SSS.6.140 - Combat Application Technologies CAT/SR/A1 and the CZ 452 .22 Bolt-Action
/Combat Application Technologies CAT/SR/A1 on a CZ 452 .22 Bolt Action with 16-in Barrel
The CAT/SR/A1 (“SR” in this report) is designed by Combat Application Technologies (CAT). It is a 22 caliber rimfire silencer, intended to suppress cartridges ranging from .22LR to 5.7x28mm. It has a 1.05-inch diameter and is 5.6 inches long, including its external end cap features. The silencer’s integrated mount and core is DMLS (3D-printed) titanium and the removable end cap is aluminum. The silencer may be installed on host weapons threaded 1/2”-28-tpi. In this test, an adapter was used to convert the native host weapon threads from 1/2”-20tpi. The silencer weighs 2.8 ounces, as tested. The CAT/SR/A1 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 for public research 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 data production for this Sound Signature Review white paper was funded in part by PEW Science Project PEW-CAT-059-001-23. Therefore, data pertaining to the CAT/SR/A1 in this Sound Signature Review is published with the express written permission of Combat Application Technologies.
This Sound Signature Review contains single-test results using the CAT SR mounted to the CZ 452 American bolt-action rifle, chambered in .22LR with a 16-inch barrel. CCI Standard Velocity 40gr ammunition was used in the test.
- Section 6.140.1 contains the CAT SR test results and analysis.
- Section 6.140.2 contains Suppression Rating comparisons with selected .22 rimfire silencers in the subsonic ammunition combustion regime.
- Section 6.140.3 contains the review summary and PEW Science laboratory staff technical opinions.
Summary: When paired with the CZ 452 American bolt-action rifle and fired with CCI SV .22 LR ammunition, the CAT/SR/A1 achieved a composite Suppression Rating™ of 96.8 in PEW Science testing.
The subcompact semiautomatic rimfire pistol performance of the CAT/SR/A1 is detailed in Sound Signature Review 6.141, in which it achieved a composite Suppression Rating of 87.6.
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
6.140.1 CAT/SR/A1 Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the CAT SR 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/SR/A1 Sound Metric Summary
6.140.1.1 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 laboratory sound signature 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 laboratory testing; the recognized 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 are shown in Figure 1a. A zoomed-in timescale displays the region of peak sound pressure in Figure 1b, for the first three shots. The real sound impulse (momentum transfer potential) histories from the same 5-shot test are shown in Figure 2. Again, full and short timescales are shown.
Fig 1a. CAT/SR/A1 Subsonic .22 LR Bolt Action Muzzle Sound Pressure Signature
Fig 1b. CAT/SR/A1 Subsonic .22 LR Bolt Action Muzzle Sound Pressure Signature, Short Time Window
Figure 2a. CAT/SR/A1 Subsonic .22 LR Bolt Action Muzzle Sound Impulse Signature
Figure 2b. CAT/SR/A1 Subsonic .22 LR Bolt Action Muzzle Sound Impulse Signature
The Combat Application Technologies CAT/SR/A1 is a rimfire silencer that exhibits enhanced performance characteristics and incorporates elements of CAT SURGE BYPASS technology in its design. The following performance attributes of note are observed in the above test data:
Low overall pressure signature amplitude is exhibited, with low blowdown duration, to a higher degree than typical (Figure 1).
Precursor flow presents as nominal, with the entire pressure amplitude regime confined to a range less than 120 dB, regardless of phase, which is highly atypical. The time regime of blowdown is also compressed.
First-round-pop (FRP) is not apparent. Slight elevation of the primary pressure wave terminating into rarefaction at 30 ms is noted (Fig 1b) with gas momentum not expressing ancillary combustion externally (Figure 2). The CAT SR nullifies FRP completely on this platform.
PEW Science Research Note 1: PEW Science previously evaluated the CAT SURGE BYPASS technology in several ammunition combustion regimes, including:
Supersonic 5.56x45mm NATO, with multiple barrel length semiautomatic rifles: CAT ODB 10.3-in MK18 (6.120), CAT WB 10.3-in MK18 (6.129), and CAT WB 14.5-in M4A1 (6.130).
