving a corresponding reduction of associated firing noise and signature. The internal components of the suppressor contain, delay, deflect, control, and/or disperse gases associated with a bullet exiting the barrel B of the firearm. 
     The components of the suppressor  10  can be manufactured from a variety of materials, alone or in combination, including but not limited to titanium, aluminum, steel, alloys, resins, polymers, composites, carbon fiber, heat dissipating materials, carbon fiber reinforced ceramics or other heat-conducting, heat-resistant material, and any like materials. Notably, the projectile referred to herein is frequently described as a “bullet” for illustrative purposes, but any suitable projectile may be used in connection with the suppressor. Further, the suppressor can be joined with any suitable firearm, or other projectile shooting device, regardless of whether it technically is considered a firearm. Any such firearm or projectile shooting device is generally referred to herein as a “firearm.” 
     Turning now to  FIGS. 1-6 , the suppressor and its components will now be described in more detail. To begin the suppressor includes the elongate baffle tube  20 . This baffle tube  20  includes a bullet entry end  21 , an opposing bullet exit end  22  and a longitudinal axis LA. The baffle tube can delineate or house a bullet pathway BP extending longitudinally therethrough from the bullet entry end to the bullet exit end. This bullet pathway BP can be aligned with and can follow the longitudinal axis LA. Optionally, the respective bullet entry end  21  and opposing bullet exit end  22  can be joined with respective other components of the suppressor  10 . 
     Further optionally, the bullet openings at the respective ends need not be perfectly sized to accommodate a particular caliber bullet. Instead, the forward or front end cap and/or forward end cap insert, rearward end cap and/or expansion chamber tube can be sized to have bullet passageways or openings that correspond to one or more calibers for which the suppressor is designed. More particularly, the front end cap insert  30  and/or front end cap  40 , as well as the rear of the expansion chamber tube  80  can define respective bullet openings  30 O,  40 O and  80 O sized for a particular caliber bullet which for which the suppressor is designed. Of course, as described further below, the expansion chamber tube  80  can include an over the muzzle interface  83  which joins to a muzzle break or muzzle of a firearm. 
     The baffle tube  20  can further include a sidewall  20 S having an interior and an exterior, so that the blast baffle tube forms a tubular casing or enclosure. As used herein, the term “tubular” refers to an elongate structure with an outer sidewall  20 S and a hollow interior  20 I, wherein the cross-sectional shape of the structure may be any closed shaped, such as a curved shape, for example, a circle, ellipse, oval, or the like, or a polygonal shape, for example, a triangle, rectangle, square, pentagon, hexagon or the like. 
     The elongate baffle tube  20  can be constructed to include a front or forward rim  20 FR disposed at the forward portion of the sidewall  20 S. This front rim  20 FR optionally can circumscribe and/or surround all or part of the opening defined at the bullet exit end  22  of the suppressor. The forward rim  20 FR can be of the same thickness as the sidewall  20 S. Rearward of the forward rim  20 FR, however, the sidewall  20 S can define front threads  20 FT. These threads can be configured to threadably couple components of the baffle stack SOBS, having corresponding threads, to the elongate baffle tube  20  as described in further detail below. Generally, the threads can circumscribe and/or surround all or part of the opening defined at the bullet exit end  22  of the suppressor and/or all or part of the forward end cap  40  and insert  30 . 
     The baffle tube  20  can include a rear rim  20 RR distal from the front rim  20 FR and generally disposed adjacent the bullet entry opening  21 . The sidewall  20 S can extend between the forward rim and the rearward rim. The rear rim  20 RR can circumscribe and/or surround all or part of the opening defined at the bullet entry end  21  of the baffle tube  20 . The rear rim  20 RR can include and/or be formed as a support rim  23 . This support rim  23  can be configured to support and/or engage the blast baffle  70  and/or a portion of the expansion chamber tube  80 . For example, the support rim  23  can include a lip  23 L that can be disposed around the opening of the bullet entry end of the baffle tube  20 . This lip can engage a ring of the blast baffle  70  as described further below. 
     The bullet entry end  21  of the baffle tube  20  also can include an elongate baffle tube tapered flange  24  adjacent and/or forming part of the support rim  23 . This tapered flange can be a frustoconical shaped flange that flares outwardly when extending toward the bullet exit end  22  of the baffle tube  20 . More particularly, the flange can flare out at an angle relative to the sidewall  20 S of the tube  20 . Alternatively, the flange can flare out in a curved manner relative to the sidewall  20 S of the tube  20 . The flange can be annular and can circumscribe all or part of the opening of the bullet entry end  21  of the tube  20 . 
     Optionally, the tapered flange  24  can be structured and shaped so that it can engage a corresponding tapered flange  84  of the expansion chamber tube  80 , and optionally form a sealing engagement between the baffle tube  20  and the expansion chamber tube  80  at the corresponding joint. By sealing engagement it is meant that the flanges surfaces engage one another and substantially prevent propellant gases from being discharged at the join points of engagement around the respective flanges. The expansion chamber tapered flange  84  can be flared inward toward an interior  80 I of the expansion chamber tube  80 . Optionally, the expansion chamber tapered flange  84  can form a frustoconical recess or region around the forward rim  80 FR of the expansion chamber tube  80 . This frustoconical recess can receive a like shaped frustoconical tapered flange  24  of the elongate baffle tube  20 , allowing the flanges to seat in sealing engagement against one another. Given the interface of these flanges  24  and  84  and their shapes, the baffle tube  20  can be forced into concentricity and alignment with the expansion chamber tube  80 , in which case, the interior and exterior surfaces of these tubes can be aligned and parallel with, but in some cases, slightly offset from one another. 
