SSS.6.205 - Combat Application Technologies CAT/BEN and the Beretta 21A
/Combat Application Technologies CAT/BEN on a Beretta 21A Subcompact Semiautomatic Pistol
The CAT/BEN (“BEN” in this report) is designed by Combat Application Technologies (CAT). It is a compact 22 caliber rimfire silencer, intended to suppress cartridges ranging from .22LR to 5.7x28mm. It has a 1.28-inch outer diameter and is 4.28 inches long. The silencer is DMLS (3D-printed) titanium and may be installed on host weapons threaded 1/2”-28-tpi. The silencer weighs 3.8 ounces, as tested. The CAT/BEN can be obtained from Silencer Shop.
Report Table of Contents:
6.205.1 CAT BEN test results and analysis.
6.205.2 Suppression Rating comparisons with selected .22 rimfire silencers in the subsonic ammunition combustion regime.
6.205.3 Report summary and PEW Science laboratory staff technical opinions.
Silencer Hazard Map:
The predicted personnel hazards generated by the tested weapon system in this report, in the free field, are shown in the adjacent Silencer Hazard Map. Click or tap the Map to enlarge. Please reference Silencer Hazard Map Brief 8.1.2 for further details. The PEW-SOFT HD Blast Hazard Prediction Tool and Hazard Mapper is presented in Report 8.1.1.
CAT BEN Beretta 21A .22LR Free Field Hazard Map Produced by PEW-SOFT HD Blast Hazard Prediction Tool using PEW Science Test Data
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 analysis production for this Sound Signature Review was funded in part by PEW Science Project PEW-CAT-059-005-25. Therefore, data pertaining to the CAT/BEN 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 BEN mounted to the Beretta 21A subcompact semiautomatic pistol, chambered in .22LR with a 2.4-inch barrel. CCI Standard Velocity 40gr ammunition was used in the test.
Summary: When paired with the Beretta 21A subcompact semiautomatic pistol and fired with CCI SV .22 LR ammunition, the CAT BEN achieved a composite Suppression Rating™ of 79.6 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
6.205.1 CAT BEN Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the CAT BEN 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 BEN Sound Metric Summary
6.205.1.1 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; the Beretta 21A pistol does not possess a last round bolt hold open feature, and thus the slide does not lock back on the last round fired. Only five shots are considered in the analysis, to maintain consistency with the overall PEW Science public dataset. 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 6 shots are shown in Figure 1a. A zoomed-in timescale displays the region of peak sound pressure in Figure 1b, of the first two shots. The real sound impulse (momentum transfer potential) histories from the same 6-shot test are shown in Figure 2. Again, full and short timescales are shown, this time of Shots 1, 2, and 3.
Fig 1a. CAT BEN Subsonic .22 LR Beretta 21A Subcompact Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 1b. CAT BEN Subsonic .22 LR Beretta 21A Subcompact Semiautomatic Pistol Muzzle Sound Pressure Signature, Short Time Window
Figure 2a. CAT BEN Subsonic .22 LR Beretta 21A Subcompact Semiautomatic Pistol Muzzle Sound Impulse Signature
Figure 2b. CAT BEN Subsonic .22 LR Beretta 21A Subcompact Semiautomatic Pistol Muzzle Sound Impulse Signature
The Combat Application Technologies CAT/BEN is a truncated length larger diameter variant of the CAT/SR/A1 (6.141). Also a hybrid design, the CAT BEN is 24% (over an inch) shorter than the 5.6-in long SR, with a 4.2-in length. The 0.2-in diameter increase allows for this shorter implementation of CAT Surge Bypass to still achieve significant high pressure input (short barrel pistol) suppression performance, albeit not the extreme performance observed in the CAT SR testing.
There are four principle differences between the CAT BEN and the CAT SR in a “worst case” short barrel rimfire pistol suppression application:
First-round-pop (FRP) mitigation; the SR masks FRP, regardless of barrel length. There is FRP from the BEN.
Overall suppression performance, as quantified by the Suppression Rating; the larger SR has superior performance.
The BEN is shorter, larger diameter, and 1 ounce heavier than the SR.
The BEN exhibits less resonance than the SR from mechanical slide closing impact due to (3). Ref. Research Note 1, 6.141.1.1.
The rest of the suppression performance attributes of the CAT BEN, including combustion propagation consistency and back pressure, are similar to that of the CAT SR, due to the application of similar technology. There are no other silencers evaluated by PEW Science, to date, that exhibit the suppression performance of the CAT BEN in the same length envelope, in this combustion regime. Like the short configuration of the Rugged Oculus (6.2), the CAT BEN may be considered a “micro” rimfire silencer.
PEW Science Research Note 1: The FRP signature from the CAT BEN is approximately 50% more severe than subsequent shots, to bystanders in the free field on this weapon system, on average. This determination is a targeted finding, as testing is performed with a short barrel rimfire pistol. FRP signatures on longer barrel host weapons will most certainly be different; most rimfire silencers exhibit minimal FRP when fielded on long barrels. Overall short-barrel CAT BEN suppression performance is characterized by the following observations in the above test data:
Significantly suppressed primary muzzle blast pressure amplitude, post-FRP (Fig. 1a).
