SSS.6.162 - Combat Application Technologies CAT/SC/B1 and the HK P30L
/Combat Application Technologies CAT/SC/B1 on the HK P30L Full-Size Semiautomatic Pistol
The CAT/SC/B1 (“SC” in this report) is designed by Combat Application Technologies (CAT). It is a 9mm centerfire pistol silencer, intended to suppress the 9x19mm cartridge from semiautomatic handguns. The SC is a modular silencer with a 1.38-inch primary diameter, and its long configuration is 7.5 inches in length. In its short configuration, the silencer is 5.5 inches in length. These lengths include the internal inertial-decoupling piston possessing 1/2-28tpi or 13.5x1mm LH threading. Users should note that the CAT SC is compatible with its own pistons, as well as those from SilencerCo and CGS Group. Performance and operability differentials may occur with varying the piston type. Users should note that although CGS Group MOD 9 3-Lug adapter may thread into the CAT SC, that adapter is not compatible nor supported by the manufacturer, and damage may result. The SC is a pistol silencer, not a submachinegun silencer. The entirety of the two silencer body sections are DMLS (3D-printed) from a proprietary Titanium alloy; the rear and front end caps are constructed from machined titanium. The silencer is user-configurable, and with the piston and spring installed, weighs 9.1 ounces in the long configuration and 7.2 ounces in the short configuration, as tested. The SC can be obtained from Silencer Shop.
PEW Science is an independent private testing laboratory and also hosts the world’s only independent public suppressed small arms research cooperative. Testing, data analysis, and reporting is generated with funding provided by PEW Science members. Any test data that is generated with any portion of private funding contains this disclosure. The testing and analysis production for this Sound Signature Review was funded in part by PEW Science Project PEW-CAT-059-004-24. Therefore, data pertaining to the CAT/SC/B1 in this Sound Signature Review is published with the express written permission of Combat Application Technologies.
This Sound Signature Review contains test results and analysis for two silencer configurations in two tests. Test data was generated using the CAT/SC/B1 (Long and Short) on the HK P30L full-size semiautomatic pistol, chambered in 9mm with a 5-inch factory HK threaded barrel. Speer Lawman 147gr ammunition was used in the test.
Section 6.162.1 contains the SC test results and analysis in the long configuration.
Section 6.162.2 contains the SC test results and analysis in the short configuration.
Section 6.162.3 contains Suppression Rating comparisons of the SC with the SilencerCo Omega 9K, Inert Haze Ti-P, AAC Ti-RANT 9M-HD, AAC Ti-RANT 9M, AAC Ti-RANT 9, HUXWRX CA$H 9K, Resilient Suppressors RSP, CGS MOD9 FS, Rugged Obsidian 45, and SWR Trident-9 silencers, fired on the Heckler and Koch P30L.
Section 6.162.4 contains the review summary and PEW Science laboratory staff opinions.
Summary: When paired with the HK P30L full-size semiautomatic pistol and fired with Speer Lawman 147gr ammunition in its long configuration, the CAT/SC/B1 achieved a Suppression Rating™ of 64.6 in PEW Science testing. In its short configuration with the same host weapon and the same ammunition, the CAT/SC/B1 achieved a Suppression Rating of 50.7. As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.
Relative Suppression Rating Performance is Summarized in SSS.7 - PEW Science Rankings
6.162.1 CAT/SC/B1 (Long) Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the CAT SC in its long configuration tested on the HK P30L is shown in Table 1. The data acquired 1.0 m (39.4 in) left of the muzzle is available for viewing to all. This is a members-only review and includes pressure and impulse waveforms measured at the shooter’s ear. PEW Science thanks you for your support; further testing, research, and development of PEW-SOFT and the Silencer Sound Standard is made possible by members like you!
Table 1. CAT/SC/B1 (Long Configuration) Sound Metric Summary
6.162.1.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 6-shot test acquired with PEW-SOFT™ are shown below. Six cartridges were loaded into the magazine and the weapon was fired until the magazine was empty, and the slide locked back on the slide-release lever actuated by the follower of the empty magazine. Only five shots are considered in the analysis. The signatures of Shot 6 are displayed in the data presentation but are not included in the analysis to maintain consistency with the overall PEW Science dataset. The waveforms are not averaged, decimated, or filtered. The data acquisition rate used in all PEW Science testing is 1.0 MS/s (1 MHz). The peaks, shape, and time phasing (when the peaks occur in relation to absolute time and to each other) of these raw waveforms are the most accurate of any firearm silencer testing publicly available. PEW-SOFT data is acquired by PEW Science independent testing; the industry leader in silencer sound research. For more information, please consult the Silencer Sound Standard.
The primary sound signature pressure histories for all 6 shots with the CAT SC in its long configuration are shown in Figure 1a. The sound signatures of Shot 1 and Shot 2 are shown in Figure 1b, in early time. The real sound impulse (momentum transfer potential) histories from the same 6-shot test are shown in Figure 2a. In Figure 2b, a shorter timescale is shown comparing the impulse of Shot 1, Shot 2, and Shot 3.