     Optionally, the blast tube  20  and expansion tube  80  can be secured to one another with a compression nut  25 , also referred to as a jam nut herein. The jam nut can include a threaded portion  25 T that threadably couples the compression nut  25  to the corresponding expansion chamber tube  80 , optionally via corresponding threads  85 T associated with an exterior of the expansion chamber tube  80 . When the compression nut  25  is tightened, an internal shoulder  25 S of the nut engages the tapered flange  24  along a ledge  24 L. Upon engagement of the shoulder  25 S with the ledge  24 L, and subsequent tightening of the compression nut, the expansion chamber tube  80  is drawn toward the elongate baffle tube  20 . This in turn forces the tapered flanges  24 ,  84  against one another so that they effectively form one or more sealed surfaces around the joined ends of the tubes. This in turn can form a sealed joint at their interface, which can contain the gases inside the expansion tube and blast tube. Due to the taper, this force exerted by the compression nut also forces the above-mentioned concentricity and general alignment of the two tubes relative to one another. Optionally, the configurations of the flanges  24  and  84  can be reversed, so that these are on the opposite structures than as shown. Further optionally, the location of the threads can be modified, for example, the threads can be included on the baffle tube  20  so that the compression nut  25  can be oriented in a reverse manner to secure the expansion tube  80  to the elongate baffle tube  20 . Even further optionally, the tapered flanges used to seal the tubes at a joint can be replaced with other structures. For example, the flanges can be substituted with gaskets, high temperature o-rings and respective grooves in the respective rims to hold the gaskets and/or o-rings. 
     As illustrated, the expansion chamber tube  80  can be joined with but removable from the elongate baffle tube  20  with the use of tools and/or manually, and without the destruction of either of the tubes. In this manner, the different components, in particular the tubes can be replaced and/or repaired relative to one another. Alternatively, the expansion chamber tube  80  can be integrally formed as a single piece unit with the elongate baffle tube  20 , in which case it may still be considered to be joined with the baffle tube  20 . 
     Referring now to  FIGS. 3 and 4 , the expansion tube  80 , as explained above, is secured to the baffle tube  20 . The expansion tube  80  can define an internal chamber  80 I. It is this internal chamber that forms the expansion chamber of the suppressor for receiving pressurized propellant gases as they are expelled from a barrel to which the suppressor is attached. This large internal chamber helps dissipate the gases and reduce temperatures of the suppressor caused by the expulsion of those gases therein. While a blast baffle or baffle modules can be disposed in the baffle tube, optionally no blast baffle or baffle module is disposed in the expansion chamber tube  80 , in which case the expansion tube includes no part of the baffle stack SOBS. Further, the internal cavity  80 I optionally can be void of any internal components between the muzzle interface  83  and the tapered flange  84  or lip. 
     The expansion chamber tube  80  can extend from the front rim  80 FR to the rear rim  80 RR, with a sidewall  80 S extending therebetween. This sidewall can include one or more annular protrusions on the exterior  80 E of the tube. One protrusion  80 P can form a seat against which the compression nut  25  can be tightened when securing the expansion chamber tube to the elongate baffle tube  20 . 
     As shown in  FIG. 3 , the expansion chamber tube  80  can be joined with a muzzle interface  83 . This muzzle interface can include threads  83 T configured to threadably engage and join with threads on a firearm barrel or a muzzle break joined with the barrel, depending on the application. In turn, this can secure the expansion tube and thus the remainder of the suppressor  10  to the firearm, in particular the muzzle of the barrel. The muzzle interface  83  can project rearwardly beyond the rear rim  80 RR of the expansion chamber tube. The interface  83  can include a central portion  83 C to which one or more webs  83 W are secured. These webs can define one or more backflow ports  83 P through which propellant gases can be dissipated rearward and over at least a portion of the central portion  83 C of the interface  83 . Optionally, when dissipated rearward, the gases can engage and enter an internal annular cavity  86 I of the rearward end cap  86 , or when the over the barrel expansion chamber  90  is replaced for the end cap  86 , the gases can enter and engage the internal cavity  90 I thereof. 
     As illustrated in  FIG. 3 , the suppressor  10  is set up with a rearward end cap  86 . This rearward end cap  86  is joined with the expansion chamber tube  80 . In particular, the rearward end  86  can include threads  86 T that threadably engage exterior threads  83 ET on the exterior of the central portion  83 C of the muzzle interface  83 . The rearward end cap  86  also can include a forward flange  86 SF that is configured to engage the rearward rim  80 RR of the expansion chamber tube  80 . In particular, this flange  86 SF can be tapered, similar to the taper of the flange  84  at the front of the expansion chamber tube  80 . Generally, the flange  86 SF can form a frustoconical annular ring or recess about an outer perimeter or circumference of the rearward end cap  86 . The rear rim  80 RR can include a taper  80 RRT as well. This taper  80 RRT can correspond to the taper of the flange  86 SF. When the rearward end cap  86  is tightened onto the central portion  83 C of the interface  83 , the tapered flange  86 SF of the rearward end cap  86  engages the rearward rim  80 RR and taper  80 RRT of the expansion chamber tube  80 . Accordingly, these two components can be brought into sealing engagement with one another and forcibly engaged against one another. The sealing also forces concentricity of the rearward end cap  86  relative to the expansion tube  80 . Optionally, the rearward end cap  86  can be manufactured to mate directly to the barrel and/or muzzle of the firearm, instead of the interface  83 , and can incorporate an attachment mechanism that facilitates rapid attachment or detachment of the expansion tube  80  and/or blast tube  20 . 
     Suppressor  10 , as shown in  FIGS. 2-7  can include a baffle stack  50 BS. This baffle stack  50 BS can be disposed substantially entirely in the baffle tube  20 . Of course in some cases, where the expansion chamber tube is integral with the elongate tube  20 , the baffle stack and its components can extend into the expansion chamber tube as well. Generally speaking, the baffle stack can include at least two baffle modules  51 ,  52 ,  60 , and a blast baffle  70 . The baffle stack SOBS also can include a forward end cap  40  and a forward end cap insert  30 . Each of these elements will now be described in detail. 
