Abstract:
Disclosed are several examples of apparatuses for suppressing the blast and flash produced as a projectile is expelled by gases from a firearm. In some examples, gases are diverted away from the central chamber to an expansion chamber by baffles. The gases are absorbed by the expansion chamber and desorbed slowly, thus decreasing pressure and increasing residence time of the gases. In other examples, the gases impinge against a plurality of rods before expanding through passages between the rods to decrease the pressure and increase the residence time of the gases.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims a benefit of priority to U.S. Provisional Patent Application Ser. No. 61/535,574, filed 16 Sep. 2011, the entire contents of which is incorporated herein by reference as if included at length. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     This invention was made with government support under Contract No. DE-ACO5-000R22725 awarded by the U.S. Department of Energy. The government has certain rights in the invention. 
    
    
     THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
     None. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates to firearms and more specifically to a suppressor that reduces the audible blast and visual flash generated as a projectile is fired from a firearm. 
     2. Description of the Related Art 
     Firearms such as rifles, shotguns, pistols, and revolvers with integral or removable barrels function by discharging a projectile, such as a bullet, at a target. In each type of firearm, a cartridge or round is first loaded, manually or automatically, into a proximal chamber at a breech end of the barrel. Then, a firing pin strikes a primer located in the base of the cartridge casing, igniting an explosive propellant that produces highly pressurized gases to propel a projectile or bullet out of the cartridge casing. The bullet then travels within a central, longitudinal bore of the barrel and exits out a distal end called a muzzle. A series of rifling lands and grooves in the barrel introduce a twist to the bullet as it travels through the bore, stabilizing it in flight, for improved accuracy. 
     As the bullet exits the muzzle, the highly pressurized gases quickly expand into the relatively low-pressure atmosphere, producing an audible, muzzle blast and a visual, muzzle flash. During both Military and Law Enforcement operations it is advantageous to suppress the muzzle flash from potential adversaries in order to conceal a shooter&#39;s position and gain a tactical advantage. This is especially true during clandestine operations, carried out under the veil of darkness, such as when the elite U.S. Navy Seal Team 6 killed Osama Bin Laden in his Pakistani compound in 2011. During Military, Law Enforcement and Competitive Shooting operations it is also beneficial to reduce the muzzle blast in order to safeguard the shooter from temporary or permanent hearing loss. 
     Most Military and Law Enforcement assault style rifles have relatively short barrel lengths for reduced weight, enhanced maneuverability, and improved target acquisition in hostile environments. However, when using these shorter barrels, the propellant charge is still burning as the bullet exits the muzzle, causing the muzzle flash to be significantly greater than it would be with longer barrels. Since a longer barrel decreases maneuverability and increases weight, various means of reducing muzzle blast and flash of shorter barrels have been devised. 
     Firearms are known to incorporate muzzle blast suppressors and/or flash suppressors. Blast suppressors are typically designed to reduce the pressure of the gases prior to discharging into the atmosphere. One such example of a blast suppressor is disclosed in U.S. Pat. No. 7,207,258 “WEAPON SILENCERS AND RELATED SYSTEMS.” Flash suppressors are typically designed to reduce the muzzle flash from the firearm to preserve the shooter&#39;s night vision, usually by directing the incandescent gases to the sides, away from the line of sight of the shooter, and to reduce the flash visible to the enemy. Military forces engaging in night combat are still visible when firing by the enemy, especially if they are wearing night vision gear, and must move quickly after firing to avoid receiving return fire. One such example of a flash suppressor is disclosed in U.S. Pat. No. 7,861,636 “MUZZLE FLASH SUPPRESSOR.” Blast and flash suppressors are typically affixed to a firearm barrel at the muzzle end via a threaded connection. 
     Despite the teachings provided by the prior art, further improvements to muzzle flash and muzzle blast suppressors are needed to advance the state of the art and improve the survivability of law enforcement and armed forces personnel. 
     BRIEF SUMMARY OF THE INVENTION 
     Disclosed are several examples of apparatuses for suppressing the blast and flash produced as a projectile is expelled by gases from a firearm. 
     According to one example, an apparatus for suppressing the blast and flash from a firearm includes a body having a proximal end located adjacent to the firearm and an opposite, distal end. The body has a wall with an inner surface that defines a central chamber and an outer surface that defines an inner boundary of an enclosed gas expansion chamber. The wall also defines a gas-transfer port for fluidly connecting the central chamber with the gas expansion chamber. A baffle is disposed within the central chamber of the body and is proximate a gas-transfer port. The baffle has a diffuser-shaped surface for diverting the gases from the central chamber and into a gas-transfer port. A can is disposed around and spaced apart from the body wall. The can has a wall with an outer surface that is exposed to the ambient atmosphere, and an inner surface that defines an outer boundary of the gas expansion chamber such that the body wall outer surface and the can wall inner surface cooperate to define the enclosed gas expansion chamber. A rib extends between the body wall outer surface and the can wall inner surface, with the rib further defining the gas expansion chamber. In this example, the gases are directed between the central chamber and the expansion chamber via a gas-transfer port as the projectile moves from the proximal end to the distal end. 