Fig 1a. CAT/SC/B1 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 1b. CAT/SC/B1 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Sound Pressure Signature
Figure 2a. CAT/SC/B1 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
Figure 2b. CAT/SC/B1 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
The CAT/SC/B1 represents a significant departure from common centerfire pistol technology. There are several design features of the SC specifically intended to maximize the holistic signature suppression performance on 9mm reciprocating handgun systems. The HK P30L standard 9x19mm semiautomatic pistol test host, like many common reciprocating centerfire handguns, possesses a locking tilting-barrel action. It is on these systems that the performance of the CAT SC is intended to excel. The long configuration of the CAT SC demonstrates several unusual performance characteristics, as displayed in the measured free field blast overpressure signatures above. These characteristics include:
Unusually low blast pressure amplitude throughout initial jetting, primary blowdown, and ground reflection (Fig. 1a).
Relatively typical duration of slide return-to-battery (Fig. 1a).
Extremely minimal FRP jetting, both in amplitude and time to normalize (Fig. 1b).
Gross signature normalization, of all shots, in very early time (Fig. 1b and Fig. 2a).
Apparent blast loads from system breach accumulating momentum in early time, due to the significantly low relative primary muzzle blast amplitude noted in (1), (Fig. 2b).
Highly unusual blast impulse accumulation for the pressure amplitude regime; the momentum transfer rate decreases after initial jetting, resulting in significant slope change (Fig. 2a, after ~30 ms).
The above performance indicators from the measured test data support the conclusion that the CAT SC is operating differently than traditional pistol silencers on a typical centerfire handgun host weapon system. And, another highly unusual attribute to note is that the CAT SC accomplishes all of the above with the addition of a significantly high early time flow rate and reduced net backpressure. This type of behavior is truly unprecedented in PEW Science laboratory testing on this weapon system. These combined performance attributes are possible due to the combined technologies implemented in the CAT SC; its design uses CAT SB-SHOCK technology; a specific adaptation combining elements of SURGE BYPASS with DiVerge technologies for centerfire handgun use.
PEW Science Research Note 1: As discussed in the CAT MOB submachinegun suppression evaluation (6.148), CAT DiVerge, SURGE BYPASS, and SNIPER2 technologies are contained within CAT’s SkyNET design vectors, and are each utilized to achieve different performance characteristics on the requisite weapon system platforms. Like SURGE BYPASS, DiVerge, and SNIPER2, SB-SHOCK is also classified as a hybrid design in the PEW Science taxonomy. The combination of technology characteristics used to implement SB-SHOCK significantly differentiate its function.
Similar to CAT DiVerge designs, silencers implementing SB-SHOCK are optimized for the lower combustion pressures of centerfire pistol cartridges. In the CAT MOB, the DiVerge technology regulates the varied low pressure conditions throughout each stage of the silencer, for applications in which maximum signature suppression is paramount. Flow rate is maintained in early time, with significant external gas momentum throttling in a consistent time regime. Another SkyNET design vector, CAT SB-SHOCK allows for this same behavior in a significantly reduced system size by combining elements of SURGE BYPASS with DiVerge to maximize efficiency in early time, prior to precursor flow exit and well before primary jetting. By taking advantage of early internal precursor wave shape factors in a defined proximity to the first reflector, SB-SHOCK ensures early venting can occur in a relatively forgiving window of pressure amplitude while additive impulse from precursor shocks stays below a critical threshold. A significant benefit of this behavior in the CAT SC is a purposeful higher early time flow rate (lower back pressure) on semiautomatic handguns which significantly increases the level of protection to the operator. Another significant benefit is the level of performance that is possible when shortening the silencer (see Section 6.162.2). Perhaps just as significant, is the level of pure muzzle suppression that is possible with the technology and demonstrated with the CAT SC.
PEW Science Research Note 2: The gross muzzle suppression performance of the CAT SC in the long configuration, in the free field, is astoundingly high. The silencer in its long configuration is 7.5 inches long. Its muzzle Suppression Rating is 64.3. This performance is almost a full category higher than that of the CGS MOD 9 FS (6.6), which is an extremely high performance pistol silencer with significant back pressure, possessing a muzzle Suppression Rating of 55.2. Even the most refined and mature iteration of the AAC Ti-RANT 9; the Ti-RANT 9M-HD in its long configuration (6.118), is far outclassed by the CAT SC, achieving a muzzle Suppression Rating of 54.4. This level of pure suppression performance differential is nontrivial. Users should note that these performance metrics are measured and calculated using a full-power self defense ammunition analog. The Speer Lawman 147gr loading used in the 9x19mm Silencer Sound Standard research pedigree is not down-loaded for silencer use. Although subsonic, the loading is full-power intended to mimic the ballistics of defense rounds of the same bullet weight. The choice of this loading balances performance demonstration of the subsonic ammunition combustion regime with the conservatism of full power commercial ammunition for public data and analysis utility.