     To begin, the forward end cap insert  30  can include a base portion  31 . The base portion  31  can include and define a bullet passageway or opening  30 O generally centered on the longitudinal axis and/or bullet pathway LA, BP. The base can include external threads  31 T. These threads can threadably engage internal threads  41 IT of the forward end cap  40 , thereby enabling these two components to be joined with one another. The forward end cap insert  30  optionally can be seated on the front rim  20 FR of the tube  20 . As shown, the end cap insert  30  includes an annular ring  30 R that seats against a shoulder  40 S of the forward end cap  40 . The seating is achieved when the forward end cap insert  30  is sufficiently tightened into the forward end cap  40 . 
     The forward end cap insert  30  can be disposed at the bullet exit end  22  of the blast tube  20 , and optionally can be the last element through which the bullet travels as it leaves the suppressor  10 . The forward end cap insert  30  can include a first portion  43  that extends rearward from the base  31 . In particular, the base can include a rearward wall  33 RW. The first portion  43  can extend rearward from this wall. The first portion  33  can define a forward end cap insert first portion bore  33 B. This bore can be in spatial communication with the opening  30 O extending through the forward end cap insert. The first portion optionally can be cylindrical in shape, as can be the base  31 . Optionally, the base can be of a larger diameter than the diameter of the first portion when in a cylindrical shape. Of course, where different shapes are utilized for these components, the dimensions can vary accordingly. 
     The forward end cap insert  30  can include a bullet entry opening  30 EO. This is the opening through which the bullet initially traverses into the first portion  43 . In this region, adjacent the bullet entry opening  30 EO of the end cap insert, the first portion  43  can include a blast diffusion flange  30 R, which can include a plurality of optional cast, molded, raised, or machined steps or ridges. These steps or ridges can add surface area and/or direct, focus, diffuse, and/or impede propellant gas flow as it approaches the bullet entry opening  30 EO. Generally, the diffusion flange  30 R can diffuse gases outward away from the longitudinal axis LA and into a front end baffle expansion chamber  40 EC as described in further detail below. After the gases pass the widest portion of the ridges or steps of the diffusion flange, they become at least partially trapped between the base  31 , its rearward wall  33 RW, the flange  30 R and the interior of the portion  43  to dissipate energy of those gases. 
     Optionally, as shown in  FIG. 7 , the forward end cap insert  30  can be constructed so that the base  31  includes a first diameter D 1  and the first portion  33  includes a second diameter D 2 , while the flange and its optional ridges and/or steps are constructed to include a third diameter D 3 . The first diameter D 1  can be greater than the second diameter D 2  and the third diameter D 3 . The diameter D 2  of the first portion  33  can be less than the diameter D 3  of the diffusion flange  30 R. In some applications, the respective bores inside the first portion and base can have correspondingly sized dimensions. Further optionally, in some cases, the flange  30 R can be eliminated from the construction, with the first portion being a cylindrical element terminating adjacent the entry opening  30 EO. Alternatively, other types of projections, protuberances, scallops, bumps or the like can be disposed on the first portion to diffuse gas like the diffusion flange. 
     The forward end cap insert  30 , as mentioned above can be threadably coupled to the forward end cap  40 . This is so that these two components can be separated from one another with tools or manually, without destroying either of the components. The forward end  40  can include a base  41 . This base can include internal threads  41 IT that mate with the forward end cap insert threads  31 T to secure these components to one another. The base  41  also can include external threads  41 ET. These threads can threadably engage and correspond to the threads  20 FT of the baffle tube  20 , thereby securing the forward end cap  40  to the baffle tube  20 , optionally with the tube under compression and the cap and other baffle stack SOBS components under tension, respectively as described below. The base  41  can include a shoulder  41 S that is configured to engage against the front rim  20 FR of the tube  20  when the forward end cap  40  is sufficiently tightened relative to the other components of the baffle stack SOBS. 
     The forward end cap  40  can include a second portion  43  extending from the base  41 . The second portion  43  can join the base at a shoulder  43 S, such that the base  41  is slightly larger than the second portion  43 , when measured at the external and internal surfaces thereof. The second portion  43  can include a second portion bore  43 B. This second portion  43  can be cylindrical, as can be the base  41 . The second portion  43  can include a rearward wall  43 RW that transitions to a first portion  44  when extending rearwardly toward the bullet entry end  21  of the elongate tube  20 . The first portion  44  can include a first portion bore  44 B. This first portion bore  44 B can transition to a bullet entry opening  40 EO. The second portion bore  43 B can be of a diameter D 4  that is greater than the diameter D 3  of the diffusion flange  30 R noted above. This is so that the flange  30 R of the forward end cap insert  30  can fit within and be disposed within the second portion bore  43 B, with the flange  30 R spaced inwardly from the second portion  43  to allow gases to diffuse beyond the flange  30 R. 
     Optionally, the base  41 , second portion  43 , first portion  44  and flange  40 R, when of a cylindrical shape, can be of varying diameters. For example, the base  41  can be of a first diameter D 4 , the second portion  43  can be of a second diameter D 5 , the first portion  44  can be of a diameter D 6  and the flange  40 R can be of a maximum flange diameter D 7 . The diameter D 7  can be larger than the diameter D 6 , yet smaller than the diameters D 5  and/or D 4  where included. 
     Referring to  FIGS. 3 and 7 , the baffle stack SOBS, as mentioned above, also can include one or more baffle modules  50 ,  60 . These baffle modules can be slightly different from one another. For example, the baffle modules  50 , in particular the first baffle module  51  and the second baffle module  52 , as shown in  FIG. 7 , can be substantially identical. Optionally, the baffle modules  51 ,  52  can be duplicated in number depending on the particular application. For example, in some applications additional noise suppression may be desired. In this case, the baffle tube  20  can be lengthened and additional baffle modules  50  can be secured to the illustrated baffle modules  51  and  52 . In some cases one, two, three, four, five or more additional baffle modules can be utilized depending on the application. In other applications, where less noise suppression is acceptable, one of the baffle modules  51  or  52  can be eliminated. 