     According to another example, an apparatus for suppressing the blast and flash produced by a projectile as it is expelled by gases from a firearm includes a body having a proximal end located adjacent to the firearm and an opposite, distal end. The body has a plurality of spaced apart rods extending between the proximal and distal ends with the rods defining a central chamber. In this example, the gases are directed from the central chamber and through the spaces between the rods as the projectile moves from the proximal end to the distal end. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       A more complete understanding of the preferred embodiments will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings where like numerals indicate common elements among the various figures. 
         FIG. 1  is a side view of a rifle with a suppressor installed in accordance with an example of the present invention; 
         FIG. 2  is a side view of a pistol with a suppressor installed in accordance with an example of the present invention; 
         FIG. 3  is an isometric sectional view of a suppressor in accordance with an example of the present invention; 
         FIG. 4  is an isometric sectional view of a suppressor in accordance with another example of the present invention; 
         FIG. 5  is an exploded view of the suppressor of  FIG. 4 ; 
         FIG. 6  is a partial sectional side view of an exemplary baffle; 
         FIG. 7  is a partial sectional side view of another exemplary baffle; 
         FIG. 8  is a partial sectional side view of yet another exemplary baffle; 
         FIG. 9  is a partial sectional side view of the exemplary baffle of  FIG. 7  illustrated in relation to adjacent exemplary baffles shown in phantom; 
         FIG. 10  is a sectional front view of the exemplary baffle of  FIG. 9  taken along line  10 - 10 ; 
         FIG. 11  is a front view of an exemplary body of a suppressor; 
         FIG. 12  is an unfolded view of the exemplary body of  FIG. 11 ; 
         FIG. 13  is a front view of another exemplary body of a suppressor; 
         FIG. 14  is an unfolded view of the exemplary body of  FIG. 13 ; 
         FIG. 15  is a front view of yet another exemplary body of a suppressor; 
         FIG. 16  is an unfolded view of the exemplary body of  FIG. 15 ; 
         FIG. 17  is a front view of yet another exemplary body of a suppressor; 
         FIG. 18  is an unfolded view of the exemplary body of  FIG. 17 ; 
         FIG. 19  is a front view of yet another exemplary body of a suppressor; 
         FIG. 20  is an unfolded view of the exemplary body of  FIG. 19 ; 
         FIG. 21  is a sectional side view of a suppressor functioning in accordance with an example of the present invention; 
         FIG. 22  is a sectional side view of a suppressor functioning in accordance with an example of the present invention; 
         FIG. 23  is a sectional side view of a suppressor functioning in accordance with an example of the present invention; 
         FIG. 24  is a sectional side view of a suppressor functioning in accordance with an example of the present invention; 
         FIG. 25  is a sectional side view of a suppressor in accordance with another example of the present invention; 
         FIG. 26  is a sectional front view of the suppressor of  FIG. 25  taken along line  26 - 26 ; 
         FIG. 27  is a sectional side view of the suppressor in accordance with another example of the present invention; and 
         FIG. 28  is a sectional front view of the suppressor of  FIG. 27  taken along line  28 - 28 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Suppressors in accordance with examples of the present invention will now be described in greater detail. Computer models of these examples were first generated using a Computer Aided Design (CAD) program before being analyzed with Computational Fluid Dynamics (CFD). The CFD results were examined and each suppressor&#39;s geometry was optimized to increase residence time and to reduce the mach number of the gases exiting the suppressor. Please note that various types of firearms are known to have different barrel lengths, use different cartridge loads, and operate at different gas pressures. For this reason, parametric manipulation of some of the claimed elements may be necessary to ensure a suppressor design is optimized for each specific application. 
     Referring first to  FIGS. 1 and 2 , a firearm  100  includes a barrel  102  for discharging a projectile at an intended target. Affixed to a muzzle end  104  of the barrel  102  is a suppressor  106  in accordance with an example of the present invention. The suppressor  106  has a proximal end  108  for affixing to the firearm  100  and an opposite distal end  110  where the projectile exits the suppressor  106 . The firearms  100  illustrated in  FIGS. 1 and 2  are exemplary and are not to be considered exhaustive in any way. Many firearm architectures have existed in the past, currently exist today, or will exist in the future. It is to be understood that all types of firearms  100  will benefit from the exemplary suppressors  106  of the present invention. 