Subsonic 300 BLK: CAT ODB 8-in bolt-action (6.122).
In the above evaluations, similar performance attributes were noted with this hybrid technology, regardless of combustion amplitude and duration. When applying the SURGE BYPASS hybrid technology to rimfire applications, high early time flow rate with late time gas momentum throttling remain the principal performance considerations. This differs from technologies such as Flow-Through from HUXWRX or Forward Flux from Sig Sauer, in which late time gas momentum may be higher than desirable if overall sound field suppression is a performance consideration. Research Supplement 6.124 examining the characteristics of different examples of silencer technologies, including hybrid designs, is available for reference.
The performance of the CAT/SR in a higher pressure semiautomatic application is evaluated with the Beretta 21A in article 6.141.
PEW Science Research Note 2: The CAT SR is extremely light weight. The test specimen evaluated by PEW Science weighs approximately 2.8 ounces. In addition to influencing system handling characteristics, the low mass of the silencer also influences the sound signature, directly, by changing the natural frequency of the primary vibrational mode of the total weapon system such that impulsive noise events from mechanical impact are subject to a lower degree of system damping, and thus higher amplitude resonance. In the subsonic rimfire ammunition combustion regime, with silencers exhibiting the degree of signature suppression of the CAT SR, these types of variations may generally be audible to the user, subject to host selection and operating system. This phenomenon is discussed, with supporting test data, in article 6.141.
As noted above, the CAT SR does not produce FRP on this platform. Bystanders are postulated to experience almost identical signature severity throughout the shot string, with the tested ammunition.
The rimfire silencer performance Rankings are now expanding; the CAT SR joins the Resilient Suppressors Jessie’s Girl (6.125) and the Rugged Oculus in both its configurations (6.1) in the current published dataset. In addition to bolt-action rifle evaluation, all three of these silencers have also been evaluated on the subcompact semiautomatic Beretta 21A rimfire pistol. Additional evaluations in the rimfire ammunition combustion regime by PEW Science are forthcoming. Consult the PEW Science Rankings Section for the complete public testing and analysis library.
PEW Science Research Note 3: Users should note that performance of rimfire silencers on long and short barrels may be significantly different, even with subsonic ammunition, depending on silencer design. The CAT SR is somewhat unique in that its performance remains very high regardless of barrel length. The reader is encouraged to examine article 6.141 for that evaluation.
6.140.1.2 SOUND SIGNATURES AT SHOOTER’S EAR
Real sound pressure histories from the same 5-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 5 shots are shown in Figure 3. The primary sound signature history is shown on the left. A zoomed-in timescale is displayed on the right, in the region of peak sound pressure. The real sound impulse (momentum transfer potential) histories at the ear from the same 5-shot test are shown in Figure 4. Full and short timescales are shown.
Figure 3a. CAT/SR/A1 Subsonic .22 LR Bolt Action Ear Sound Pressure Signature
Figure 3b. CAT/SR/A1 Subsonic .22 LR Bolt Action Ear Sound Pressure Signature, Short Time Window
Figure 4a. CAT/SR/A1 Subsonic .22 LR Bolt Action Ear Sound Impulse Signature
Figure 4b. CAT/SR/A1 Subsonic .22 LR Bolt Action Ear Sound Impulse Signature
The level of signature suppression exhibited by the CAT SR, on this platform, is unusually high. Furthermore, the sound signature to which the shooter is subjected is highly unusual because the entirety of the external combustion propagation amplitude is kept to levels at or below that of the firing mechanism of the system.
PEW Science Research Note 4: The mechanical operation of the trigger and firing assembly, as well as the ignition and deflagration of priming compound in the rimfire case and primary propellant, contribute to an overall externally measured signature, including resonance at high sound-speed through the steel barrel, into the titanium silencer, and produce an overall signature that is generally more severe than the external suppressed muzzle blast through the CAT SR. In summary, the CAT SR, to the shooter on this host weapon, nullifies a significant proportion of the external muzzle blast to the shooter, to the degree that it is producing a sound field that most likely is approaching the limits of platform suppression for a CZ 452 bolt-action rifle with a wooden stock, as tested. Although it is theoretically possible to produce a lower amplitude signature with this host weapon, the practical nature of doing so in the current size envelope is approaching several limits.
