SSS.6.2 - Rugged Oculus and the Beretta 21A (Free Version)
/Rugged Suppressors Oculus on a Beretta 21A Subcompact Semiautomatic Pistol
The Oculus is manufactured by Rugged Suppressors. It is a 22 caliber rimfire silencer, intended to suppress .22LR, .22WMR, .17HMR, .17WSM, and 5.7x28mm. It has a 1.06-inch diameter and is modular, in that it can be configured in the user’s choice of two lengths. The length in the long configuration is 5.25 inches and the length in the short configuration is 3.25 inches. The silencer is constructed entirely of 17-4PH stainless steel (tube and baffles) and weighs 6.9 ounces or 4.3 ounces in the long or short configurations, respectively. The Oculus can be obtained from Silencer Shop.
PEW Science Addendum: The original white paper, published 09-APR-2020, examined the performance of the Rugged Oculus in both long and short configurations on the Beretta 21A subcompact semiautomatic pistol with a random assortment of .22LR ammunition.
This addendum presents testing and analysis results for the same configurations using CCI Standard Velocity 40gr .22LR ammunition. The purpose of this addendum is to provide standardized testing and analysis results for future performance comparisons with the Beretta 21A host weapon and to further highlight the importance of ammunition type as a variable in suppressed small arm sound signature severity.
The addendum is notated 6.2.A.X, where ‘X’ is an addition. The contents of the original white paper (6.2.X) follow this addendum, unedited.
Summary: When paired with the Beretta 21A semiautomatic pistol and fired with CCI Standard Velocity 40gr .22LR ammunition in its long configuration, the Rugged Oculus achieved a Suppression Rating™ of 77.3 in PEW Science testing. In its short configuration with the same host weapon and the same ammunition, the Oculus achieved an average Suppression Rating of 47.8.
6.2.A Oculus Sound Signature Test Results - Addendum
A summary of the principal Silencer Sound Standard performance metrics of the Oculus in its long and short configurations are shown in Table 1A and Table 2A, respectively. 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 1A. Rugged Oculus (Long Configuration) Sound Metric Summary
Table 2A. Rugged Oculus (Short Configuration) Sound Metric Summary
6.2.A.1 SOUND SIGNATURES AT THE MUZZLE - ADDENDUM
Real sound pressure histories from two 6-shot tests 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, here.
The primary sound signature pressure histories for all 6 shots with the long configuration and short configuration are shown in Figures A1 and A3, respectively. The real sound impulse (momentum transfer potential) histories from the same 6-shot tests are shown in Figures A2 and A4, respectively.
Fig A1. Rugged Oculus Long Configuration Subcompact Semiautomatic Pistol Muzzle Sound Pressure Signature, CCI Standard Velocity 40gr. Ammunition
Fig A2. Rugged Oculus Long Configuration Subcompact Semiautomatic Pistol Muzzle Sound Impulse Signature, CCI Standard Velocity 40gr. Ammunition
Fig A3. Rugged Oculus Short Configuration Subcompact Semiautomatic Pistol Muzzle Sound Pressure Signature, CCI Standard Velocity 40gr. Ammunition
Fig A4. Rugged Oculus Long Configuration Subcompact Semiautomatic Pistol Muzzle Sound Impulse Signature, CCI Standard Velocity 40gr. Ammunition
6.2.A.3 Addendum Summary: Rugged Oculus and the Beretta 21A with CCI SV Ammunition
When paired with the Beretta 21A semiautomatic pistol and fired with CCI Standard Velocity 40gr .22LR ammunition in its long configuration, the Rugged Oculus achieved a Suppression Rating™ of 77.3 in PEW Science testing. In its short configuration with the same host weapon and the same ammunition, the Oculus achieved a Suppression Rating of 47.8.
Observations given in the original white paper regarding the performance of the Rugged Oculus on this platform, in both of its configurations, hold true. Consistency of the measured signatures improved, significantly, when tested with CCI Standard Velocity ammunition, as postulated. However, the following should be noted after conducting this additional testing:
It was previously postulated that a random assortment of .22LR ammunition provided a so-called “worst case” signature severity bounding for the performance of the Rugged Oculus on this weapon system, in both its configurations. This is somewhat true, in that both muzzle and ear Suppression Ratings with the long configuration did increase when using CCI Standard Velocity ammunition. However, both the muzzle and ear Suppression Ratings with the short configuration decreased when using the standard ammunition type. As the ammunition used in the original testing of both configurations was truly random and unknown, it is not possible to conclude the exact cause of the signature discrepancies. However, it is important to note that there are somewhat significant raw pressure and impulse amplitude differences noticed between the two tests of the short configuration. It is likely that the random assortment of ammunition used in the original short configuration test contained significantly underpowered ammunition. While it is unusual that the results from the tests of the long configuration were similar with both standard and random ammunition, it is coincidence.