     Exemplary suppressors  106  will now be described in more detail with reference to  FIGS. 3-5 . A body  112  has the proximal end  108  having attachment means  114  for affixing the suppressor  106  to the muzzle end  104  of a barrel  102 . The attachment means  114  may be internally machined threads (shown), a cam-lock fastener, a clamp, a set screw, or some other attachment means  114  known in the art. The distal end  110  is located opposite of the proximal end  108  and closest to the intended target. A body wall  116  has an inner surface  118  that defines a central chamber  120 , while an outer surface  122  of the body wall  116  defines an inner boundary of an enclosed gas expansion chamber  124 . The body wall  116  also defines a gas-transfer port  126  for fluidly connecting the central chamber  120  with the gas expansion chamber  124 . The body  120  is manufactured by a direct to metal (DTM) 3D printing process (preferred), investment casting, conventional machining, sheet stamping and welding, or other suitable manufacturing methods. Titanium, Aluminum, Nickel, INCONEL alloy, or other light-weight, high-strength materials may be used. 
     A baffle  128  is disposed within the central chamber  120  of the body  112  and adjacent to a gas transfer port  126 .  FIGS. 6-10  illustrate several examples of these baffles  128 . Each baffle  128  includes: an upstream, diffuser-shaped surface  130  for diverting the gases (G) from the central chamber  120  to the expansion chamber  124 ; and a downstream, diffuser-shaped surface  132  for further diverting the gases (G) from the central chamber  120  to the expansion chamber  124 . Some exemplary baffles  128  include a cylindrical-shaped inlet  134 , a cage  136 , and a series of ribs  138 . The cage  136  and ribs  138  center the baffles  128  within the body  112  and properly align the baffles  128  with respect to each other and with respect to the gas transfer ports  126 . Adjacent baffles  128  define an annular chamber  140 , best illustrated in  FIG. 9 , where the gases (G) are diverted into as the projectile (P) passes through the baffle  128 . In the examples of  FIGS. 7 and 9 , a circular airfoil  142  extends from the downstream diffuser-shaped surface  132  by a strut  144 . The airfoil  142  further defines the annular chamber  140  and further diverts the gases (G) from the central chamber  120  to the gas transfer port  126 . With the baffles  128  assembled in the body  112 , a plurality of windows  146  in the cage  136  substantially align with the gas transfer ports  126  as shown in the examples of  FIGS. 6-7 . Also, please note that a separate or integral sleeve  147  may also be used to properly space a baffle  128  from the proximal end  108  of the body  112 . The baffles  128  and sleeve  147  are manufactured by a direct to metal (DTM) 3D printing process (preferred), investment casting, conventional machining, or other suitable manufacturing methods. Titanium, Aluminum, Nickel, INCONEL alloy, or other light-weight, high-strength materials may be used. 
     A can  148  is disposed around the body  112  as best shown in  FIG. 5 . The proximal end  108  of the can  148  is affixed to the proximal end  108  of the body  112  by a two-part attachment means ( 150   a ,  150   b ) on the body  120 , and the can  148  respectively. The attachment means ( 150   a ,  150   b ) allow for disassembly of the suppressor  106  for inspection, cleaning or part replacement and may include coordinating threads (shown), a cam-lock fastener, a screw clamp, a set screw, or some other suitable attachment means. In other examples, the can  148  is permanently affixed to the body  112  by welding or some other permanent means (not shown). A distal end  110  of the can  148  includes a cylindrical port  152  for straightening the discharged gases (G) to improve the trajectory of the projectile (P) as it exits the suppressor  106 . The can  148  is formed by a wall  154  that includes: an inner surface  156  that defines an outer boundary of the enclosed gas expansion chamber  124 ; and an outer surface  158  that is exposed to the ambient atmosphere (A). Carefully note that when the suppressor  106  is assembled, the outer surface  122  of the body wall  116  and the inner surface  156  of the can wall  154  cooperate to define the enclosed gas expansion chamber  124 . The can  148  may also include an aperture (not shown) through the wall  154 , at the distal end  110 , for allowing water to drain out if the suppressor  106  is submerged. The can  148  is manufactured by a direct to metal (DTM) 3D printing process (preferred), investment casting, spinning, roll forming and welding, or other suitable manufacturing methods. Titanium, Aluminum, Nickel, INCONEL alloy, or other light-weight, high-strength materials may be used. 
     One or more ribs  160  extend between the outer surface  122  of the body wall  116  and the inner surface  156  of the can wall  154 . In some examples, a rib  160  is attached to, and extends from, the outer surface  122  of the body wall  116 . This configuration is preferred for manufacturing simplicity. In other examples, a rib  160  is attached to, and extends from, the inner surface  156  of the can wall  154 . According to one example, a rib  160  may extend, lengthwise, from the proximal end  108  to the distal end  110  of the body  112 . According to another example, a rib  160  may extend around the body  112  at a constant distance from each of the proximal end  108  and distal end  110  of the body  112 . According to yet another example, a rib  160  may extend at a variable distance from each of the proximal  108  and distal ends  110  of the body  112  in a spiral arrangement. In yet another example, a rib  160  is disposed on each side of a gas transfer port  126 . In yet another example, a rib  160  is interposed between each of a plurality of gas-transfer ports  126 . In each of the preceding examples, the one or more ribs  160  further define the volume, shape, pattern and direction of the enclosed, gas expansion chamber  124 . 