PEW Science Research Note 3: As discussed in detail in the full Member Version Section 6.162.1.2, the performance highlighted in Research Note 2 is even more unusual considering the performance of the CAT SC at the shooter’s ear. The Suppression Rating at the system operator’s head, in the free field, with the long configuration of the CAT SC, is an unprecedented 49.1. This level of operator protection, in the free field, with the full (long configuration) of a high performance silencer is highly unusual. For context, examples of silencers with low backpressure, intended to maximize shooter protection in the free field, include models such as the HUXWRX CASH 9K (6.96), the Resilient Suppressors RSP (6.87), and adjacently, the Inert Haze Ti-P (6.145). These three silencers achieve operator Suppression Ratings in the free field ranging from 42.3 to 45.1. And, their muzzle Suppression Ratings suffer due to higher distal flow rate. The long configuration of the CAT SC achieves an operator Suppression Rating in the free field of 49.1; almost half a category higher than the nearest competitor, with an aforementioned muzzle Suppression Rating that is significantly higher. The whole sound field experiences significant suppression with the CAT SC, and the performance combination for operators and bystanders is both unprecedented and seemingly uncompromising, when taken in context of the above. FRP severity differential with the CAT SC is postulated to be noticeable to bystanders, but its severity is significantly lower than even the lowest severity shots from other high performance silencers on this platform.
PEW Science Research Note 4: There do exist some high performance 9mm pistol silencers outside the currently published Silencer Sound Standard research pedigree that have market proliferation. Internal PEW Science testing of some such systems has been performed and performance analysis for such silencers is the subject of future publications. Regardless of these current and temporary omissions from the public pedigree, the current published dataset contains a broad demonstration and examination of common technologies. PEW Science encourages the reader to consider this fact for context when examining the performance discussed in this report. There are also, for example, commonly fielded over-bored silencer evaluations on the platform that exist, such as the Rugged Obsidian 45 (6.7). The performance evaluation of that silencer on this platform illustrates how even with significant primary axial bore flow rate, pistol silencer backpressure on semiautomatic handguns must be addressed with advanced technology to maximize operator protection in the free field. That report is an inherent standalone case study examining how both bore size and silencer length influence protection differentials. Further bore-size variable examination of that silencer technology in the taxonomy is forthcoming.
PEW Science Research Note 5: As in most semiautomatic weapon testing, a second pressure pulse originates from the ejection-port signature of the weapon and it occurs early enough in time such that its waves coalesce with that of the muzzle signature. However, in late time (at approximately 76 ms in Figure 1a) the mechanical noise of the slide closing is observed. The pressure signature of Shot 6 does not display this event due to the slide remaining locked to the rear after the sixth and final round is fired from the magazine.
The shape, timing, and magnitudes of the early-time pressure pulses and overall shape of the impulse waveforms measured at the muzzle, from shot-to-shot, are relatively consistent. The consistency of the waveform amplitudes highlight the silencer’s overall sound performance consistency at the muzzle after the FRP, as well as the relative consistency of the tested semiautomatic firearm configuration.
PEW Science Research Note 6: Note that the muzzle Suppression Rating of the CAT SC in its long configuration used on the full-size HK P30L semiautomatic handgun test host is 64.3 and the shooter’s-ear Suppression Rating is 49.1; which are different zones on the Suppression Rating Dose Chart. The gross suppression of a silencer, as well as its flow rate, influences the holistic signature on a semiautomatic host weapon. The signatures measured at the shooter’s ear are presented and examined below.
6.162.1.2 SOUND SIGNATURES AT SHOOTER’S EAR
Real sound pressure histories from the same 6-shot test of the CAT SC in its long configuration acquired with PEW-SOFT at the shooter’s ear are shown below. Again, the waveforms are not averaged, decimated, or filtered. The data acquisition rate used in all PEW Science testing is 1.0 MS/s (1 MHz).
The primary sound signature pressure histories at the ear for all 6 shots are shown in Figure 3. The primary sound signature history is shown in Figure 3a. A zoomed-in timescale is displayed in Figure 3b, in the region of peak sound pressure for Shot 1, Shot 2, and Shot 3. The real sound impulse (momentum transfer potential) histories at the ear from the same 6-shot test are shown in Figure 4. Again, full and short timescales are shown.