     The baffle modules  51 ,  52  can be substantially identical, so only the first baffle module  51  will be described here. In particular, the first baffle module  51  is sized so that its exterior dimensions enable the first baffle module  51  to be disposed inside the elongate tube  20  between the bullet entry end  21  and the bullet exit end  22 . The first baffle module  51  can include an exterior  51 E and an interior  51 I. The exterior  51 E can include a threaded exterior connector interface  51 EC. The interior can include a threaded interior connector interface  51 IC. The threaded interior connector interface  51 IC can be configured to engage the threads  43 T on the exterior of the forward end cap  40  to threadably join the first baffle module  51  to that end cap  40 . The threaded exterior connector interface  51 EC can be configured to engage the threads  52 IC of the next adjacent or second baffle module  52  to secure those components together. 
     The baffle module  51  can define a baffle module bullet opening  51 O aligned with the bullet pathway, as well as a bullet entry opening  51 EO through which the bullet initially enters the baffle module. The first baffle module  51  can include a first baffle module portion  55  that defines a first baffle module bore  55 B. This first portion  55  can transition to a second baffle module portion  56  that defines a second baffle module bore  56 B. Optionally, the first baffle module bore  55 B of a larger internal dimension than the second baffle module bore  56 B. Further optionally, the first portion  55  can include a rearward wall  55 RW. The second baffle portion  56  can extend from this wall and can be continuous therewith. 
     As shown in  FIGS. 3 and 7 , the second portion  56  can include a shoulder  56 S. The exterior connector interface  51 EC can be disposed adjacent and rearward of this shoulder  56 S. In some cases, the next or second baffle module  52  can bottom out against the shoulder  56 S upon sufficient tightening of the same. As mentioned above, the second portion  55  can be larger than the first portion  56 , particularly along the external surfaces thereof. The second portion  55  can include a second portion bore  55 B or chamber. This second portion bore  55 B can include one or more internal diameters, depending on the location relative to the shoulder  55 S. This second portion  55  can be cylindrical, as can be the first portion  56 . The second portion  55  can transition to the first portion  56  when extending rearwardly toward the bullet entry end  21  of the elongate tube  20 . For example, the second portion can include a rearward wall  56 RW from which the first portion  56  extends rearwardly. 
     The first portion  56  can include a first portion bore  56 B. This first portion bore  56 B can transition to a bullet entry opening  51 EO. A diffusion flange  40 R like that described above, can be disposed adjacent and/or surround the opening  51 EO. The second portion bore  55 B can be of a diameter D 8  that is greater than the diameter D 7  of the ridges or steps of the diffusion flange  40 R, which as illustrated, is in the form of a stepped cone. This is so that the diffusion flange  40 R of the forward end cap  40  can fit within and be disposed within the second portion bore  55 B. Thus, the flange  40 R can be spaced inward from the second portion  55  and its internal walls to allow gases to pass forward and beyond the flange  40 R. Alternatively, the end of the first portion adjacent the bullet entry opening  50 EO can be void of the stepped cone or ridged flange, simply terminating at a circular opening there. 
     Optionally, the second portion  55  forms the interior chamber  51 I associated with the second portion bore  55 B. In this region, forward of the flange  40 R of the forward end cap  40 , dissipating and expanding gases can expand and bounce off the walls thereof and the corresponding first portion  44  of the forward end cap  40  disposed in that bore. Again this can enhance the diffusion of gases, thereby reducing the energy levels of the propellant gases within this baffle module. 
     Further optionally, the second portion  55 , first portion  56  and flange  50 R can be of varying diameters. For example, the second portion  55  can be of a diameter D 10 , the first portion can be of an external diameter D 11  and the flange  50 R can be of a maximum diameter D 12 . The diameter D 12  can be larger than the diameter D 11  yet smaller than the diameter D 10 . 
     As shown in  FIGS. 3 and 7 , the baffle module  51  can be outfitted with an outer wall or surface  55 W. This outer wall or surface can define a plurality of grooves  55 G. These grooves  55 G can be helical in structure, or generally forming large threads that coil around the exterior of the first blast baffle  51 . When the baffle stack SOBS is placed inside the baffle tube  20 , these grooves and the respective threads  55 T therebetween are disposed immediately adjacent, and in some cases, contact or otherwise engage the interior surface of the sidewall  20 S. These grooves thereby provide a second gas pathway for the gases to travel and thereby reduce energy as described in further detail below. The sidewall  55 W also can define a region  55 F that is generally flat. This flat region  55 F can be disposed adjacent the grooves  55 G and threads  55 T, without those elements extending into the flat region  55 F, except in some alternative applications. In this manner, gases flowing along a second gas pathway GP 2  through the grooves, between the baffle module wall  55 W and the sidewall  20 S of the tube, can exit those grooves  55 G, can enter a void or space  55 V that is disposed between the interior surface of sidewall  20 S and the flat region  55 F of the first baffle module  51 . It also will be appreciated that the flat region  55 F can be flat as it extends along lines parallel to the longitudinal axis LA, but that because the baffle module  51  can be cylindrical, the region  55 F is rounded as it extends around the longitudinal axis. 
