SSS.6.172 - Rugged Obsidian 9 and the HK P30L
/Rugged Obsidian 9 on the HK P30L Full-Size Semiautomatic Pistol
The Obsidian 9 is designed and manufactured by Rugged Suppressors. It is a 9mm centerfire pistol silencer, intended to suppress the 9x19mm cartridge from semiautomatic handguns and submachine guns. The Obsidian 9 is a modular silencer with a 1.38-inch primary diameter, and its long configuration is 8 inches in length. In its short configuration, the silencer is 5.1 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 Obsidian 9 is compatible with its own pistons, as well as those from SilencerCo. Performance and operability differentials may occur with varying the piston type. Direct-thread and 3-lug adapters are also available from Rugged for use with the Obsidian 9. The mount section of the primary tube and baffles are constructed from heat treated stainless steel, while the main and extension tubes, along with the end cap, are constructed from aluminum. The silencer is user-configurable, and with the piston and spring installed, weighs 13 ounces in the long configuration and 8.8 ounces in the short configuration, as tested. The Obsidian 9 can be obtained from Silencer Shop.
This Sound Signature Review contains test results and analysis for two silencer configurations in two tests. Test data was generated using the Rugged Obsidian 9 (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 tests.
Section 6.172.1 contains the Obsidian 9 test results and analysis in the long configuration.
Section 6.172.2 contains the Obsidian 9 test results and analysis in the short configuration.
Section 6.172.3 contains Suppression Rating comparisons of the Obsidian 9 with the CAT SC, 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 6.172.4 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 Rugged Obsidian 9 achieved a Suppression Rating™ of 58.3 in PEW Science testing. In its short configuration with the same host weapon and the same ammunition, the Obsidian 9 achieved a Suppression Rating of 30.6. 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
6.172.1 Rugged Obsidian 9 (Long) Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Rugged Obsidian 9 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. Rugged Obsidian 9 (Long Configuration) Sound Metric Summary
6.172.1.1 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 Rugged Obsidian 9 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 Shots 1 through 5.
Fig 1a. Rugged Obsidian 9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 1b. Rugged Obsidian 9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Sound Pressure Signature
Figure 2a. Rugged Obsidian 9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
Figure 2b. Rugged Obsidian 9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
The Rugged Obsidian 9 is is the dedicated 9mm silencer in the Obsidian silencer product line. The 9mm semiautomatic pistol suppression performance of the Rugged Obsidian 45 was previously evaluated in report 6.7.
The Obsidian 9 is half an inch shorter than the Obsidian 45 in the long configuration, and over 1.5-inches shorter in the short configuration. Other than those differences, the exterior envelopes of the silencer are similar. Other similarities between the Obsidian 9 and Obsidian 45 are:
Both silencers use traditional curved-cone baffle geometry with traditional mill-cut notches. Like most Rugged silencers, there is stepped geometry present on the baffle throats.
Both silencers are modular, in that the distal section can be removed, the end cap reinstalled, and a shorter, lighter-weight configuration is created at the expense of sound suppression performance.
Neither silencer possesses venting or any other purposeful early-time blast impulse accumulation reducing features to lower overall backpressure for use on semiautomatic firearms.
It is important to note that due to the factors in (3), ejection port blast hazards when using the Obsidian series will be higher than with more advanced silencers, regardless of their strong muzzle suppression performance. This is also the case with the Obsidian 45 on 9mm pistol hosts, which highlights the limited efficacy of backpressure reduction through over-bore.
The muzzle blast suppression performance of the Rugged Obsidian 9 is very high. Several observations in the above test data support this conclusion:
Relatively low gross pressure amplitude with ramped onset (relatively slow rise time, Fig. 1a and 1b).
Significantly suppressed coupled jetting (Fig. 1b).
Low rate of impulse accumulation prior to maximum, even without breech pressure leak phenomena (Fig. 2a).
In gross behavior, the long configuration of the Rugged Obsidian 9 exhibits characteristics very similar to the AAC Ti-RANT 9M-HD in its long configuration (6.118), though with higher performance. The Obsidian 9 controls both first-round-pop (FRP) and general blast pressure propagation in a superior fashion to the AAC silencer. The higher level of gross suppression performance is reflected in its higher muzzle Suppression Rating; the risk to bystanders adjacent to the weapon system is somewhat reduced when using the Obsidian 9.