Immediate FRP signature divergence in both pressure space (Fig. 1b) and impulse space (Figure 2).
Stepped FRP divergence; the primary FRP blast momentum accumulation results from the immediate short duration blast jet, with continuous propagation throughout most of the primary positive phase duration (Fig. 2b).
Notable post-FRP consistency (Fig. 2b.).
Damped slide-closing signatures when compared to the CAT SR, as highlighted above (Fig. 1a).
PEW Science Research Note 2: Silencer length is the performance parameter compromise with the CAT BEN. With this implementation of Surge Bypass in the subsonic ammunition combustion regime on a short barrel, complete FRP quenching proves challenging in its 4.2-in silencer length. Below 5-in total silencer length, on a 2.4-in rimfire barrel, performance suffers across brands, models, and technologies. For example, the 3.25-in long “short configuration” of the Rugged Oculus (6.2) produces erratic and severe combustion on this weapon system. It is not until a length of 5-in that silencers like the Off Grid Scorpius (6.188) are typically able to quench FRP to a significant degree. Whether or not the FRP quenching silencer length threshold, on the 2.4-in barrel host weapon, will drop below 5-in remains to be seen. Further research is ongoing. While the increased diameter of the CAT BEN does assist with achieving exceptional suppression performance for its length, there are certainly physical limitations tied to length envelope that bear further investigation.
PEW Science Research Note 3: As a subcompact or “micro” rimfire silencer, there are limited datapoints in the Rankings within the public Silencer Sound Standard research pedigree for performance comparison. Nonetheless, some informative comparisons can be made. The pure muzzle suppression performance of the CAT BEN exceeds that of the Rugged Oculus (6.2) in both its long and short configurations, on this host weapon. As the “long configuration” of the Rugged Oculus is 1 inch longer than the CAT BEN, this comparison is significant. The suppression performance of the BEN approaches that of the Resilient Suppressors Jessie’s Girl (6.136) and the Off Grid Scorpius (6.188), but falls short. This is somewhat expected due to the length differentials. The Jessie’s Girl is 5.4 inches long.
PEW Science Research Note 4: The rimfire silencer short-barrel pistol suppression performance Rankings are now expanding; the CAT BEN joins the PWS BDE 22, Off Grid Scorpius, the Otter Creek Labs Titanium, the CAT SR, the Resilient Suppressor’s Jessie’s Girl and the Rugged Oculus (in two configurations) in the current published dataset. Again, 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. These performance differentials are the subject of ongoing PEW Science research.
6.205.1.2 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 shooter’s ear for all 6 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, for Shots 1, 2, and 3. The real sound impulse (momentum transfer potential) histories at the ear from the same 6-shot test are shown in Figure 4. Full and short timescales are shown.
Figure 3a. CAT BEN Subsonic .22 LR Beretta 21A Subcompact Semiautomatic Pistol Ear Sound Pressure Signature
Figure 3b. CAT BEN Subsonic .22 LR Beretta 21A Subcompact Semiautomatic Pistol Ear Sound Pressure Signature, Short Time Window
Figure 4a. CAT BEN Subsonic .22 LR Beretta 21A Subcompact Semiautomatic Pistol Ear Sound Impulse Signature
Figure 4b. CAT BEN Subsonic .22 LR Beretta 21A Subcompact Semiautomatic Pistol Ear Sound Impulse Signature
Much of the same behavior measured at the muzzle of the system is displayed in the waveforms measured at the shooter’s ear with the CAT BEN. The signatures are of significantly low amplitude. This is the case in pressure space (Figure 3) as well as in the examination of the blast impulse signatures (Figure 4). Ejection port blast is minimized.
Note that the FRP impulse differential at the shooter’s ear is not as severe as it is at the muzzle. This is because FRP is a muzzle-blast driven phenomenon and ejection port blast is a dominant blast load source from suppressed semiautomatic host weapons.
PEW Science Research Note 6: The reader may compare Fig. 4a above with that in the CAT SR report. Note that as muzzle blast starts to contribute to the blast loads in this part of the pressure field near the operator’s head, blast momentum accumulation is more severe with the CAT BEN. This stands to reason due to the 4.2 inch length of the BEN trapping less combustion products and placing the muzzle blast source slightly closer to the operator.
PEW Science Research Note 7: The Suppression Rating of the CAT BEN at the shooter’s ear is in the 70 zone on this host weapon. This is significant in context, as the larger PWS BDE 22 has only a marginally higher shooter’s ear Suppression Rating, for example. The BDE 22 is the same length, approximately, as the CAT SR. Technology advancement is significant, even in the rimfire suppression space.