     The baffle stack SOBS can be configured so that multiple baffle modules, for example  51 ,  52  and  60  can be disposed in series and can extend from the bullet entry end  21  to the bullet exit end  22  of the baffle tube  20 . Between these ends, the baffle modules, for example  51 ,  52  and  60 , can include one or more sets of grooves, for example, like those helical grooves  55 G described above. These grooves, however, can be separated from one another by flat cylindrical portions, for example  55 F, of the respective modules so that a gas can travel along a second gas pathway GP 2 , through grooves of one baffle module, then through another void formed over a flat or cylindrical region of the module, then enter another set of grooves, then over yet another flat or cylindrical region of the next module, then enter yet another set of grooves, to expand over yet another flat region of the next module. In this manner, the second gas pathway GP 2  can basically be helical along a first portion, linear through a second portion, helical again through another portion, linear yet again through another portion, helical through another portion, then again linear along another portion of the respective baffle modules, and so on, depending on the number of baffle modules. Again the gases travel along these helical and linear paths, between the exterior surfaces and/or walls of the respective baffle modules and the interior surface of the sidewall  20 S of the baffle tube  20 . As described below, this second gas pathway GP 2  can be separate and distinct from a first gas pathway GP 1  that coincides with gases traveling through the respective bullet openings of the modules and other components, generally along the longitudinal axis LA and/or bullet path BP. 
     As mentioned above, the second baffle module  52  can be threadably joined with the first baffle module  51 . The other features of this second baffle module  52  can be substantially identical to that of the first baffle module  51  and therefore will not be repeated again here. Further, as mentioned above, multiple additional identical baffle modules can be added to the suppressor to enhance or change noise attenuation and intensity. 
     Referring to  FIGS. 3 and 7 , the suppressor  10  can include a different type of baffle module  60 , which can be slightly different from the modules  51  and  52  described above. For example, this baffle module  60  can include an exterior  61 E and an interior  61 I. The exterior  61 E can include a threaded exterior connector interface  61 EC and the interior can include a threaded interior connector interface  61 IC. The threaded interior connector interface  61 IC can be configured to engage the threads on the exterior of the second baffle  52  exterior connector interface  52 EC, thereby threadably joining the third baffle module  60  to that second baffle module  52 . The threaded exterior connector interface  61 EC can be configured to engage the threads  71 IC of the next adjacent baffle module or a blast baffle  70  as shown. 
     The baffle module  60  can define a baffle module bullet opening  61 O aligned with the bullet pathway, as well as a bullet entry opening  61 EO. The baffle module  60  can include a first baffle module portion  65  that defines a first baffle module bore  65 B. This first portion  65  can transition to a second baffle module portion  66  that defines a second baffle module bore  66 B. Optionally, the first baffle module bore  65 B is of a larger internal dimension than the second baffle module bore  66 B. Further optionally the second baffle module bore  66 B can be larger than the bores  56 B and  44 B of the other baffle modules and forward end cap insert. 
     As shown in  FIGS. 3 and 7 , the second portion  66  can include a shoulder  66 S. As mentioned above, the exterior connector interface  61 EC can be disposed adjacent this shoulder  66 S. In some cases, the next or baffle module or blast baffle  70  as shown can bottom out against the shoulder or the adjacent rearward wall  66 RW upon sufficient tightening of the same. 
     The baffle module  60  optionally can be constructed so that it does not include any type of diffusion flange around the bullet entry opening  61 EO. This is so that the baffle module  60  can interface well with the blast baffle  70  as described in further detail below. 
     The baffle module can include a ramped surface  67  adjacent the shoulder  66 S and/or the rearward wall  66 RW. This ramped surface  67  can lead into or transition to the helical grooves  65 G defined by the exterior  60  of the baffle module  60 . This ramped surface  67 , which can be annular, also can abut and be adjacent the external surface  71 G and the second portion  72  of the blast baffle  70 . Thus, when the blast tube  20  is disposed over these elements, the second gas pathway GP 2  is established between the exterior  71 E of the blast baffle  70  and the interior of the blast tube sidewall  20 S. That second gas pathway GP 2  leads directly to the ramped surface  67  which directs the gas into the helical grooves  65 G of the blast module  60 . From there, the gas pathway proceeds over the respective flat exterior regions of the baffle module  60  and into subsequent helical and flat regions of additional baffle modules, all while traveling along the second gas pathway GP 2 , all while between the exterior surfaces of the blast baffle and baffle modules, generally between the baffle modules and the interior surface of the sidewall  20 S of the baffle tube  20 . 
     The baffle stack SOBS, as mentioned above, also can include a blast baffle  70 . This blast baffle  70 , shown in  FIGS. 3 and 7-9 , can be joined with the next adjacent baffle module, which can be a baffle module like that of the baffle module  60 , or some modification of the baffle modules  51  and  52 . Generally, the blast baffle  70  defines a blast baffle bullet opening  70 O, as well as a bullet entry opening  70 EO at the rearward portion of the blast baffle  70 . The blast baffle bullet opening  70 O and bullet entry opening  70 EO can be generally aligned with and concentric with the bullet pathway BP and/or the longitudinal axis LA. 
     The blast baffle  70  can include a base  71  that transitions to an inner core  72 . The inner core can be joined with a support ring  73  having a support seat  73 S. The inner core can be joined with the support ring via one or more webs  73 W. The base  71  optionally can be of a cylindrical shape and can include an interior connector interface  71 IC, which can be threaded. In this manner, the blast baffle can be threadably joined with the exterior connector interface  61 EC of the next adjacent baffle module  60 . The base can include an exterior  71 E that is substantially featureless, and can form a flat region that aligns in parallel to the bullet path or longitudinal axis. The base  71  can transition to the inner core  72  along a ramped or angled portion  71 A, which also can be referred to as a transition portion or region. This ramped portion  71 A can flare outward, away from the bullet pathway or longitudinal axis as it extends forward the bullet exit end  22  of the suppressor  10 . Although shown as a frustoconical shape, the surface can include one or more grooves, recesses, scallops, or pathways that facilitate and/or impair travel of gas along a second gas pathway GP 2 , which extends generally through the secondary ports  73 P, beyond the webs  73 W, past the inner core  72 , up and over the ramp portion  71 A, over the exterior  71 E, over the ramped surface  67  and into the helical grooves  65 G defined between the respective baffle modules and the interior surface of the sidewall  20 S of the elongate baffle tube  20 . 
