SSS.6.159 - Combat Application Technologies CAT/DD/A1 and the Savage Model 10 PC .308 (Free Version)

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Combat Application Technologies CAT/DD/A1 on a Savage Model 10 .308 with 20-in Barrel

The CAT/DD/A1 (“Dirty Dave,” or “DD” in this report) is designed by Combat Application Technologies (CAT). It is a compact “K”-sized 30 caliber centerfire rifle silencer, intended to suppress the 7.62x51mm NATO M80 cartridge from short barrels on reciprocating weapons. It has a 1.6-inch diameter and the silencer core is 5.4 inches long (HUB model) or 5.8 inches long (QD model). The HUB compatible model features 1.375”-24 tpi threading allowing for the installation of a variety of 3rd-party mounting systems and muzzle devices with the silencer. Length of the total system will vary, depending on mount choice. For example, use of the CAT/TSF X, a threaded coupler, will result in the HUB version’s total system length equaling that of the QD version of the silencer. The entirety of the silencer is DMLS (3D-printed) from a proprietary Inconel alloy. The limited production titanium versions of the silencer weigh 8.4 ounces and 9.2 ounces (HUB and QD cores, respectively).  The core of the tested Inconel QD silencer model weighs 18.4 ounces. The Spooky1/A2 flash hider used in testing of the QD model resulted in a total system weight of 21.1 ounces and total system length of 6 inches.  The CAT DD 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/DD/A1 in this Sound Signature Review is published with the express written permission of Combat Application Technologies.

This review contains single test results using the CAT DD with a Spooky1/A2 flash hider mount on the Savage Model 10 Precision Carbine rifle, chambered in .308WIN with a 20-inch barrel. Federal XM80 149gr ammunition was used in the test.

  • Section 6.159.1 contains the CAT DD test results and analysis.

  • Section 6.159.2 contains back pressure and Suppression Rating comparisons with selected .30 rifle silencers possessing a PEW Science Back Pressure Metric, Ω [Pa-1] in Omega Zone 4 and below. An updated Ω metric chart for the full suite of publicly evaluated .30 rifle silencers is also provided in this section. Further information about the Ω metric and Omega Zones can be obtained in PEW Science Research Supplement 6.40 (Public Article).
  • Section 6.159.3 contains the review summary and PEW Science laboratory staff technical opinions.

Summary: When paired with the Savage M10 20” .308 and fired with Federal XM80, the CAT/DD/A1 with a Spooky1/A2 flash hider mount achieved a Suppression Rating™ of 32.6 in PEW Science testing.

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

6.159.1 CAT/DD/A1 Sound Signature Test Results

A summary of the principal Silencer Sound Standard performance metrics of the CAT DD is shown in Table 1. The data acquired 1.0 m (39.4 in) left of the muzzle is available for viewing to all. The data acquired 0.15 m (6 in) right of the shooter’s ear is only available to membership supporters of PEW Science and the Silencer Sound Standard. You can support public PEW Science testing, research, and development with a membership, here. State-of-the-art public firearm sound signature testing and research conducted by PEW Science is supported by readers like you.

 

Table 1. CAT/DD/A1 Sound Metric Summary

 

6.159.1.1 SOUND SIGNATURES AT THE MUZZLE

Real sound pressure histories 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 5 shots with the CAT DD 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 5-shot test are shown in Figure 2a. In Figure 2b, a shorter timescale is shown comparing the impulse of the first three shots.

Fig 1a. CAT/DD/A1 Bolt Action Rifle Muzzle Sound Pressure Signature

Fig 1b. CAT/DD/A1 Bolt Action Rifle Muzzle Sound Pressure Signature, Short Time Window

Figure 2a. CAT/DD/A1 Bolt Action Rifle Muzzle Sound Impulse Signature

Figure 2b. CAT/DD/A1 Bolt Action Rifle Muzzle Sound Impulse Signature, Short Time Window

Figure 1b shows a 1.8 millisecond long portion of the free field pressure signatures of the first two rounds fired from the CAT DD, as measured 1.0 m left of the muzzle. There are several significant waveform features labeled:

  1. The end cap exit event, consisting of bullet shock and the initial jet, results in a peak overpressure magnitude of 151.7 dB during the first shot.