Figure 3a. CAT/SC/B1 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Pressure Signature
Figure 3b. CAT/SC/B1 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Pressure Signature, Short Time Window
Figure 4a. CAT/SC/B1 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Impulse Signature
Figure 4b. CAT/SC/B1 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Impulse Signature Peaks
There is a persistent observed phenomenon present in centerfire pistol silencer signatures when using the HK P30L standard test host. As discussed in previous publications, an early-time shock load propagates from the weapon breach prior to full propagation of the muzzle blast signature to the operator’s location. PEW Science postulates that the so-called modified tilting-barrel Browning action present in many modern semiautomatic handguns is susceptible to this phenomenon due to its locking resistance early in the displacement-time kinematic cycle. PEW Science previously postulated that this phenomenon may be more prevalent during the use of pistol silencers exhibiting relatively higher early-time flow restriction (back pressure). With the publication of this report, it appears that this postulation was incorrect. Even with the extremely high early-time flow rate of the CAT SC, these short duration shock loads from the weapon breach still occur; regardless of long or short silencer configuration, as well (see Member Section 6.162.2.2). These shocks can be seen in Figure 3a at approximately 28.5 ms. They occur in Shot 3, Shot 4, and Shot 6, and to a lesser extent in Shot 5. They do not occur in Shot 1 or Shot 2.
PEW Science Research Note 7: Subsequent momentum transfer potential (impulse) generation from the aforementioned breech shocks are displayed in Figure 4. Note that these impulse events occur for a relatively short duration at relatively low amplitude. PEW Science analysis of these signatures does not indicate adverse severity to the operator during Shots 3, 4, 5, or 6. Shot 1 presents as the most severe to the shooter, with Shot 5 being the least severe. The events that occur post-breech-shock are more influential to hearing damage dose than are the early shocks themselves. This finding is important, because of the low amplitude of the CAT SC signatures across the sound field. If, instead, the early shocks were found to be a more significant contributor to overall signature severity, an administrative decision regarding future test host selection could possibly be initiated. Current findings indicate a deviation from the standard HK P30L host is not needed and its use will continue for the public research pedigree.
PEW Science Research Note 8: Relative FRP severity differential at the operator’s head is postulated to be somewhat noticeable to the operator, but like the FRP severity at the muzzle, the severity with the CAT SC is significantly lower than even the lowest severity signatures from other silencers on the platform. FRP is simply not an issue with the CAT SC on a semiautomatic pistol. This is a significant performance achievement.
PEW Science Research Note 9: For significant performance context, the user is encouraged to examine and compare the measured signatures at the shooter’s ear from the Resilient Suppressors RSP (6.87) to that of the CAT SC. The RSP exhibits a shooter’s ear Suppression Rating of 45.1; the closest competitor to the long configuration of the CAT SC in the free field (other than the short configuration of the CAT SC; the subject of the next section in this report). There are significant differences between the SC and RSP operator signatures. These differences include:
Significant primary muzzle blast propagation differential. The distal blast propagation from the RSP is significantly more severe than that from the SC. Reference blast pressure amplitude at approximately 31 ms, for example, in Figure 3b of each report.
Mechanical shock signatures are less severe with the SC (~35 ms, Fig. 3b).
Positive phase impulse amplitudes are less severe with the SC (~30 ms, Fig. 4b).
The CAT SC is able to maximize protection through the entire sound field through exceptionally high early time flow rate and superior distal flow control. There exist no other comparable systems of this size on this platform, evaluated by PEW Science, to date.
The difference in performance, to the weapon operator, between the CAT SC and other silencers, is significant in the free field. Outside of the free field, near reflecting surfaces, the performance differential may be even more significant, as its holistic pressure field is so suppressed. Silencers that perform well at the shooter’s ear in the free field, like the RSP, Ti-P, and CASH 9K may be even more eclipsed by the CAT SC in performance indoors. This type of study is the subject of future research.
It is important to emphasize how much higher the performance of the CAT SC is, at the operator’s head, in the free field, than some other high performance silencers like the AAC Ti-RANT 9 family. The whole signature, from FRP to the last shot in the magazine, is not comparable. There exists an entire Suppression Rating category differential between these two systems, in performance, to the operator. This type of performance differential, existing with mechanical action noise present, is extremely unusual.
The performance of the CAT SC in its long configuration on a pistol, at the shooter’s ear, is driven by both muzzle signature and ejection port signature. Even with its high early time flow rate (lower back pressure), changing it to its short configuration by removing the front section changes the signature balance. This is demonstrated in the following section.
6.162.2 CAT/SC/B1 (Short) Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the CAT SC in its short configuration is shown in Table 2. The data acquired 1.0 m (39.4 in) left of the muzzle is available for viewing to all. As stated in Section 6.162.1, this is a members-only review and includes pressure and impulse waveforms measured at the shooter’s ear. PEW Science thanks you for your support; further testing, research, and development of PEW-SOFT and the Silencer Sound Standard is made possible by members like you!