PEW Science Research Note 1: Though the FRP suppression performance of the Rugged Obsidian 9 is superior to that of the AAC Ti-RANT 9 series in both relative severity to subsequent shots and absolute risk metrics, it is by no means minimal. Bystanders adjacent to the weapon system may experience a signature from the Obsidian 9 that is over 80% more severe during the first shot than during subsequent shots, on average, with full power ammunition. This type of FRP suppression performance deficiency is relatively commonplace among traditional centerfire handgun silencers. Notable cases of excellent FRP reduction include silencers such as the Resilient Suppressors RSP (6.87), the SWR Trident-9 (6.8), and the CAT SC (6.162). The aforementioned statement is based upon relative FRP performance, not absolute suppression. The reader is encouraged to examine Figure 9 in this report for absolute suppression metrics as well as the Rankings Section of the Standard. All three of the aforementioned silencers employ some method of ancillary flow path geometry, either in early time, late time, or both. This type of geometry may also contribute to FRP reduction, not only to high flow rate. The case study of the high back pressure Trident-9, which uses original Omega Baffles is a pertinent example of this.
PEW Science Research Note 2: The Rugged Obsidian 9 is an excellent example of traditional centerfire pistol silencer technology that has been refined for high performance. In some ways, the performance of the Obsidian 9, particularly in the long configuration, far exceeds that of many other silencers on the platform, and it does so with extremely simple design geometry. Its muzzle Suppression Rating on the tested host weapon exceeds that of every silencer in the aforementioned AAC Ti-RANT 9 series. The Obsidian 9 is also slightly shorter than the legacy SWR Trident-9, and still outperforms that model. Notably, the Rugged Obsidian 9 outperforms the CGS MOD 9 (6.6) and does so in overall suppression, FRP reduction, and with lower backpressure.
PEW Science Research Note 3: Just as the the Obsidian 9 is an example of a high degree of performance refinement, it is also an example of total system performance stagnation in pistol silencer design history. With no features to increase early time flow rate, the operator risk reduction performance potential of the Obsidian 9 is self-limited. On closed-breech weapons, or weapons in which the chamber may be closed or extraction delayed by a relatively significant amount of time, this performance detriment is of less significance. However, almost all known traditional combat handguns using a modified Browning tilting-barrel action exhibit lock times unfavorable to this backpressure generation. Back pressure in a silencer design is not blowback. Back pressure is caused by blast load impulse accumulation above given thresholds in various parts of the silencer, and therefore occurs in multiple time regimes. Blast load impulse accumulation is the result of not only pressure stagnation, but additive load reflections. Without clearing (venting), impulse will continue to accumulate during the time regimes of interest. Matching the time regime of clearing to the requisite weapon function sequence is paramount to the design process used by suppressed small arm weapon system developers (developers of the whole systems; silencers and hosts.)
There do exist centerfire pistol silencers which possesses designs that take into account the physical realities discussed above. 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 aforementioned Resilient Suppressors RSP, and adjacently, the Inert Haze Ti-P (6.145). These three silencers do reduce operator hazard in the free field, particularly with respect to their low(er) muzzle (bystander) Suppression Ratings. The challenge for pistol silencer designers is to achieve a high degree of operator protection combined with a high degree of gross pressure field suppression. At the time of this article publication, the strongest performance potential demonstrating progress toward achieving that goal has been demonstrated by the aforementioned CAT SC. As with rifle suppression, the evolution of hybrid designs continues, and is expected to continue to increase performance dividends on semiautomatic host weapons. Over-bore (using a silencer with a bore aperture larger than required for cartridge-specific use) is seldom effective at reducing operator hazard, both due to gross pressure field suppression compromise and early time blast load reflections that have little to do with bore size.
PEW Science Research Note 4: 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 75 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 5: Note that the muzzle Suppression Rating of the Rugged Obsidian 9 in its long configuration used on the full-size HK P30L semiautomatic handgun test host is 58.1 and the shooter’s-ear Suppression Rating is 40.5; 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.