  2. The coupled jet during the second shot reaches a peak amplitude of 150.8 dB.

  3. Initial first-round-pop (FRP) jetting divergence occurs early, but normalizes expediently.

  4. Initial flow is characterized by a relatively long positive phase duration immediately followed by lower amplitude jetting.

This is a somewhat typical sequence observed when firing supersonic .308WIN ammunition from a bolt-action rifle with an attached silencer that exhibits relatively low flow restriction (low back pressure). Internal silencer design can significantly influence the measured timing and pressure amplitudes. Preliminary back pressure comparisons are shown in Section 6.159.3 of this review, with the PEW Science Back Pressure Metric, Ω [Pa-1]. Note that weapon system influence is a function of both Ω and early-time wave propagation factors which may be measured inside the system, in close proximity to the muzzle orifice. These factors include the PEW Science alpha parameter; a subject of internal research.

PEW Science Research Note 1: In addition to the labeled waveform features noted above, the CAT DD exhibits significantly reduced blowdown time, as shown in Figure 1a, prior to ground reflection at approximately 36.3 ms.  This blowdown rate is relatively unusual for a silencer exhibiting a Muzzle Suppression Rating of almost 23 on this platform.  Typically, silencers achieving such sound field severity adjacent to the distal end of the system restrict blast momentum transfer for a longer duration.  Another unusual characteristic observed in the test data of the CAT DD is the extremely rapid rise to maximum peak positive phase impulse (Figure 2), placing the silencer in Omega Zone 1.  Silencers in Zone 1 are typically characterized with much more severe signatures, such as the Dead Air Sandman-K (6.15), and the short configuration of the Rugged Radiant (6.12).  It is typically not until momentum transfer rate is reduced to enter Zone 2 that signature severity is significantly reduced.  And, even then, “K” silencers in that zone such as the Surefire SOCOM762-MINI2 (6.106) restrict flow to a greater degree, yet produce a more severe signature on this 7.62x51mm NATO platform.  The Combat Application Technologies DD is able to produce gross signature severity in the free field that is more similar to larger conventional silencers like the Dead Air Sandman-S (6.11), while possessing gross momentum transfer potential similar to efficient and larger high flow rate silencers such as the HUXWRX (OSS) HX-QD 762 (6.41).

PEW Science Research Note 2: To achieve the combination of performance traits noted above, the CAT DD utilizes a variant of CAT SURGE BYPASS technology used in the CAT ODB (6.120) adapted for the short “K” length. Technology adaptations in the two models differ due to design use-case(s); the ODB is designed for intermediate rifle cartridges in multiple velocity regimes, and the DD is designed for M80 NATO specified ammunition on reciprocating weapon systems. The technology in the two silencers is much different than CAT SNIPER2 technology, which also possesses a high early-time flow rate, with a late time flow rate throttled to control blast momentum propagation for bolt-action systems.

It is important to note the differences between SURGE BYPASS technology used in some CAT silencers and Flow-Through technology used in the different generations of OSS and HUXWRX silencers. Flow-Through silencers are intended to maximize both gas velocity and internal flow path length, whereas hybrid technologies such as SURGE BYPASS, and others, are adapted to exhibit differing distal flow rates as a function of input pressure and duration. In the CAT DD K-size adaptation of SURGE BYPASS, a partial convergence of the two design philosophies is observed. This is due to the short system envelope and the high-pressure design intent of the DD. Users are encouraged to examine the differences in flow rate in different time regimes when selecting rifle silencers appropriate for their systems.