Table 2. CAT/SC/B1 (Short Configuration) Sound Metric Summary
6.162.2.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 5-shot test acquired with PEW-SOFT™ are shown below. The waveforms are not averaged, decimated, or filtered. The data acquisition rate used in all PEW Science testing is 1.0 MS/s (1 MHz). The peaks, shape, and time phasing (when the peaks occur in relation to absolute time and to each other) of these raw waveforms are the most accurate of any firearm silencer testing publicly available. PEW-SOFT data is acquired by PEW Science independent testing; the industry leader in silencer sound research. For more information, please consult the Silencer Sound Standard.
The primary sound signature pressure histories for all 6 shots with the CAT SC in its short configuration are shown in Figure 5a. The sound signatures of Shot 1 and Shot 2 are shown in a shorter time window in Figure 5b. The real sound impulse (momentum transfer potential) histories from the same 6-shot test are shown in Figure 6a. In Figure 6b, a shorter timescale is shown comparing the impulse of Shot 1 to that of Shot 2 and Shot 3.
Fig 5a. CAT/SC/B1 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 5b. CAT/SC/B1 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 6a. CAT/SC/B1 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
Fig 6b. CAT/SC/B1 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
The removal of the distal section of the CAT SC to adapt it from its long to short configuration appreciably changes its signature on the standard HK P30L test host. There are several notable signature differentials, including:
Higher gross free field blast pressure amplitude (Fig. 5a).
More expedient blowdown and subsequent higher amplitude and decoupled ground reflection (Fig. 5a).
More developed precursor amplitude (Fig. 5b).
More severe coupled primary jetting and subsequent rarefaction (Fig. 5b).
Corresponding early-time momentum accumulation in impulse space (~29.9 ms, Fig. 6b)
More expedient rise to maximum positive phase impulse throughout the entirety of primary distal flow (Fig. 6a).
More significant FRP divergence in both pressure and impulse space.
These differentials lower the pure muzzle suppression performance of the CAT SC in its short configuration when compared to that of its long configuration, on this platform, in the free field. However, there are distinct differences between the short configuration signatures and those of other “short” silencers tested and analyzed to date.
PEW Science Research Note 10: The muzzle Suppression Rating of the CAT SC, in the free field, changes from 64.3 to 41.9 when changing from its long to short configuration. The short configuration of the SC is 5.5 inches long, and this performance differential is somewhat expected. Somewhat unexpected is the differential between this performance and larger systems, such as the aforementioned Resilient Suppressors RSP, and the short configurations of all of the other silencers tested in the pedigree. For example, the short configuration(s) of the modular AAC Ti-RANT variants are all almost half an inch longer than the short configuration of the CAT SC. And, all of these silencers have lower early-time flow rates than the CAT SC. The net result, using the CAT SB-SHOCK technology, is an again superior suppressed free field signature severity with the added benefit of further reduced operator hazard.
The short configuration of the CAT SC is approximately half an inch longer than the SilencerCo Omega 9K (6.153). However, the level of protection to the operator with the CAT SC is significantly higher than that of the Omega 9K. This is despite their muzzle Suppression Ratings being closer on this platform. The SilencerCo Omega 9K has significantly higher back pressure.
PEW Science Research Note 11: The operator hazard reduction with the short configuration of the CAT SC, in the free field, is very high. As discussed in detail in the full Member Version Section 6.162.2.2, the already high early time flow rate from the long configuration of the CAT SC is increased even further by removing the distal section. This change almost nullifies ancillary ejection port blast wave coalescence when compared to the use of other silencers on this host weapon. With a free field shooter’s ear Suppression Rating of 49.8, nominally higher than the long configuration’s 49.1, the short configuration of the CAT SC provides the highest level of operator protection in the free field of any pistol silencer evaluated by the PEW Science laboratory on this host weapon, to date. It is extremely important to note that the shooter’s ear Suppression Rating is calculated from free field blast overpressure data adjacent to the operator’s head. Environmental changes and deviations from free field conditions can, and most likely will, result in protection differentials that shift. Severe environmental differentials may provide severity with highly nonlinear characteristics and outcomes. PEW Science highly encourages examination of the full member version of this report for elaboration on these performance facts.
The FRP on this platform, with the short configuration of the CAT SC, produces a more significant severity differential when compared to subsequent shots than does the long configuration of the silencer. This is primarily due to the lack of late time FRP control from the removal of the distal section of the silencer; it is no longer operating at full efficiency. Nonetheless, the FRP severity differential with the short configuration of the CAT SC is not severe. The overall shape of the impulse waveforms measured at the muzzle, from shot-to-shot, are extremely consistent, highlighting the silencer’s overall sound performance consistency at the muzzle after the FRP, as well as the relative consistency of the tested semiautomatic firearm configuration.
PEW Science Research Note 12: Both early time flow parameters (alpha) and gross flow parameters (Omega) influence weapon behavior. This report is an examination of the influence of changing Omega while keeping alpha constant; the change in configuration from long to short configuration of the CAT SC.