     Referring now to  FIGS. 11-20 , several, non-exhaustive, examples of a suppressor body  112  are shown. Please note that some of the views are unfolded to best illustrate the relationships between the various features located about the body  112 . The unfolded views are in no way indicative of the manufacturing methods used to make a body  112 . In the specific example shown in  FIGS. 11-12 , eight ribs  160  are interposed between eight, square-shaped, gas-transfer ports  126 . Note that pairs of the gas transfer ports  126  are symmetrically opposite one another at a constant distance from the proximal end  108  and the pairs vary circumferentially about the body  112  going towards the distal end  110 . Here, a rib  160  extends the full distance from the proximal end  108  to the distal end  110  of the body  112 . 
     In the specific example of  FIGS. 13-14 , sixteen ribs  160  are interposed among six, rectangular-shaped, gas-transfer ports  126 . One rib  160   a  is disposed at a constant distance from each of the proximal and distal ends ( 108 ,  110 ) of the body  112 . Note that pairs of the gas transfer ports  126  are symmetrically opposite one another and at a constant distance from the proximal end  108  and some of the pairs vary circumferentially about the body  112  going towards the distal end  110 . Also, please note that the gas-transfer ports  126  of this example extend across more than one of the ribs  160 . In this example, there may, or may not be, a one-to-one correspondence between the gas-transfer port  126  size and the baffle window size  146 . The baffle window  146  area may be larger than, equal to, or smaller than the corresponding gas-transfer port  126  area. 
     In the specific example of  FIGS. 15-16 , eight ribs  160  are interposed among four, round-shaped, gas-transfer ports  126 . Note that pairs of the gas transfer ports are symmetrically opposite one another and at a constant distance from the proximal end  108  and the pairs vary circumferentially about the body  112  going towards the distal end  110 . Also, please note that some of the ribs don&#39;t extend the full distance from the proximal to the distal ends ( 108 ,  110 ), creating a serpentine-shaped expansion chamber  124 . Note that the serpentine shapes of the expansion chamber  124  causes the gases (G) to reverse direction and travel the length of the body  112  twice, thus increasing the residence time. 
     In the specific example of  FIGS. 17-18 , eight ribs  160  are interposed among four, rectangular-shaped, gas-transfer ports  126 . Note that pairs of the gas transfer ports  126  are symmetrically opposite one another and at a constant distance from the proximal end  108  and the pairs vary circumferentially about the body  112  going towards the distal end  110 . Also, please note that a gas-transfer port  126  of this example extends across a rib  160 . 
     In the specific example of  FIGS. 19-20 , eight ribs  160  are interposed between eight, square-shaped, gas-transfer ports  126 . Note that pairs of the gas transfer ports are symmetrically opposite one another and at a constant distance from the proximal end  108  and the pairs vary circumferentially about the body  112  going towards the distal end  110 . Here, a rib  160  is at a variable distance from each of the proximal and distal ends ( 108 ,  110 ) in a spiral arrangement about the body  112 . 
     Modifications to the number of ribs  160 , the gas transfer port  126  number, size and location, the number and type of baffle  128 , and the expansion chamber  124  volume may be necessary to optimize a suppressor  106  for a specific firearm  100  application. Overall size and weight must also be considered when optimizing the suppressor  106  to ensure the design doesn&#39;t encumber the function or handling of the firearm  100 . 
     The operation of a suppressor  106  of the present examples will now be described in further detail with reference to  FIGS. 21-24 . An exemplary suppressor  106  is first attached to a muzzle end  104  of a barrel  102  via attachment means  114 . After the firearm  100  is aimed and the trigger is pulled, a projectile (P) is discharged from the muzzle end  104  and into the proximal end  108  of the suppressor  106 . As the projectile (P) progresses through the central chamber  120 , the pressurized gases (G) are diverted outwardly from the central chamber  120  by a baffle  128 , through a gas transfer port  126 , and into the expansion chamber  124 . The diffuser shaped surfaces  130 ,  132  of adjacent baffles  128  define an annular chamber  140  that directs the gases (G) through a window  146 , which may substantially align with the gas transfer ports  126 . Once through the gas transfer ports  126 , the gases (G) then expand to fill the expansion chamber  124 . The additional volume of the expansion chamber  124  reduces the pressure of the gases (G) according to Boyle&#39;s Law (p 1 V 1 =p 2 V 2 ), and the additional travel distance increases the residence time. The increased