PEW Science Research Note 3: Again, the behavior of the CAT DD described above is unusual, particularly because of the silencer’s design envelope.  The core of the silencer is 5.4 inches long, and in the tested configuration is 6 inches long.  The CAT DD is almost half an inch shorter than the SOCOM762-MINI2, less than an ounce heavier, possesses a much higher flow rate, and provides significantly higher suppression performance.  Contextually, this is notable.  Another notable characteristic of its performance on the tested system is the consistency of blast load momentum propagation, as well as the way the FRP accumulation manifests. Like many silencers possessing a high distal flow rate, the CAT DD produces an initially high momentum transfer rate (noted at approximately 29.75 ms, Fig. 2b).  However, upon further accumulation, the DD is shown to maintain the rate measured in subsequent shots; its FRP momentum transfer differential is effectively nullified.  While low relative FRP severity is often common in high flow rate silencers, it is relatively uncommon in short silencers of this performance class.

PEW Science Research Note 4: There does exist a silencer in the research pedigree that is similar in size to the CAT DD that eclipses it in gross sound suppression performance on this host weapon: the Liberty Precision Machine Anthem-K (6.80). While the Anthem-K does possess overall higher suppression performance, the free field severity adjacent to the weapon system is greater than that of the CAT DD, as reflected in the muzzle Suppression Rating differential. The FRP severity of the Anthem-K is also higher (both in relative and absolute comparison). Furthermore, its flow rate is lower than the DD, highlighting the different design intents of the silencers; the CAT DD more purposely adapted to use on reciprocating systems. Testing and analysis of rifle silencers on reciprocating 7.62x51mm NATO platforms is the subject of future PEW Science research.

The performance comparison of advanced silencers like the Anthem-K and the DD highlight the nuance of which users may not be aware if only gross Composite Suppression Rating comparisons are used, especially when use case becomes a consideration. For example, while the Anthem-K may be less appropriate for use on reciprocating systems than the DD for some users, the use of subsonic 300 BLK ammunition with the Anthem-K could potentially provide superior performance to that of the DD, due to the design of the two systems. Silencer performance is a spectrum and a function of particular technology; not every silencer is appropriate for use on every platform, despite similar bore size.

Again, consistent with the above measured pressure and impulse waveform features, the computed PEW Science Omega Metric is relatively low, placing the silencer in Omega Zone 1. Relative Suppression Rating and flow restriction (back pressure) data is presented in Section 6.159.2 of this review.

As typically indicated, first-round sound signatures always differ from subsequent shots, as the atmosphere within the silencer changes. The FRP phenomenon cannot always be shown by viewing only the peak sound pressure. This is one of the reasons why The Silencer Sound Standard requires examining multiple sound signature metrics. Ammunition consistency can play a role in the determination of FRP, however, the close examination of measured pressure and impulse waveforms typically excludes ammunition from the possible factors influencing true FRP, due to the relative consistency of most high quality factory ammunition.

PEW Science has made a concerted effort to characterize the FRP phenomenon with true physiological human inner-ear response analyses. Additional PEW Science Member Research Supplements containing this information are released periodically.  Shooter’s ear hazard analysis and phenomenology examination is provided in the Member Version of this report.

6.159.2 Relative Suppression Rating and Back Pressure Comparisons (.30 Rifle Silencers)

The CAT DD suppressor is intended to offer competitive sound signature suppression throughout the pressure field on reciprocating 7.62x51mm NATO host weapons, with a high flow rate, in a compact envelope. PEW Science has developed an empirical relation to quantify the back pressure (flow restriction) of silencers. Figure 5 and Figure 6 show supersonic suppression and back pressure comparisons between selected 7.62mm (30 caliber) rifle silencers shown in public PEW Science Sound Signature Reviews, as of the date of this review publication. The results shown in Figure 5 and Figure 6 are calculated from real test data acquired with PEW-SOFT. Please note the following:

  1. The PEW Science Back Pressure Metric, Ω [Pa-1], may be generated for any silencer and suppressed weapon system using any suitable raw external overpressure signature data acquired 1.0 m left of the silencer end cap. PEW Science highly recommends data acquisition in accordance with The Silencer Sound Standard.