The tests summarized in the original white paper were conducted in an ad hoc fashion for the purposes of industry demonstration and to frame the concept of suppressed small arm signature severity spectra; the variation in possible performance when using the same silencer on a variety of host weapons. The juxtaposition of the performance of the Rugged Oculus on the 16-in barrel bolt-action rifle and the 2.4-in barrel subcompact semiautomatic pistol is significant and possesses a high degree of data utility for the state of practice. Future PEW Science research, presented both publicly and privately, will most often utilize the CCI Standard Velocity .22LR 40gr loading for testing. It is important to note, as highlighted in (1), that ammunition choice is not always conservative. Care must be taken not to extrapolate test data and analysis to other ammunition and host types without adequate information; erroneous conclusions may occur. This may result in potentially unconservative dosing outcomes, posing higher risk to the system operator and bystanders.
This research addendum is made possible by contributions from PEW Science Members. Thank you for your support!
The original white paper publication follows:
Rugged Suppressor Oculus on a Subcompact Pistol with Random .22LR Ammunition
The previous review examined Oculus suppression performance on a bolt action rifle with a 16-in barrel. That configuration, with the CZ452, represents a high end of suppression performance exhibited by the Oculus when using CCI Standard Velocity ammunition. In this review, single-test results using the Rugged Oculus on the subcompact Beretta 21A semiautomatic pistol are shown. The subcompact 21A pistol is chambered in .22LR, like the CZ452. However, the 21A possesses a 2.4-inch barrel and functions with semiautomatic operation. Results with both the long and short configurations of the Oculus on the Beretta 21A are shown; this time, with a random assortment of .22LR ammunition. This review highlights a lower end of suppression performance with the Oculus, and a case illustrating a “plinking” configuration with non-standardized ammunition selection.
Summary: When paired with the Beretta 21A semiautomatic pistol and fired with a random assortment of .22LR ammunition in its long configuration, the Rugged Oculus achieved an average Suppression Rating™ of 75.5 in PEW Science testing. In its short configuration with the same host weapon and another random batch of ammunition from the same assortment, the Oculus achieved an average Suppression Rating of 59.1.
6.2.1 Oculus Sound Signature Test Results (Long Configuration)
A summary of the principal Silencer Sound Standard performance metrics of the Oculus in its long configuration 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 PEW Science testing, research, and development with a membership, here. State-of-the-art firearm sound signature testing and research conducted by PEW Science is supported by readers like you.
Table 1. Rugged Oculus (Long Configuration) Sound Metric Summary
6.2.1.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 8-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 8 shots are shown in Figure 1a. A zoomed-in timescale displays the region of peak sound pressure in Figure 1b. The real sound impulse (momentum transfer potential) histories from the same 8-shot test are shown in Figure 2. Again, full and short timescales are shown.
Fig 1a. Rugged Oculus Full Configuration Subcompact Semiautomatic Pistol Muzzle Sound Pressure Signature, 20-SEP-2019
Fig 1b. Rugged Oculus Full Configuration Subcompact Semiautomatic Pistol Muzzle Sound Pressure Signature, Small Time Window 20-SEP-2019
Figure 2a. Rugged Oculus Full Configuration Subcompact Semiautomatic Pistol Muzzle Sound Impulse Signature, 20-SEP-2019
Figure 2b. Rugged Oculus Full Configuration Subcompact Semiautomatic Pistol Muzzle Sound Impulse Signature, 20-SEP-2019
Figure 1 shows no sound pressure regime first-round-pop (FRP); shot 2 possesses the highest peak sound pressure (130.5 dB). Figure 2, however, shows a clear decrease in peak positive-phase sound impulse after Shot 2. PEW Science note: 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. In this case, multiple (unknown) ammunition types may have contributed to the impulse shift seen after Shot 2; however, continued environmental changes in the silencer after Shot 2 may also be partially responsible for the measured changes.