     The blast baffle, as mentioned above and shown in  FIGS. 8 and 9 , can include an inner core  72  that is joined with and optionally integral with the ramped portion  71 A. The inner core can be suspended from the ring by one or more webs and extends forward from the ring toward the bullet exit end of the baffle tube. This inner core  72  defines the bullet opening  70 O and an adjacent internal bore  70 B. This internal bore  70 B can be of a lesser dimension than the internal bore  71 B of the base  71 , which itself can be considered an extension or a portion of the inner core. Optionally, the inner core  72  can be considered to include a first portion that defines a first blast baffle bore  70 B. The first portion  72  can transition at a transition region, which can coincide with the ramped portion  71 A, to the second portion, which can coincide with the base  71 , that defines a second blast baffle bore  71 B. Depending on the application, the second blast baffle bore can be of larger internal and external dimension/diameter than the first blast baffle bore. 
     At the rearward portion of the inner core  72 , the area adjacent the opening  70 EO can include a rearward surface  72 R that is configured to direct gases along the second gas pathway GP 2 , up over the exterior of the inner core  72  and so on. The rearward surface can include a ramped, tapered and/or curved contour to split gases off from the first gas pathway GP 1 . The inner core can be joined with one or more webs  73 W that extend radially outwardly from the longitudinal axis LA. These webs can be connected at their outermost edges or parts with the support ring  73 . Between the support webs  73 W and optionally between the inner core and ring, one or more secondary ports  73 P are defined. The secondary ports can be offset radially from the bullet opening  70 O and the bullet entry opening  70 EO of the blast baffle  70 . It is through the secondary ports  73 P that the propellant gas, as described below, enters and travels along the second gas pathway GP 2 . However, it is through the opening  70 O, and in particular the bullet entry opening  70 EO of the inner core, where the gases from the expansion chamber tube  80  enter the interior of the blast baffle to travel along the first gas pathway GP 1  to be expelled into the subsequent baffle modules in the baffle stack SOBS. 
     Although shown as including three support webs  73 W in  FIG. 8 , any number of webs can be used in this blast baffle  70  to support the ring. The support ring, as mentioned above, can include a support seat  73 S. This seat  73 S can be the side of the ring or flange that faces toward the forward or bullet exit end  22  of the baffle tube  20 . The seat can include a tapered, curved and/or ramped surface. The seat  73 S can be configured to directly engage the support rim  23 , and in particular, the lip  23 L thereof. In this manner, the blast baffle can be seated, via the support ring engaged with the support rim  23 . Optionally, the seat  73 S can be annually disposed around the entire ring. 
     As shown in  FIG. 3 , the seat  73 S and lip  23 L can be of mirror shapes so that one fits within and/or nests directly in the other in a sealing manner. Indeed, these shapes can assist in concentrically aligning the bullet path BP and longitudinal axis LA centrally within the baffle tube  20 . These features, as well as those at the bullet exit end  22  also can assist in supporting the components of the baffle stack SOBS in concentricity with the tube and one another. For example, when the entire baffle stack SOBS is assembled in the baffle tube  20 , with the respective forward end cap  40 , baffle modules  51 ,  52  and  60 , and blast baffle  70  being disposed in the interior  20 I of the tube, the entire stack SOBS and its components can be supported from both the bullet entry end  21  and from the bullet exit end  22 . In particular, after blast baffle and designated number of baffle modules and end cap are threadably coupled and tightened relative to one another, the forward end cap  40  and/or an forward end cap insert  30  can be tightened. This tightening draws the baffle stack SOBS generally toward the bullet exit opening  22  of the tube  20 . In turn, this pulls the seat  73 S against the support rim  23 , in particular, the lip  23 L. As the forward end cap  40  is further tightened relative to the bullet exit end  22  of the baffle tube  20 , a compression force CF is borne by or exerted on the elongate baffle tube  20 , while a corresponding tension force TF is borne by or exerted on the forward end cap, baffle modules and the blast baffle so as to further forcibly and sealingly engage the support seat of the blast baffle against the support rim of the baffle tube. In turn, the end cap, baffle modules and the blast baffle are supported at both the bullet entry end and the bullet exit end of the elongate baffle tube. This provides a secure mounting of these structures, and can ensure proper alignment of the respective bullet openings of each of the components with the bullet pathway BP, which in turn can reduce the likelihood of a bullet misaligned with the openings, which can potentially collide with the components and damage them. 
     The different and distinct gas pathways provided by the suppressor  10  of the current embodiment now will be described in further detail. To begin, it will be understood that upon firing the firearm to which the suppressor  10  is joined, a bullet exits the muzzle of the firearm, and thus enters the suppressor at speeds typically above 900 feet per second (fps) and generally lower than 4000 fps. The propellant gases that push the bullet, however, are expanding and can achieve much higher speeds. These propellant gases, which are rapidly expanding, are managed by the suppressor  10 . In particular, the blast baffle  70  and suppressor  10  of the current embodiment, dissipate the expanding propellant gases, redirecting them to travel along two distinct gas pathways. For example, referring to  FIGS. 3 and 7-9 , the blast baffle  70  can separate propellant gases expanding from and diffusing from the expansion chamber tube  80  into a first gas pathway GP 1  and a second gas pathway GP 2 . In particular, when the propellant gases under pressure, exit the expansion chamber tube  80  and enter the blast baffle  70 , a significant portion of these propellant gases are expelled along the bullet pathway BP and generally along the longitudinal axis LA. These gases generally impinge the blast baffle and are diffused by the blast baffle into the first gas pathway GP 1  coinciding with the bullet pathway BP. This first gas pathway extends and projects into the entry opening  70 EO and opening  70 O of the blast baffle  70 . The gases then traverse into the inner core, inside the bore  70 B and expand outward into the next adjacent bore  71 B within the blast baffle  70 . A portion of those gases along that first gas pathway continue along the bullet pathway and enter the opening  61 EO of the next baffle module  60 . Those gases then continue along the bullet pathway BP and enter the bullet entry openings, for example  50 EO,  40 EO and  30 EO of subsequent baffle modules and end caps and end inserts. 