  2. Omega Zones are presented in Table 3, below, which are intended to provide guidance to weapons developers, silencer designers, and end-users, with regard to flow restriction characteristics of different silencer designs. It is very important to note that silencers possessing a relatively high Ω can still provide functional use on weapon systems. Some weapon systems are more sensitive to Ω than others.

  3. It is important to note that a silencer’s Omega Zone can shift when using a mounting scheme that differs from that used in the testing referenced in the published PEW Science Sound Signature Reviews. This phenomenon occurs due to some silencer mounting schemes significantly influencing flow restriction with some silencer designs.

  4. The theoretical lower limit of flow restriction, or so-called "zero back pressure" would be represented by the unsupressed state, Ω = 0 [Pa-1].

  5. PEW Science acknowledges that other dynamic events occur within a suppressed weapon system that can also influence weapon function. Therefore, PEW Science acknowledges that Ω is not the sole parameter one must consider for total supppressed weapon system operation. However, PEW Science postulates that the Ω metric influence can be significant. Note that weapon system influence is also a function of early-time wave propagation factors which may be measured inside the system, in close proximity to the muzzle orifice. These factors include the PEW Science Alpha parameter; a subject of internal research.

  6. The Back Pressure Metric relations are most easily viewed on a logarithmic scale (See Figure 6).

Figure 5. Omega Back Pressure Metric And Suppression Rating Comparisons Of .308 Rifle Silencers Using PEW-SOFT Data and Analysis

As stated above, the PEW Science Back Pressure Metric is most easily viewed on a logarithmic scale. The metric is nonlinear; the shape of the trend in the data presented in Figure 6, below, illustrates the potential thresholds of extreme flow rate (approaching the unsuppressed state) and extreme flow restriction (approaching the trapping of the maximum amount of combustion byproducts in a system).

Figure 6. Omega Back Pressure Metric Comparisons Of .308 Rifle Silencers Using PEW-SOFT Data and Analysis

Omega characterizes silencer back pressure. It is important to note that back pressure is not blow back. The back pressure of a silencer is the flow restriction it introduces in a suppressed weapon system. The blow back phenomenon that can occur during the use of a suppressed weapon system is caused by the reciprocating system actuating too early relative to overpressure decay within the weapon system, resulting in exposure of excessive internal system overpressure to atmosphere. Some weapons may be tuned to function well with silencers in a high Omega Zone. Some weapons may require low-Omega silencers due to constraints in their operating system(s). Omega metric technical details can be found in PEW Science Public Research Supplement 6.40.

Table 3. PEW Science Back Pressure Metric Omega Zones And Suppressed Weapon System Functional Descriptions

As stated above, weapon system influence is a function of both Ω and early-time wave propagation factors which may be measured inside the system, in close proximity to the muzzle orifice. These factors include the so-called PEW Science Alpha parameter; a subject of internal research.  The CAT DD was tested with a flash hider mount which most likely does not significantly influence early time shock reflections near the muzzle, but more testing is needed to determine this influence.  Mount geometry, chamber geometry, and the blast baffle shape all contribute to early-time flow restriction, in addition to late-time flow restriction characterized by Omega. 

As discussed in Section 6.159.1.1 of this report and reflected in Figure 5, the performance of the CAT DD on this weapon system significantly exceeds that of other silencers in the same Omega Zone, as well as some other silencers that exhibit higher flow restriction. Short silencers with extremely high distal flow rates (but not high early time flow rates) such as the Dead Air Sandman-K (6.15), and the short configuration of the Rugged Radiant (6.12) induce much more severe hearing damage risk to the weapon operator and bystanders. And, again, as distal flow rate is reduced, even hybrid-design “K” silencers like Surefire SOCOM762-MINI2 (6.106) induce more personnel risk than the CAT DD. It is not until either system length is increased, or distal flow rate significantly decreased, that performance increases are seen; the HUXWRX (OSS) HX-QD 762 (6.41) an example of the former, and the Liberty Precision Machine Anthem-K (6.80) an example of the later.