6.162.2.2 SOUND SIGNATURES AT SHOOTER’S EAR
Real sound pressure histories from the same 6-shot test acquired with PEW-SOFT at the shooter’s ear are shown below. Again, the waveforms are not averaged, decimated, or filtered. The data acquisition rate used in all PEW Science testing is 1.0 MS/s (1 MHz).
The primary sound signature pressure histories at the ear for all 6 shots with the CAT SC in its short configuration are shown in Figure 7a. A zoomed-in timescale is displayed in Figure 7b, in the region of peak sound pressure. The real sound impulse (momentum transfer potential) histories at the ear from the same 6-shot test are shown in Figure 8.
Figure 7a. CAT/SC/B1 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Pressure Signature
Figure 7b. CAT/SC/B1 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Pressure Signature
Figure 8a. CAT/SC/B1 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Impulse Signature
Figure 8b. CAT/SC/B1 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Impulse Signature
Immediately, it is apparent that the gross flow rate (Omega parameter) change has influenced the signature at the shooter’s ear. The duration of positive phase impulse is lower with the short configuration that with the long configuration (reference Fig 8a, above, and Fig 4a in the preceding test).
PEW Science Research Note 13: Nonetheless, early-time shock dynamics remain constant. Therefore, the same breech pressure leaks present; again subsequent to FRP, and additionally in Shot 2. As previously stated in 6.162.1.2, even with the extremely high early-time flow rate of the CAT SC, these short duration shock loads from the weapon breach still occur; regardless of long or short silencer configuration. They are a property inherent to the HK P30L test host. And, as also discussed, they do not appear to appreciably influence shooter hazard with this silencer. Their subsequent impulse accumulations are shown in Figure 8; relatively consistent for a seemingly inconsistent host weapon combustion propagation phenomenon.
PEW Science Research Note 14: The positive phase impulse durations are strikingly different with the short configuration of the silencer, compared with that of the long configuration. The ejection port blast wave coalescence has been mostly removed, and simultaneously, the muzzle blast blowdown rate has increased, lowering the duration of impulse accumulation from that event. Combined with the tertiary benefit of high early time flow rate inherent to the system design with the CAT SB-SHOCK technology, the shooter’s ear positive phase impulse presents as a short duration plateau in Figure 8a. This signature is highly unusual, and PEW Science analysis indicates it to be of significantly less severity to operators than are most other impulsive signatures on this host, in the free field.
The determination of signature features and relative severity is extremely complex. As discussed in previous signature evaluations of modular pistol silencer systems, the consequences of dropping Omega on this particular weapon system, while keeping alpha constant, on the gross signature to the shooter, is similar hearing damage risk potential with the two silencer configurations. The CAT SC presents similar hearing damage risk potential to the shooter on a semiautomatic pistol, in the free field, regardless if it is used in the “long” or “short” configuration. The average Suppression Rating at the shooter’s ear, is similar.
PEW Science Research Note 15: It may be important to read the above paragraph, again. The Suppression Rating at the shooter’s ear, on a centerfire pistol, when you change a silencer from its “long” configuration to its “short” configuration, may not appreciably change. This is an extremely important concept to understand. This does not mean that the overall signature of the weapon system is identical. It means that the hearing damage risk to the shooter is almost identical, in the free field.
It is very important to note that what you, as a human, hear is a function of every pressure source propagating through the atmosphere that reaches your pressure sensors (your ears). In early time, the risk to your ear is highest. In late time, after the primary combustion events have vented, there are signature components that may propagate downrange, adjacent to your location, and even back toward you upon reflecting from objects such as tree lines, automobiles, or structures. Those late time signature components can give a subjective impression to the operator that may induce a perception of “loudness.” Loudness, as defined in the Silencer Sound Standard however, is objective hearing damage risk potential.
Factors that may increase the actual objective loudness (the risk to you, the operator) of using a system with a lower muzzle Suppression Rating despite the same or higher shooter’s ear Suppression Rating include shooting the suppressed weapon system:
Indoors.
In a vehicle.
Next to a building, berm, or treeline.
This is the same phenomenon that presents when shooting a high flow rate centerfire rifle silencer on a reciprocating semiautomatic or automatic rifle. Reference the test report of the HUXWRX FLOW 556K (6.83) and FLOW 762 Ti (6.114). Even if not indoors or adjacent to reflecting surfaces, late time signatures propagated from lower muzzle suppression rating systems will influence shooter perception in late time. This does not influence the shooter’s ear Suppression Rating because it does not increase the hearing damage risk potential to the shooter in the free field.
The following section presents overall comparisons on the HK P30L semiautomatic pistol.
6.162.3 Suppression Rating Comparison (Subsonic 9x19mm from the HK P30L)
Figure 9 presents a comparison of the PEW Science Suppression Ratings of the CAT SC in both its long and short configurations with other silencers on the full-size HK P30L semiautomatic pistol using subsonic Speer Lawman 147gr 9mm ammunition.