PEW Science Research Note 8: In addition to significantly suppressed muzzle blast loads, the ejection port blast loads being less severe with the BEN hybrid design contribute to the aforementioned high(er) shooter’s ear Suppression Rating for the silencer’s length. The hybrid design of the silencer pays dividends in this regard. The oscillatory momentum displayed post-peak at approximately 32.8 ms (Figure 4) highlights how mechanical action noise, itself, is a large proportion of the overall signature. The blast loads are being suppressed to low amplitudes. Another driver of operator risk is weapon mechanical noise; the slide returning to battery is detailed in Fig. 3b. Note that hazard is cumulative throughout the entire shot event and the entire event history is used to compute the Suppression Rating. The Suppression Rating is a universal damage risk criterion (DRC) metric and may be used to compare any system in the Rankings section of the Standard in free field hazard potential. It is not possible to use peak transient metrics alone, such as those reported in Table 1, to perform this type of hazard comparison. Peak transient metrics alone (peak pressure [dB] and impulse [dB-ms]) are inadequate for DRC applications and use of those types of metrics to predict personnel hazards may produce erroneous and potentially significantly unconservative results.
Further comparison of the CAT BEN rimfire pistol suppression performance is provided below.
6.205.2 Suppression Rating Comparison - Semiautomatic Subsonic .22 LR
The CAT BEN was developed to maximize pure sound signature reduction (PEW Science Suppression Rating) in a short “micro” length envelope. Figure 5 shows a performance comparison of rimfire silencer configurations tested on a subcompact semiautomatic pistol 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 Beretta 21A Subcompact Semiautomatic Pistol Test Data
The performance of the CAT BEN on the short-barrel subcompact semiautomatic rimfire pistol platform is high for its length, at both the muzzle and ear.
The performance gap between the CAT BEN and both configurations of the Rugged Oculus are nontrivial; the long Oculus is over an inch longer than the BEN, whereas the short Oculus is shorter than the BEN. Regardless of configuration, the BEN outperforms the Oculus on this weapon system. The next shortest competitor, the Off Grid Suppressors Scorpius, is a full 5 inches long, and nominally outperforms the 4.2-in long CAT BEN in muzzle suppression and FRP reduction. Free field personnel protection is very similar between the silencers, on average. In general, the use of any of the tested silencers will protect both the operator and personnel adjacent to the muzzle of the weapon system significantly more than when compared to micro-silencer configurations like the short Oculus.
As previously highlighted, full-size rimfire silencers like the Otter Creek Labs Titanium (6.150) and PWS BDE 22 (6.190) will outperform 22 micro silencers. However, in addition to eclipsing the performance of the Oculus, the CAT BEN starts to approach the overall suppression performance of some full size silencers like the Resilient Suppressors Jessie’s Girl (6.136). Performance variation, with length, becomes increasingly relevant as suppression technology advances.
The signature of a high performance rimfire silencer with subsonic ammunition fired from a semiautomatic pistol is significantly suppressed and may not sound like a “gunshot” to the operator or to bystanders. When such systems enter the 80-zone on the Suppression Rating scale on a reciprocating weapon, the signatures have a large proportion of audibly discernable mechanical noise. 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 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.
6.205.3 Review Summary: CAT BEN on a Beretta 21A Subcompact Semiautomatic Pistol
When paired with the Beretta 21A subcompact semiautomatic pistol and fired with CCI SV .22 LR ammunition, the CAT BEN achieved a composite Suppression Rating™ of 79.6 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 Combat Application Technologies CAT/BEN is a subcompact “micro” rimfire silencer that exhibits enhanced performance characteristics for its size, including on short-barrel semiautomatic pistols with subsonic ammunition. It is rated for 5.7x28mm, and is only 4.28 inches long. At the time of evaluation, there have been no other rimfire silencers in the public research pedigree that exhibit the performance of the CAT BEN in the same length envelope in this combustion regime. The silencer is sealed; its monolithic DMLS titanium body may be cleaned with a variety of chemical solutions.
Like the longer CAT SR, the CAT BEN 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 high early-time flow rate from the CAT BEN does pay dividends in reducing ejection port blast hazard to the weapon operator with the Beretta 21A pistol.
The CAT BEN is short and light weight. The test specimen evaluated by PEW Science weighs approximately 3.8 ounces. The slightly higher mass than the CAT SR somewhat reduces resonance from semiautomatic action noise mechanical impact. In general, at these levels of suppression, pistol action noise from slide closing may sound different to the user depending on silencer mass.
Other than total performance and FRP suppression performance when compared to the full-size CAT SR, the rest of the suppression performance attributes of the CAT BEN, including combustion propagation consistency and back pressure, are similar due to the application of similar technology. There are no other silencers evaluated by PEW Science, to date, that exhibit the suppression performance of the CAT BEN in the same length envelope, in this combustion regime. Like the short configuration of the Rugged Oculus, the CAT BEN may be considered a “micro” rimfire silencer.
Servicing the CAT BEN is accomplished by soaking with the user’s cleaning solution of choice to remove lead fouling. 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/BEN, 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/BEN performance metrics depend upon suppressing a subsonic rimfire cartridge on a subcompact semiautomatic rimfire pistol, which is a difficult task. 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 pistol 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.