PEW Science Research Note 7: There are other silencers the same length as the CAT DD that possess more restrictive flow and still produce more severe hazards. For example, the Energetic Armament VOX-S (6.3) is almost the same size, as tested. Both silencers are intended for use on reciprocating systems with high durability. The technologies in the silencers are drastically different. Other 30-caliber rifle silencers that produce similar gross sound field severity to the CAT DD on this weapon system are longer, and again, exhibit much lower flow rates. Examples of such silencers include the Dead Air Sandman-S (6.11), the short configuration of the Rugged Surge (6.22), and the long configuration of the previously mentioned Rugged Radiant. Interestingly, the Q Trash Panda (6.4) is both longer and larger in diameter than the CAT DD, yet exhibits a more severe muzzle Suppression Rating with significantly reduced early time flow rate due to the adverse blast wave reflections induced by the Q Cherry Bomb muzzle device.

PEW Science Research Note 8: Contextually for the intended silencer use case, it is expected that muzzle Suppression Rating on this host weapon may be relevant for users of the CAT DD, as ejection port signature on reciprocating weapon systems will modify the pressure field displayed in this test report. Accordingly, it is postulated that silencers like the CGS Hyperion K (6.28) and the 3-Prong mounted Surefire SOCOM762-RC2 (6.26) may present as comparable to the CAT DD, to observers in the near to mid-field, with the caveat that reciprocating weapon system tuning creates ejection port blast differentials that can skew field shape and severity for both the operator and bystanders. High-level estimates based on PEW Science laboratory test data and field trials indicate SOCOM762-MINI2 ejection port blast phenomenology, combined with SOCOM762-RC2 distal performance to be an approximate analog for CAT DD semiautomatic 7.62x51mm NATO performance. Further testing is needed to evaluate this hypothesis. Interestingly, the larger CGS Helios QD (6.13) with its vented end cap induces a much more severe overall pressure field than the CAT DD, and has more flow restriction in both early and late time. This is a further example of the design intent of different technologies resulting in performance differentials on a single platform.

There are many silencers evaluated in the 7.62x51mm NATO combustion regime in the research pedigree, and the reader is encouraged to view the PEW Science Rankings Section of the Standard for comprehensive comparison. For length and weight filters to view the dataset with more context, use of the Member Suppression Rating Visualization Tool at the bottom of that page is encouraged.

PEW Science urges the reader not to misconstrue a low Omega metric with the mirroring of unsuppressed weapon function, nor a high Omega Metric with absolute use prohibition on semi-automatic systems. Each weapon system may experience varying sensitivity to different Omega Zones and users may exhibit varying preference for weapon system function and operability. The Zones are provided by PEW Science to assist the reader with determination of postulated applicability of silencer types, as some users may only have experience with certain silencers. The Omega Metric is one performance indicator; it allows overall flow rate phenomena to be categorized independently from sound signature suppression performance. Note that weapon system influence is also a function of early-time wave propagation factors which may be measured inside the system, in close proximity to the muzzle orifice.

It is extremely important to note that peak sound pressure [dB], peak sound impulse [dB-ms], and Omega (Ω) [Pa-1], alone, do not determine the sound supression performance of a silencer. It is the combination of these and other waveform parameters that form the total sound signature and the influence on human inner ear response. The PEW Science Suppression Rating computation considers all of these factors.

6.159.3 Review Summary: Combat Application Technologies CAT/DD/A1 on a Savage Model 10 .308 with 20-in Barrel

When paired with the Savage M10 20” .308 and fired with Federal XM80, the CAT/DD/A1 with a Spooky1/A2 flash hider achieved a Suppression Rating™ of 32.6 in PEW Science testing.

As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.