     Generally, the blast baffle inner core bore  70 B and the inner core bullet entry opening  70 EO are in fluid communication with a first gas pathway GP 1 . When gas traveling and expanding along the first gas pathway GP 1  enters the baffle module  60 , because the flange  52 R of the next adjacent baffle module  52  surrounds the bullet entry opening  52 EO of that baffle module, some of the gases are dissipated outward away from longitudinal axis, radially outward and over the steps, ridges and/or taper of the flange  52 R and into the interior of the bore  65 B. There, they collide with the internal surfaces of the base of that module and swirl around between the front portion of the flange and the rearward wall  52 RW of the base of the next forward baffle module  52 . Because of these multiple various collisions with the surfaces in the baffle modules, there are more opportunities for the propellant gases to be diverted, delayed, cooled, or otherwise impeded before further travel through the suppressor. The gases also continue to extend and travel along the first gas pathway GP 1 , entering each respective baffle module and colliding with the stepped cones or ridged or tapered flanges of each subsequent baffle module until eventually a small portion escapes out the bullet opening  30 O of the forward end cap insert  30 . 
     Separate and distinct from the first gas pathway GP 1 , gases also travel along a second gas pathway GP 2 . Initially, when the gases escape the expansion chamber tube  80 , they encounter the blast baffle  70  first, within the interior  20 I of the baffle tube  20 . In particular, the propellant gases diffuse around the webs  73 W of the blast baffle  70  and are channeled via the angled or curved, inwardly flared rear surface  73 R of the ring  73  into the secondary ports  73 P. The gases that extend and pass through the secondary ports  73 P are those that embark upon the second gas pathway GP 2 . In particular, the gases expanding along this second gas pathway GP 2  pass through the secondary ports  73 P, around the webs  73 W, over the exterior of the inner core  72 , up and over the ramped surface  71 A and over the exterior  71 G of the base  71 . From there, the gases traveling along this second gas pathway extend over the exteriors of the adjacent baffle modules. 
     For example as shown in  FIG. 7 , the gases along the gas pathway GP 2  extend up over the ramped surface  67 , into the grooves  65 G, being directed in the helical path of the baffle module  60 , and thus swirling helically around the baffle module in the grooves  65 G until exiting the helical grooves and traversing across the generally flat or cylindrical exterior  61 E of the module  60 . On or along this portion of the baffle module, the gases travel generally linearly toward the next set of helical grooves of the next baffle module and so on, as described above. Optionally, while travelling on the second gas pathway GP 2 , the gases travel over the exterior surfaces of the respective blast baffle and baffle modules, but generally between those exterior surfaces and the interior surface of the sidewall  20 S of the baffle tube  20 . Generally, the blast baffle and its secondary ports are in fluid communication with a second gas pathway GP 2  that is defined between the inner sidewall and the outer wall of the baffle module. 
     The various structures of the baffle stack SOBS, for example the blast baffle, baffle modules, and end insert and the like can be cast, molded, machined, or manufactured into one or more monolithic units. Optionally, the different components, such as the blast baffle, baffle modules, forward end cap, rearward end cap and/or end cap insert can be cast, molded, machined or manufactured as combined or integral single piece units, each unit having two or more components joined with one another permanently, rather than via a threaded connector interface as shown in the current embodiments. 
     As mentioned above, the suppressor  10  of the current embodiments can be configured to join with and/or include an optional over the barrel expansion tube or chamber  90 . Referring to  FIGS. 11-12 , the tube  90  is configured to extend rearward from the expansion chamber tube  80  and/or blast tube  20 , over a portion of the barrel of the firearm to which the suppressor  10  is joined. With this over the barrel expansion tube  90 , the expansion chamber, and total volume of the suppressor for dissipating, and capturing expanding propellant gases can be increased, without extending the length of the suppressor beyond the end of the muzzle. This can be helpful where the suppressor is to be used on firearms in tight spaces or within building structures. 
     The suppressor  10  can include the baffle tube  20 , expansion chamber tube  80 , the respective compression nut  25  and the other components described above, for example, the baffle modules  51 ,  52 ,  60 , blast baffle  70 , forward end cap  40  and forward end cap insert  30 . The suppressor  10  however does not include the rear end cap  86  joined with the exterior of the muzzle interface  83 , or the expansion tube  80  in general. 
     As shown in  FIG. 11 , the muzzle interface  83  is still configured to be joined with a muzzle of the firearm. Instead of the rearward end cap  86 , the over the barrel expansion chamber or tube  90  is joined with the rearward portion of the expansion chamber. It will be noted here that the end  86  can be rapidly and easily removed manually or with a special tool and replaced with the over the barrel expansion tube  90 , without destroying or otherwise substantially disassembling the suppressor  10 . This can provide modularity to the suppressor and can enable it to be used on a variety of different weapon systems. Further, with the system, a user can selectively utilize the suppressor with or without the over the barrel expansion chamber. For example, the over the barrel expansion tube  90  is removably coupled to the expansion chamber tube so that the over the barrel expansion tube can be replaced with a rearward end cap to close the expansion chamber tube with the over the barrel expansion tube no longer associated with the suppressor  10 . 