6.2.2 Oculus Sound Signature Test Results (Short Configuration)
A summary of the principal Silencer Sound Standard performance metrics of the Oculus 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 6.2.1, 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 PEW Science testing, research, and development with a membership, here. State-of-the-art firearm sound signature testing and research conducted by PEW Science is supported by readers like you.
Table 2. Rugged Oculus (Short Configuration) Sound Metric Summary
6.2.2.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 7-shot test acquired with PEW-SOFT™ are shown below. The weapon system exhibited a malfunction with one of the eight rounds loaded, and that round was not fired in this test. 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, here.
The primary sound signature pressure histories for all 7 shots in the short configuration are shown in Figure 3a. A zoomed-in timescale displays the region of peak sound pressure of the most severe shot in Figure 3b. The real sound impulse (momentum transfer potential) histories from the same 7-shot test are shown in Figure 4a. This time, the significant impulse discrepancy is illustrated between two shots in Figure 4b.
Fig 3a. Rugged Oculus Short Configuration Subcompact Semiautomatic Pistol Muzzle Sound Pressure Signature, 20-SEP-2019
Fig 3b. Rugged Oculus Short Configuration Subcompact Semiautomatic Pistol Muzzle Sound Pressure Signature, Short Time Window, 20-SEP-2019
Fig 4a. Rugged Oculus Short Configuration Subcompact Semiautomatic Pistol Muzzle Sound Impulse Signature, 20-SEP-2019
Fig 4b. Rugged Oculus Short Configuration Subcompact Semiautomatic Pistol Muzzle Sound Impulse Signature, Peak Comparison, 20-SEP-2019
As was shown in the tests of the long configuration, a view of the sound pressure regime in Figure 3 shows no FRP; again, Shot 2 possesses the highest peak sound pressure (139.7 dB). Figure 4, however, shows that the fastest rise to peak energy does, in fact, occur in Shot 1 with Shot 2 possessing the highest peak impulse. The random ammunition is postulated to have contributed to the discrepancies in measured impulses shown in Figure 6a; there seems to be at least 4 different ammunition types during the test, as observed by similar impulse peaks and timings:
Shot 1 and Shot 3
Shots 4 and 5
Shots 6 and 7
Shot 2 is the outlier, having timing characteristics of group (2) but in the magnitude regime of group (1)
PEW Science note: Ammunition can vary; CCI Standard Velocity is often the preferred ammunition for .22LR silencer testing for this reason, as it is typically relatively consistent. This review illustrates the possible variance in sound signatures that can occur with other ammunition. This test demonstrates a literal grab-bag!
6.2.3 Review Summary: Rugged Oculus and the Beretta 21A
When paired with the Beretta 21A semiautomatic pistol and fired with a random assortment of .22LR ammunition in its long configuration, the Rugged Oculus achieved an average Suppression Rating™ of 75.5 in PEW Science testing. In its short configuration with the same host weapon and another random batch of ammunition from the same assortment, the Oculus achieved an average Suppression Rating of 59.1.
PEW Science Subjective Opinion:
The Rugged Oculus is a high performing rimfire silencer. The ability to configure the silencer differently based upon suppression and length preferences may be attractive to some users. The silencer is not the lightest on the market, but is extremely durable. With stainless steel baffles, cleaning of lead fouling may be accomplished with an ultrasonic cleaner or harsh solvents that may damage less resilient materials such as aluminum.
The sometimes advertised “no first round pop” of the Oculus does hold some factual value, in that the pressure regime often shows no discernible FRP, but Silencer Sound Standard metrics show otherwise. This should not be surprising, as the environmental differences of the silencer internal volume prior to the first shot and after the first shot will be different unless employing a novel gas-displacement apparatus to inject a material other than air into the silencer, or using some kind of ablative media.
In this review, the Oculus was given an exceedingly difficult task - it suppressed a random variety of rimfire ammunition (literally sourced from a grab-bag brought to the range by an observer) and did so on a short barreled host weapon. With a 2.4-inch barrel, the Beretta 21A illustrates one of the more difficult rimfire pistols to suppress. This review should give the reader a non-typical upper bound of loudness for a high performance rimfire silencer like the Oculus and gives an example of real compact rimfire silencer performance on a compact host by examining the performance in its short configuration.
The Oculus still performs well in this “worst case” configuration and many users will find that it can be used comfortably without hearing protection. However, it is important to note that a Suppression Rating of 59.1 indicates a significantly different sound signature than was observed with the same silencer on a weapon platform with a longer barrel in Review 6.1.