Figure 9. Suppression Rating Comparisons of the CAT SC in both long and short configurations with the SilencerCo Omega 9K, AAC Ti-RANT 9 Series, the HUXWRX CA$H 9K, Resilient Suppressors RSP, Rugged Obsidian 45, CGS MOD9 FS, and SWR Trident-9 on the HK P30L, Using PEW-SOFT 9x19mm Subsonic Test Data and PEW Science Analysis
In its 7.5-in long configuration, the CAT SC provides balanced performance on a semiautomatic 9mm pistol with the notable benefit of extremely high suppression potential. The level of protection experienced by both operators and bystanders from the CAT SC on this host is both significant and unprecedented. As previously discussed, the gross muzzle suppression performance of the CAT SC in the long configuration, in the free field, is astoundingly high. The silencer in its long configuration is 7.5 inches long. Its muzzle Suppression Rating is 64.3. This performance is almost a full category higher than that of the CGS MOD 9 FS (6.6), which is an extremely high performance pistol silencer with significant back pressure, possessing a muzzle Suppression Rating of 55.2. Even the most refined and mature iteration of the AAC Ti-RANT 9; the Ti-RANT 9M-HD in its long configuration (6.118), is far outclassed by the CAT SC, achieving a muzzle Suppression Rating of 54.4. The level of pure suppression performance differential is nontrivial.
The Suppression Rating at the system operator’s head, in the free field, with the long configuration of the CAT SC is an unprecedented 49.1. This level of operator protection, in the free field, with the full (long configuration) of a high performance silencer is highly unusual. For context, examples of silencers with low backpressure, intended to maximize shooter protection in the free field, include models such as the HUXWRX CASH 9K (6.96), the Resilient Suppressors RSP (6.87), and adjacently, the Inert Haze Ti-P (6.145). These three silencers achieve operator Suppression Ratings in the free field ranging from 42.3 to 45.1. And, their muzzle Suppression Ratings suffer due to higher distal flow rate. The long configuration of the CAT SC achieves an operator Suppression Rating in the free field of 49.1; almost half a category higher than the nearest competitor, with an aforementioned muzzle Suppression Rating that is significantly higher.
The muzzle Suppression Rating of the CAT SC, in the free field, changes from 64.3 to 41.9 when changing from its long to short configuration. The short configuration of the SC is 5.5 inches long, and this performance differential is somewhat expected. Somewhat unexpected is the differential between this performance and larger systems, such as the aforementioned Resilient Suppressors RSP, and the short configurations of all of the other silencers tested in the pedigree. For example, the short configuration(s) of the modular AAC Ti-RANT variants are all almost half an inch longer than the short configuration of the CAT SC. And, all of these silencers have lower early-time flow rates than the CAT SC. The net result, using the CAT SB-SHOCK technology, is an again superior suppressed free field signature severity with the added benefit of further reduced operator hazard.
The short configuration of the CAT SC is approximately half an inch longer than the SilencerCo Omega 9K (6.153). However, the level of protection to the operator with the CAT SC is significantly higher than that of the Omega 9K. This is despite their muzzle Suppression Ratings being closer on this platform. The SilencerCo Omega 9K has significantly higher back pressure. The long configuration of the CAT SC is approximately an inch shorter than the Rugged Obsidian 45 (6.7) and exhibits significantly higher performance.
The shooter’s ear Suppression Ratings of the CAT SC, in its long and short configurations, are similar. As discussed in the full member version of this report, this does not mean that the overall signature of the weapon system is identical. It means that the hearing damage risk to the shooter is almost identical, in the free field. Environmental changes and deviations from free field conditions can, and most likely will, result in protection differentials that shift. Severe environmental differentials may provide severity with highly nonlinear characteristics and outcomes. PEW Science highly encourages examination of the full member version of this report for elaboration on these performance facts.
PEW Science Research Note 15: Because the PEW Science Suppression Rating is a damage risk criterion (DRC), a lower Suppression Rating indicates a higher personnel hazard in the free field. Therefore, silencers with a lower Suppression Rating are postulated to be more hazardous to the unprotected ear than silencers like the CAT SC. To iterate, the Suppression Rating is a DRC - it is not a subjective quantity; it is an objective quantification of hearing damage risk potential.
The signature to which the shooter’s ear is subjected is a function of both ejection port and muzzle signature. When the silencer’s endcap is in closer proximity to the shooter, the severity is increased. The coalescing of the ejection port overpressure with the primary muzzle blast exacerbates the severity of the signature at the shooter’s head position. It is not ejection port signature, alone, that dictates the signature measured at the shooter’s head position.
6.162.4 Review Summary: Combat Application Technologies CAT/SC/B1 on the HK P30L Full-Size Semiautomatic Pistol
When paired with the HK P30L full-size semiautomatic pistol and fired with Speer Lawman 147gr ammunition in its long configuration, the CAT/SC/B1 achieved a Suppression Rating™ of 64.6 in PEW Science testing. In its short configuration with the same host weapon and the same ammunition, the CAT/SC/B1 achieved a Suppression Rating of 50.7.