6.172.1.2 SOUND SIGNATURES AT SHOOTER’S EAR
Real sound pressure histories from the same 6-shot test of the Rugged Obsidian 9 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. Rugged Obsidian 9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Pressure Signature
Figure 3b. Rugged Obsidian 9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Pressure Signature, Short Time Window
Figure 4a. Rugged Obsidian 9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Impulse Signature
Figure 4b. Rugged Obsidian 9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Impulse Signature Peaks
As discussed in previous test reports, there is a persistent observed phenomenon present in centerfire pistol silencer signatures when using the HK P30L standard test host. 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 the CAT SC report, it was proven 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 occurred; regardless of long or short silencer configuration, as well. And, as expected, they also occur with the Rugged Obsidian 9 in both configurations (see Member Section 6.172.2.2). These shocks can be seen in Figure 3b at approximately 28.5 ms. They occur in every shot other than Shot 2 and Shot 4. While this shows higher prevalence to occur in this test compared to the tested of low(er) back pressure silencers, and there is most likely influence on blast chamber impulse accumulation to the phenomena, no silencer tested has prevented the phenomena from occurring on this host weapon with full power test ammunition.
PEW Science Research Note 5: The early-time host-driven behavior of the Obsidian 9 and CAT SC are where the similarities in behaviors end. The signature at the operator’s head with the Obsidian 9 is very similar to that generated from the AAC Ti-RANT 9 series. There is an indicator that is plainly visible in the test data, highlighting distinct weapon functional difference, and that is the higher degree of mechanical shock (Fig. 3b, ~34.5 ms). Ejection port blast and mechanical shock are elevated with the Obsidian 9 due to its design. The design intent of the system is to maximize gross pressure field suppression through ultra-optimized traditional baffle geometry. That design goal, by its nature, results in this behavior.
PEW Science Research Note 6: Relative FRP severity differential at the operator’s head is postulated to be extremely noticeable to the operator, and more severe than to bystanders adjacent to the weapon system. This is likely due to the already significant muzzle blast FRP being coalescing with severe ejection port blast loads from the system’s higher back pressure.
PEW Science Research Note 7: It is very important to understand that the severity of the weapon system signature with the long configuration of the Obsidian 9 on this host will be almost identical to that of the Obsidian 45 on this host. However the bystander risk (characterized by the muzzle Suppression Rating) of the two silencers are different. The practical implications of this are that a user or bystander may interpret the Obsidian 9 as “quieter,” in general; to iterate, the hearing damage risk potential to the operator may be the same with the Obsidian 9, even though it may be interpreted as “quieter.” This may lead the user to believe they are more protected when using the Obsidian 9 than the Obsidian 45, when that conclusion may be incorrect. This phenomenon occurs due to late time wave propagation being more severe with the Obsidian 45. It is more noticeable to the shooter in the free field, but not more hazardous.
The logic above should always be used. The Suppression Rating metrics are absolute and quantify acute hazard not “subjective loudness.”
The difference in performance, to the weapon operator, between the Rugged Obsidian 9 and other silencers, is significant in the free field. Outside of the free field, near reflecting surfaces, the performance differential may be more (or less) significant, as its holistic pressure field is highly suppressed, but ejection port blast loads can still reflect from surrounding surfaces.
The performance of the Rugged Obsidian 9 in its long configuration on a pistol, at the shooter’s ear, is driven by both muzzle signature and ejection port signature. When the distal (front) section of the silencer is removed, and the silencer is changed to its short configuration, the signature balance changes. Back pressure is somewhat reduced, but so is muzzle suppression performance, by a significant margin. This is demonstrated in the test summarized in the following section.
6.172.2 Rugged Obsidian 9 (Short) Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Rugged Obsidian 9 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 6.172.1, 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. Rugged Obsidian 9 (Short Configuration) Sound Metric Summary
6.172.2.1 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 Rugged Obsidian 9 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. Rugged Obsidian 9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 5b. Rugged Obsidian 9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 6a. Rugged Obsidian 9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
Fig 6b. Rugged Obsidian 9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
The removal of the distal section of the Rugged Obsidian 9 to adapt it from its long to short configuration significantly 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).
Very high amplitude initial coupled jetting (Fig. 5b).
Immediate and severe primary jetting after (3) with significant 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).