     As shown in  FIGS. 11 and 12 , the over the barrel expansion tube  90  can be joined with the expansion chamber tube  80 . The over the barrel expansion tube  90  can include a forward end  91  and a rearward end  92 . The forward end  91  can be joined with the expansion chamber tube  80 , and the rearward end  92  can be closed off with a portion of the tube as described below. The over the barrel expansion tube  90  can include an inner tube  94  configured for placement adjacent the barrel and an outer tube  95  disposed outward and around the inner tube. The over the barrel expansion tube can extend rearward from a muzzle of the firearm over its barrel B a preselected distance while the elongate baffle tube is configured to extend forward of the muzzle. The over the barrel expansion tube  90  can define an internal expansion chamber  90 I. This over the barrel chamber  90 I can be in fluid communication with the expansion chamber  80 , and in particular, its internal chamber  80 I via one or more ports  83 P defined around and/or by the muzzle interface  83 . The inner and outer tubes can be separate parts, threadably joined with one another as shown, or alternatively, the tubes can be integrally formed so that the over the barrel expansion chamber tube  90  is an integral single piece unit. As shown, however, the outer tube  95  can define an interior connector interface  95 IC adjacent the second end or rearward end  92  of the over the barrel expansion tube. The inner tube  94  can include an exterior connector interface  94 EC. These interfaces can be threaded so that the outer tube can be further coupled to the inner tube. These tubes are configured so that they are individually or both removable and replaceable relative to the expansion tube  80  and/or other parts of the baffle tube  20 . 
     The inner tube  94  can define an interior bore  94 B or cavity that extends to the muzzle interface  83  of the expansion chamber  80 . The interior bore  94 B can be sized so that fits over a barrel of a preselected size or sizes. Optionally, the inner tube can come in a variety of sizes configured to be joined with the outer tube  95 . These sizes can be dimensioned with diameters that closely fit over barrels of a variety of different sizes. With this construction of the over the barrel expansion tube  90 , a user can modify the size of the internal expansion chamber  90 I by the changing the size of the inner tube  94 . The user also can appropriately size the inner tube relative to the barrel of the weapon to which the suppressor  10  will be attached. 
     The inner tube  94 , as shown in  FIG. 11  also can be configured to include an interior connector interface  94 IC. This interior connector interface can join the muzzle interface  83  of the expansion tube  80 . In particular, the interior connector interface  94 IC can be threaded so that it will thread onto the exterior threads  83 T of the muzzle interface  83 , thereby threadably coupling these items. Optionally, the muzzle interface  83  of the expansion chamber tube  80  can extend rearward beyond the rear rim  80 RR of the expansion tube  80 . This can enable or provide a stub onto which the over the barrel expansion chamber tube  90  can be joined. 
     As shown in  FIG. 11 , and as mentioned above, the rearward rim  80 RR of the expansion tube  80  can include a rearward rim having a tapered flange that generally flares inward. The outer tube  95  can include a corresponding tapered flange at the forward rim or edge  90 F. These tapered flanges, that is, the rearward taper  80 RRT and forward taper  90 FR can engage one another when the over the barrel expansion tube  90  is joined with the expansion tube  80 . Due to the tapers of the respective tapered flanges, these components can sealingly engage one another and can seal the suppressor at the joint between the over the barrel expansion chamber tube  90  and the expansion chamber tube  80  to prevent gases from being expelled at that joint. Due to the tapered flanges at this joint, the over the barrel expansion chambers also can be brought into concentrating with the expansion chamber tube  80  and the suppressor in general. The sealing action at the joint or interface of the inner tube and the expansion chamber tube, can be enhanced by engaging an engagement portion  96  of the over the barrel expansion chamber tube  90  with a tool or manually, and tightening the tube  90  so that the inner tube threads onto the muzzle interface  83  and forcibly pushes the outer tube  95  along, so that the outer tube forward rim  90 F engages the rearward rim  80 RR, that is the tapered flanges engage one another and can seal the corresponding joint under that tightening force. Optionally, the over the barrel expansion tube  90  can be configured to include a threaded portion that threads to a corresponding threaded portion associated with the expansion tube  80  at a first location. Distal, and radially outward from the first location, the tube  90  can include a tapered flange that seats against a corresponding tapered flange of the expansion tube  80 . Upon tightening of the threads, the tapered flanges engage and optionally seal against one another at a joint between the tube  90  and tube  80 . 
     As mentioned above, when the over the barrel expansion chamber is installed, upon firing of a bullet, gases enter the internal chamber AI of the expansion chamber tube  80 . Some of those gases go forward and into the blast baffle  70  to be dissipated among the various components inside the baffle tube  20 . Some of those gases, however, expand rearwardly over into the internal chamber  90 I of the over the barrel expansion tube  90 , and expand generally rearward over the barrel of the firearm which the suppressor  10  is joined. With this increased volume effective volume of the expansion chamber plus the over the barrel expansion chamber, propellant gases can be dissipated substantially. 
     The over the barrel expansion chamber tube  90  can be joined with the remainder of the suppressor, for example, the expansion chamber tube  80  via an internal threaded coupling, associated with the inner tube  94  and the muzzle interface  83 . The exterior portion of the tube  90 , for example, the outer tube  95  can be coupled to the expansion tube  80  via a sealed joint between flanges, where surfaces of the tube  90  engage surfaces of the tube  80  under forces generated by tightening the threaded coupling at the muzzle interface. Thus, tightening of one of the inner tube or outer tube can engage the other against a part of the expansion tube  80  to seal the elements together. Of course, in some applications, the over the barrel expansion chamber tube  90  can include threads at the forward rim  90 FR that interface with additional threads disposed on the rearward rim  80 RR of the expansion tube to join these features. Further optionally, the inner tube can interface with the muzzle interface at respective sealing flanges, rather than threaded portions. A variety of other coupling configurations are contemplated to removably join the over the barrel expansion chamber tube  90  with the remainder of the suppressor  10  and its components. 
     Directional terms, such as “vertical,” “horizontal,” “top,” “bottom,” “upper,” “lower,” “inner,” “inwardly,” “outer” and “outwardly,” are used to assist in describing the invention based on the orientation of the embodiments shown in the illustrations. The use of directional terms should not be interpreted to limit the invention to any specific orientation(s). 
     The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular. Any reference to claim elements as “at least one of X, Y and Z” is meant to include any one of X, Y or Z individually, and any combination of X, Y and Z, for example, X, Y, Z; X, Y; X, Z; and Y, Z.