residence time ensures a more complete burn of the explosive charge generating the gases (G), thus eliminating or reducing the blast and flash from a firearm  100 . In addition, the increased residence time reduces the mass flow rate of the gases (G) exiting the device, thus extending the time frame that gases expel from the device, therefore lowering the energy rate of the expanding gases (G). This, in turn, reduces the acoustic level exiting the device and reduces noise. After filling the expansion chamber  124 , the gases (G) are then directed back through the gas transfer port  126  and into the central chamber  120  at a lower velocity and pressure. This sequence is repeated at each of the gas transfer ports  126  along the length of the body  112 , as the projectile (P) moves from the proximal end  108  to the distal end  110 . Note that, for conciseness, the entire sequence is not illustrated in this series of figures. 
     With reference to  FIGS. 25-28 , another exemplary suppressor  106  will now be described. The suppressor  106  has a proximal end  108  for attaching the suppressor  106  to the firearm  100  (not shown). Attachment means  114  at the proximal end  108  may be internal threads (shown), a cam-lock fastener, a clamp, a set screw, or some other attachment means. Opposite the proximal end  108  is a distal end  110  where the projectile (P) exits the suppressor  106  and is directed towards the intended target. 
     In this example, a central chamber  120  is defined by a plurality of rods  162  extending lengthwise between the proximal and distal ends  108 ,  110 . The rods  162  may be solid (as shown) or tubular (not shown) and are disposed in close proximity to one another around the central chamber  120 . Carefully note that adjacent rods  162  do not actually touch one another. The rods  162  shown in the figures have a circular cross section, but other cross sectional shapes are contemplated. The diameters of the various circular rods  162  may be the same or may be different. In the illustrated example, the diameters of the rods  162  closest to the central chamber  120  are smaller than the diameters of the rods  162  furthest away from the central chamber  120 . Concentric layers of side-by-side rods  162  extend outwardly from the central chamber  120 , defining expansion passages  164  that extend away from, and about, the central chamber  120  in a tortuous path between the rods  162 . 
     In some examples, a frustoconical-shaped baffle  128 , having a central inlet  134  and extending outwardly from the central chamber  120 , intersects the rods  162 . The baffle  128  directs the gases (G) away from the central chamber  120  at the rods  162  and into the expansion passages  164 . In other examples, there are multiple baffles  128  spaced apart from one another between the proximal and distal ends  108 ,  110 . In some examples, the baffles  128  are equally spaced apart from one another and in other examples the baffles  128  are not equally spaced apart from one another. In the example of  FIG. 27 , the baffles  128  closest to the proximal end  108  are spaced apart from one another by a first spacing distance and the baffles  128  closest to the distal end  110  are spaced apart from one another by a second spacing distance that is greater than the first spacing distance. 
     The operation of a suppressor  106  of the present example will now be described in detail with reference to  FIGS. 25-28 . An exemplary suppressor  106  is first attached to a muzzle end  104  of a barrel  102  via attachment means  114 . After the trigger is pulled, a projectile (P) is discharged from the muzzle end  104  and into the suppressor  106 . As the projectile (P) progresses through the central chamber  120 , the pressurized gases (G) are diverted outwardly from the central chamber  120  and impinge against the layers of rods  162 . The gases (G) are then directed through the tortuous paths of the expansion passages  164  disposed between the rods  162 . Note that the baffles  128  further divert the gases (G) away from the central chamber  120 . The gases (G) continue away from the central chamber  120 , until they discharge into the atmosphere (A) around the suppressor  106 . The expansion passages  164  increase the residence time and reduce the pressure of the gases (G), thus reducing the muzzle blast and flash. If the suppressors of the present example are submerged, the water will simply flow out of the expansion passages  164 . 
     The suppressors  106  described in the preceding examples were made using a direct to metal (DTM) 3D printing process. Titanium, Aluminum, Nickel, INCONEL alloy, or other light-weight, high-strength materials may be used. Because all the elements, such as the rods  162 , baffles  128 , proximal end and distal end, intersect each other, the suppressor  106  is a monolithic structure and cannot be nondestructively disassembled. These examples are light weight and cost effective. 
     The suppressors described above were tested on a 5.56 caliber rifle (AR-15/M4) and a 7.62 caliber rifle (SR-25/M110) and compared to conventional flash hiders and suppressors. The setup included accurate placement of microphones at 45 degrees, 90 degrees and 170 degrees (ear level) to the barrel centerline. 
     For the 5.56 caliber rifle test, sound pressures were compared at 45 degrees and 90 degrees to the barrel centerline. Data was recorded at 51,200 hz and acoustics were calculated for 5000 samples after triggered data. The test results are shown in Table 1 below. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 5.56 (AR-15/M4) Rifle 
               