Less significant FRP divergence in both pressure and impulse space (gross suppression is too low, in general, for FRP severity differential to manifest in typical ways). One key indicator illustrating that FRP is still present is the coupled jet rise time differential (Fig. 5b), as well as the requisite peak amplitude differentials in early time from this jetting, in both pressure space and impulse space (Fig 6).
The above differences are relatively typical when removing a substantial section from the distal end of a silencer. And, because of the conventional technology used in the Obsidian 9, performance detriments are no longer masked by baffle quantity. To be clear, the silencer in its short configuration is only 5.1 inches long. But for context, the SilencerCo Omega 9K (6.153) is 4.9 inches long, the HUXWRX CASH 9K (6.96) is 5.4 inches long, and the short configuration of the CAT SC (6.162) is 5.5 inches long. The Obsidian 9 in its short configuration is outperformed by all of these silencers in both bystander and operator hazard reduction, by a significant margin.
PEW Science Research Note 8: The muzzle Suppression Rating of the Rugged Obsidian 9, in the free field, changes from 58.1 to 21.5 when changing from its long to short configuration. This performance change, spanning three Suppression Rating Performance Categories, indicates that the hazard adjacent to the weapon system when the two different configurations of the silencer are used are significantly different. In no circumstances should users assume that the Obsidian 9 performs similarly in its short configuration to how it performs in the long configuration, on host weapons such as the one tested herein, with full power self defense ammunition. Any performance similarity would be purely coincidental and driven by other factors such as excessive barrel length with a locked breach, and extremely underpowered ammunition, outside the bounds of practical defensive use. The suppression performance of the Obsidian 9 in the short configuration is so low compared with other silencers tested in the pedigree that the very nature of the sound field will be interpreted by bystanders as "significantly different” and in all likelihood, subjectively "significantly louder and more intense.”
PEW Science Research Note 9: Despite its relatively low suppression performance, the short configuration of the Rugged Obsidian 9 provides significantly more protection to bystanders than an unsuppressed centerfire combat handgun. This is reflected in its Suppression Ratings at the muzzle and ear. Readers should note that a single-peak transient measurement from a blast overpressure wave does not contain enough information to accurately inform system response, and therefore, does not contain information to accurately inform hazard. As shown in Table 2, the average peak transient pressure 1.0 meter left of the muzzle end cap of the short configuration of the Obsidian 9 is 148.7 dB. When fielded on the standard short barrel 5.56x45mm centerfire MK18 rifle, the Surefire SOCOM556-RC3 (6.151) produces an average peak transient pressure at the same location of 149.0 dB. Not only does the RC3 provide a less hazardous environment to operators and bystanders, it does so at slightly higher peak pressure. There exist a multitude of examples in the research pedigree for investigation. Even if the peak transient pressure is comparable in average gross amplitude, the frequency, phase, and duration components of the entire measured blast load histories differ significantly. A semiautomatic pistol, semiautomatic rifle, and other weapon systems produce completely different signatures when suppressed with silencers. Suppressed small arm weapon systems do not enjoy wave shape characteristic commonality with unsuppressed weapon systems, and even if they did, only partial commonality would be possible due to the nature of small arm weapon cartridge types. PEW Science highly recommends the use of the Suppression Rating to inform risk of hazard, for these reasons, as discussed in the Silencer Sound Standard.
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.
The FRP on this platform, with the short configuration of the Obsidian 9 produces a much lower severity differential when compared to subsequent shots than does the long configuration of the silencer. This is primarily due to the extremely high distal flow rate. 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 10: 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 Rugged Obsidian 9.
6.172.2.2 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 Rugged Obsidian 9 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. Rugged Obsidian 9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Pressure Signature
Figure 7b. Rugged Obsidian 9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Pressure Signature
Figure 8a. Rugged Obsidian 9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Ear Sound Impulse Signature
Figure 8b. Rugged Obsidian 9 (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). However, the amplitude of the accumulation is significantly higher. This is due to muzzle blast.