PEW Science Laboratory Staff Opinion:

The CAT/DD/A1 (CAT “Dirty Dave” or CAT DD) is a compact “K-sized” 7.62x51mm NATO rifle silencer intended for use on reciprocating weapons. The silencer exhibits a high flow rate and significant sound suppression for its size.  Using a high pressure adaptation of CAT SURGE BYPASS technology, the CAT DD produces low relative FRP and is one of the most consistent compact 30-caliber rifle silencers evaluated in the research pedigree in this combustion regime.

The sound field produced by the CAT DD is unusually biased toward muzzle suppression for its high flow rate and size, on high pressure systems. The silencer exhibits significantly reduced blowdown time, which is relatively unusual for a silencer exhibiting a muzzle Suppression Rating of almost 23.  Typically, silencers achieving such sound field severity adjacent to the distal end of the system restrict blast momentum transfer for a longer duration. Short silencers with extremely high distal flow rates (but not high early time flow rates) such as the Dead Air Sandman-K, and the short configuration of the Rugged Radiant, induce much more severe hearing damage risk to the weapon operator and bystanders. As distal flow rate is reduced, even hybrid-design “K” silencers like Surefire SOCOM762-MINI2 induce more personnel risk than the CAT DD. It is not until either system length is increased, or distal flow rate significantly decreased, that performance increases are seen; the HUXWRX (OSS) HX-QD 762 an example of the former, and the Liberty Precision Machine Anthem-K an example of the later.

It is important to note that the CAT DD is purposely-designed for short-barrel 7.62x51mm NATO reciprocating rifles; it is not intended for use with subsonic 300 BLK weapons.  SURGE BYPASS technology adaptations in the CAT DD and the CAT ODB are different; extrapolation of performance in the subsonic ammunition combustion regime between the two silencers is not advised, in accordance with internal PEW Science laboratory testing.

Contextually for the intended silencer use case, it is expected that muzzle Suppression Rating on this host weapon may be relevant for users of the CAT DD, as ejection port signature on reciprocating weapon systems will modify the pressure field displayed in this test report. Accordingly, it is postulated that silencers like the CGS Hyperion K and the 3-Prong mounted Surefire SOCOM762-RC2 may be comparable to the CAT DD, to observers in the near to mid-field, with the caveat that reciprocating weapon system tuning creates ejection port blast differentials that can skew field shape and severity for both the operator and bystanders. High-level estimates based on PEW Science laboratory test data and field trials indicate SOCOM762-MINI2 ejection port blast phenomenology, combined with SOCOM762-RC2 distal performance to be an approximate analog for CAT DD semiautomatic 7.62x51mm NATO performance. Further testing is needed to evaluate this hypothesis. Interestingly, the larger CGS Helios QD with its vented end-cap induces a much more severe overall pressure field than the CAT DD, and has more flow restriction in both early and late time. This is a further example of the design intent of different technologies resulting in performance differentials on a single platform.

The CAT DD evaluated in this test program is constructed from a proprietary Inconel alloy and the silencer was fielded with a closed-tine flash hider.  Although it is unlikely that CAT brake or flash hider use appreciably changes the performance metrics in this report, use of third-party flash hider mounts with open tines may induce system erosion faster than typical due to blast load jet focusing, regardless of silencer material or construction.  This is a general caution for users of all rifle silencers on short-barrel high pressure intermediate rifle cartridge and rifle cartridge systems. A multitude of different silencer mounting systems may be used with the CAT DD due to a universal rear “HUB” mount being offered.  Users should note that limited production titanium versions of the silencer are also available, offering significantly reduced weight with an according decrease in aggressive firing schedule tolerance.

In this review, the CAT/DD/A1 performance metrics depend upon suppressing a supersonic centerfire rifle cartridge; no easy task. PEW Science encourages the reader to remain vigilant with regard to all supersonic centerfire rifle suppression claims. The gas volume and combustion products created by the firing of the supersonic .308WIN cartridge are significant; the measured pressure and impulse magnitudes, and their durations, illustrate this fact.

The hearing damage potential of supersonic centerfire rifle 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.