             
          
           
               
                   
                 Apparatus Tested 
                 90 Degree [db] 
                 45 Degree [db] 
               
               
                   
                   
               
               
                   
                 Company A Flash Hider 
                 150.4 
                 151.6 
               
               
                   
                 Company A Suppressor 
                 129.8 
                 140.9 
               
               
                   
                 Company B Suppressor 
                 130.1 
                 138.8 
               
               
                   
                 Suppressor of FIG. 3 
                 129.5 
                 138.3 
               
               
                   
                 Suppressor of FIG. 4 
                 127.2 
                 136.6 
               
               
                   
                   
               
             
          
         
       
     
     For the 7.62 caliber rifle test, sound pressures were measured at 45 degrees and 90 degrees to the barrel centerline. Data was recorded at 51,200 hz and acoustics were calculated for 5000 samples after triggered data. The test results are shown in Table 2 below. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 7.62 (SR-25/M110) Rifle 
               
             
          
           
               
                   
                 Apparatus Tested 
                 90 Degree [db] 
                 45 Degree [db] 
               
               
                   
                   
               
               
                   
                 Company A Flash Hider 
                 150.7 
                 151.0 
               
               
                   
                 Company A Suppressor 
                 132.7 
                 144.1 
               
               
                   
                 Company B Flash Hider  
                 151.3 
                 151.5 
               
               
                   
                 Company B Suppressor 
                 135.1 
                 144.9 
               
               
                   
                 Suppressor of FIG. 3 
                 128.7 
                 140.4 
               
               
                   
                   
               
             
          
         
       
     
     The maximum Mach number of the gases exiting the exemplary suppressors was also calculated with CFD and compared to a commercial suppressor. The results of the Mach number tests are shown in Table 3 below. 
     
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Mach number Test Results 
               
             
          
           
               
                   
                 Apparatus Tested 
                 Mach Number 
               
               
                   
                   
               
             
          
           
               
                   
                 Company A Flash Hider 
                 &gt;5.0 
               
               
                   
                 Company B Suppressor 
                 &gt;5.0 
               
               
                   
                 Suppressor of FIG. 3 
                 0.56 
               
               
                   
                 Suppressor of FIG. 27 
                 1.4 
               
               
                   
                   
               
             
          
         
       
     
     While this disclosure describes and enables several examples of firearm suppressors, other examples and applications are contemplated. Accordingly, the invention is intended to embrace those alternatives, modifications, equivalents, and variations as fall within the broad scope of the appended claims. The technology disclosed and claimed herein is available for licensing in specific fields of use by the assignee of record.