The signature from the CAT SR, to the shooter, is measured to be as (or more) consistent than the signature from the firing system of the weapon itself. At these levels of signature suppression, even the mass of the silencer can influence perceptible signature components to the shooter and close bystanders. See Research Note 5, below.
PEW Science Research Note 5: If a user desires a Suppression Rating (at the muzzle or shooter’s ear) that is higher than exhibited by the CAT SR in this test, it may be prudent for the user to explore different host options, such as systems with higher mass or impedance mismatches that may contain firing-pin impact noise to a greater degree. Internal material wave propagation may be changed by layering of various materials in a composite structure in a weapon stock, for example. Reduction in signature in such a manner is outside the scope of this article. However, primary mechanical noise limits are the subject of future PEW Science research. Although the PEW Science Suppression Rating Scale is designed for small arms signature damage risk criterion (DRC) applicability, the extreme ends of the scale may be used to quantify such limits, outside the bounds of DRC applicability. It is extremely important to note that mechanical firing system noise (action noise) may change only by changing the mass of an attached silencer, all other things equal, due to dynamic system resonance. This phenomenon is measurable and explored in article 6.141 with CAT SR on the Beretta 21A.
PEW Science Research Note 6: The signature of a high performance rimfire silencer with subsonic ammunition fired from a bolt-action rifle, at the shooter’s head, is significantly suppressed and may not sound like a “gunshot” to the operator or to bystanders. It is important for operators and bystanders to remain cognizant of the potential hazards of firearm use and the potential lethality of such weapon systems; the operation of such systems, if not in accordance with weapon and silencer manufacturer instructions, may still result in serious injury or death.
6.140.2 Suppression Rating Comparison - Subsonic .22 LR
The CAT/SR/A1 was developed to maximize pure sound signature reduction (PEW Science Suppression Rating) on both low and high pressure rimfire hosts (e.g. bolt-action rifle and semiautomatic pistol). Semiautomatic pistol testing of the CAT SR is provided in article 6.141. Figure 5 shows a performance comparison of rimfire silencer configurations tested on a bolt-action rifle shown in public PEW Science testing, to date. Suppression Ratings are shown for both the shooter and bystanders.
Figure 5. Suppression Rating Comparisons Of Rimfire Silencers Using PEW-SOFT subsonic .22 LR Bolt-Action Test Data
The CAT SR exhibits relatively high performance on this host weapon system. The muzzle Suppression Rating is almost half a category higher than the nearest competitor listed: the long configuration of the Rugged Oculus (6.1). The increase in sound suppression performance, over the already high-performing Rugged Oculus on this host, which has baffles optimized for low pressure flow, is very notable. Suppression Ratings in the 90-zone indicate a significantly suppressed signature. Above 95, the Suppression Rating scale quantifies signatures that may not present as similar to gunshots, to most observers. Caution is recommended by both system operators and bystanders (see Research Note 7, below).
At the shooter’s ear, the signature from the bolt-action rifle suppressed with the CAT SR is also approaching the 90-zone. As discussed in the previous section, mechanical noise and resonance may preclude the Suppression Rating at the shooter’s ear from rising to levels significantly higher than that shown here. Further research is planned. It is extremely important to note that mechanical firing system noise (action noise) may change only by changing the mass of an attached silencer, all other things equal, due to dynamic system resonance. This phenomenon is measurable and explored in article 6.141 with CAT SR on the Beretta 21A.
In totality, the CAT SR produces the least severe sound signature on rimfire host weapon platforms of any rimfire silencer tested by the PEW Science laboratory, to date. As discussed in the first section of this report, the CAT SR also does not produce perceptible FRP on this platform. This performance factor may be of significant importance to some users.