As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.
PEW Science Laboratory Staff Opinion:
The CAT/SC/B1 (CAT SC) is a lightweight, highly advanced, and modular centerfire pistol silencer that exhibits extreme sound signature suppression performance for both operators and bystanders. The silencer’s combined performance, flow rate, and modularity, represent the most significant advancement in centerfire 9mm pistol suppression in recent history. The CAT SB-SHOCK technology, adapting characteristics from both SURGE BYPASS and DiVerge, results in maximizing performance in relatively small design envelopes; a significant benefit in suppressed handgun applications.
The CAT SC represents a significant departure from common centerfire pistol technology. There are several design features of the SC specifically intended to maximize the holistic signature suppression performance on a 9mm reciprocating handgun system. The HK P30L standard 9x19mm semiautomatic pistol test host, like many common reciprocating centerfire handguns, possesses a locking tilting-barrel action. It is on these systems that the performance of the CAT SC is intended to excel. The long configuration of the CAT SC demonstrates several unusual characteristics that indicate the silencer is operating differently than traditional pistol silencers. A highly unusual attribute to note is that the CAT SC accomplishes high suppression performance with the addition of a significantly high early time flow rate and reduced net backpressure. This type of behavior is truly unprecedented in PEW Science laboratory testing on this host. These combined performance attributes are possible due to the combined technologies implemented in the CAT SC; its design uses CAT SB-SHOCK technology; a specific adaptation combining elements of SURGE BYPASS with DiVerge technologies for centerfire handgun use.
In its 7.5-in long configuration, the CAT SC provides balanced performance on a semiautomatic 9mm pistol with the notable benefit of extremely high suppression potential. The level of protection experienced by both operators and bystanders from the CAT SC on this host is significant. The gross muzzle suppression performance of the CAT SC in the long configuration, in the free field, is astoundingly high. The silencer in its long configuration is 7.5 inches long and exhibits performance almost a full Suppression Rating category higher than that of the CGS MOD 9 FS, which is an extremely high performance pistol silencer with significant back pressure. Even the most refined and mature iteration of the AAC Ti-RANT 9, the Ti-RANT 9M-HD in its long configuration, is far outclassed by the CAT SC. The level of pure suppression performance differential is nontrivial.
The muzzle Suppression Rating of the CAT SC, in the free field, is lower when changing from its long to short configuration. The short configuration of the SC is 5.5 inches long, and this performance differential is somewhat expected. Somewhat unexpected is the differential between this performance and larger systems, such as the Resilient Suppressors RSP, and the short configurations of all of the other silencers tested in the pedigree. For example, the short configuration(s) of the modular AAC Ti-RANT variants are all almost half an inch longer than the short configuration of the CAT SC. And, all of these silencers have lower early-time flow rates than the CAT SC. The net result, using the CAT SB-SHOCK technology, is an again superior suppressed free field signature severity with the added benefit of further reduced operator hazard.
The Suppression Rating at the shooter’s ear, on a centerfire pistol, when you change a silencer from the “long” configuration to the “short” configuration, may not appreciably change, in general. This is an extremely important concept to understand. This does not mean that the overall signature of the weapon system is identical. It means that the hearing damage risk to the shooter is almost identical, in the free field. The PEW Science Member version of this review contains further discussion of this phenomenon.
The CAT SC may be used with CGS and SilencerCo pistons. PEW Science has only evaluated the CAT SC with the CGS 13.5x1mm LH piston on the HK P30L host weapon system. The CAT SC end cap and rear cap may be removed with a wrench by the user; wrench flats are present on both components. The distal section of the silencer may be removed and installed into the primary proximal section by hand. No tools are needed for this disassembly; a tapered interface facilitates rotational retention with hand-snug torque values.
The CAT SC is not intended for submachinegun use. Use on such systems, even if demonstrating high suppression performance, may be suboptimal. PEW Science encourages the user to contact the manufacturer for guidance on silencer use case, firing schedule, maintenance, and other ownership guidance.
In this review, the CAT SC performance metrics depend upon suppressing a full-size combat handgun firing a full-power subsonic centerfire pistol cartridge. This type of evaluation provides a potential upper-bound for typical real handgun silencer performance due to the barrel length and action dynamics of the host weapon. PEW Science encourages the reader to carefully consider action dynamics, barrel lengths, and other characteristics in the selection of centerfire pistol silencer hosts.
The hearing damage potential of centerfire pistol use is significant. PEW Science encourages the reader to consider the Suppression Rating when deciding on an appropriate silencer and host weapon combination for their desired use. Note that the presence of nearby reflecting surfaces, as well as ammunition choice, can influence the sound signature to which both the shooter and bystanders are subjected.