PEW Science Research Note 7: The signature of a high performance rimfire silencer with subsonic ammunition fired from a bolt-action rifle, at the shooter’s head, is significantly suppressed and may not sound like a “gunshot” to the operator or to bystanders. It is important for operators and bystanders to remain cognizant of the potential hazards of firearm use and the potential lethality of such weapon systems; the operation of such systems, if not in accordance with weapon and silencer manufacturer instructions, may still result in unintended serious injury or death. The user is encouraged to be mindful of the degree to which sound signature suppression, and resulting personnel hazards, can vary across designs. Small arm weapon system suppression performance is a spectrum. The PEW Science Suppression Rating and the Silencer Sound Standard help quantify this spectrum for end users and industry, objectively.
6.140.3 Review Summary: CAT/SR/A1 on a CZ 452 .22 Bolt Action with 16-in Barrel
When paired with the CZ 452 American bolt-action rifle and fired with CCI SV .22 LR ammunition, the CAT/SR/A1 achieved a composite Suppression Rating™ of 96.8 in PEW Science testing.
The subcompact semiautomatic rimfire pistol performance of the CAT/SR/A1 is detailed in Sound Signature Review 6.141, in which it achieved a composite Suppression Rating of 87.6.
As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.
PEW Science Laboratory Staff Opinion:
The Combat Application Technologies CAT/SR/A1 is a rimfire silencer that exhibits enhanced performance characteristics on a variety of rimfire host weapons of varied barrel length, including bolt action rifles with subsonic ammunition. It is rated for 5.7x28mm, and weighs only 2.8 ounces, as tested. The silencer exhibits no discernable first round pop in the tested combustion regime. Other than the removable end cap, the silencer is sealed; its monolithic DMLS titanium body may be cleaned with a variety of chemical solutions, including those offered by CAT.
The CAT SR incorporates elements of CAT Surge Bypass technology in its design. When applying Surge Bypass hybrid technology to rimfire applications, high early time flow rate with late time gas momentum throttling remain the principal performance considerations. This differs from technologies such as Flow-Through from HUXWRX or Forward Flux from Sig Sauer, in which late time gas momentum may be higher than desirable if overall sound field suppression is a performance consideration.
The CAT SR is extremely light weight. The test specimen evaluated by PEW Science weighs approximately 2.8 ounces. In addition to influencing system handling characteristics, the low mass of the silencer also influences the sound signature, directly, by changing the natural frequency of the primary vibrational mode of the total weapon system such that impulsive noise events from mechanical impact are subject to a lower degree of system damping. For example, pistol action noise from slide closing may sound different to the user with such a silencer installed on the weapon, compared with that from the use of a heavier silencer.
In totality, the CAT SR produces the least severe sound signature on rimfire host weapon platforms of any rimfire silencer tested by the PEW Science laboratory, to date. Its lack of perceptible FRP on this platform may be of significant importance to some users.
Servicing the CAT SR is accomplished by removing the silencer’s end cap and soaking with the user’s choice of cleaning solution to remove lead fouling. The user may choose to use the organic acid CAT 206 cleaning solution, formulated for titanium or Inconel parts. In general, the user is encouraged to contact the manufacturer for cleaning and servicing directives.
PEW Science has not evaluated the durability of the CAT/SR/A1, nor its performance on cartridges other than subsonic .22 LR. It is important for the user to contact the manufacturer to determine the suitability of firing schedules and use cases.
In this review, the CAT/SR/A1 performance metrics depend upon suppressing a subsonic rimfire cartridge on a bolt-action rifle. While the sound signature of such systems can be suppressed to levels that may not sound like a “gunshot” to the operator or to bystanders, PEW Science encourages the reader to remain vigilant with regard to all subsonic rimfire cartridge suppression claims. It is important for operators and bystanders to remain cognizant of the potential hazards of firearm use and the potential lethality of such weapon systems; the operation of such systems, if not in accordance with weapon and silencer manufacturer instructions, may still result in serious injury or death.
The hazard potential of subsonic rimfire rifle use is not insignificant. PEW Science encourages the reader to consider the Suppression Rating when deciding on an appropriate silencer and host weapon combination for their desired use.