PEW Science Research Note 10: While ejection port blast does play a role in operator hazard with the short configuration of this silencer, the muzzle blast is so severe that wave coalescence produces signature components that are simply too violent at the operator’s head for typical hazard reduction efficacy to be achieved. Note that coupled jet and almost mirrored primary jetting (with severe rarefaction) in Figure 7b. These are muzzle driven events, and they are occurring in early time, not late time. Therefore, acute hazard is being increased, and that is reflected in the decreased shooter’s ear Suppression Rating with the short configuration of the silencer. Note the extremely pronounced impulse plateau at approximately 30 ms in Figure 8b. This is driven by severe muzzle blast wave coalescence.
The early-time shock dynamics remain constant. Therefore, the same breech pressure leaks present. As previously stated in 6.172.1.2, even with the extremely high early-time flow rates, these short duration shock loads from the weapon breach still occur; regardless of long or short silencer configuration. Their subsequent impulse accumulations are shown in Figure 8; relatively consistent for a seemingly inconsistent host weapon combustion propagation phenomenon.
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 different hearing damage risk potential with the two silencer configurations.
PEW Science Research Note 11: 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. However, when it does change, it is important to understand that the acute hazard to the operator is changing, and not necessarily the gross sound field overall “loudness.” The Rugged Obsidian 9 in its short configuration is likely considered “louder” than in its short configuration, but that is not only due to the increase in acute hazard to the operator (lower shooter’s ear Suppression Rating), it is also due to the gross decrease in muzzle Suppression Rating. The detailed Suppression Ratings (muzzle and ear) quantify hearing damage risk to adjacent bystanders and the shooter, 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 of centerfire pistol silencer configurations on the HK P30L semiautomatic pistol.
6.172.3 Suppression Rating Comparison (Subsonic 9x19mm from the HK P30L)
Figure 9 presents a comparison of the PEW Science Suppression Ratings of the Rugged Obsidian 9 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 Rugged Obsidian 9 in both long and short configurations with the CAT SC, 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 8-in long configuration, the Rugged Obsidian 9 provides high gross pressure field suppression performance on a semiautomatic 9mm pistol. In gross suppression, it is one of the highest performers tested. The most refined and mature iteration of the AAC Ti-RANT 9; the Ti-RANT 9M-HD in its long configuration (6.118), is outperformed by the Obsidian 9. The Obsidian 9 controls both first-round-pop (FRP) and general blast pressure propagation in a superior fashion to the AAC silencer. This level of pure suppression performance differential is notable. The long configuration of the Obsidian 9 also outperforms the longer 8.6-in Rugged Obsidian 45, and it does so due to bore size optimization. Despite this performance increase with the 9mm-dedicated Obsidian, the operator hazard reduction (shooter’s ear Suppression Rating) is almost identical between the two models. This is due to the lack of back pressure reducing features in the silencer models; any benefit of reduced muzzle blast wave coalescence from the Obsidian 9 when compared to the Obsidian 45 is offset by the more severe ejection port blast wave coalescence at the operator’s head.
Though the FRP suppression performance of the Rugged Obsidian 9 is superior to that of the AAC Ti-RANT 9 series in both relative severity to subsequent shots and absolute risk metrics, it is by no means minimal. Bystanders adjacent to the weapon system may experience a signature from the Obsidian 9 that is over 80% more severe during the first shot than during subsequent shots, on average, with full power ammunition. Please refer to Research Note 1.
PEW Science Research Note 12: It is very interesting to note that the short configuration of the Obsidian 45, while not exhibiting the gross suppression performance of the long configuration of the Obsidian 9, still achieves a very similar level of operator hazard reduction on this host weapon. This similarity is due to lower back pressure, without significant compromise of muzzle Suppression. To be clear, the short configuration of the Obsidian 45 still produces a more severe overall sound field. However the acute hazard to the weapon operator is similar to that of the long configuration of the Obsidian 9 in the free field.
Other silencer configurations that produce similar operator hazards in the free field include the SilencerCo Omega 9K (6.153), the Inert Haze Ti-P (6.145), and some variations of the AAC Ti-RANT 9 (both long and short). Operator hazard is driven by complex blast load phenomena and ejection port blast loads will influence operator hazard.
PEW Science Research Note 13: When attempting to reduce back pressure to decrease the severity of ejection port blast to the operator, the method of reduction has direct influence on performance efficacy. By simply removing distal section(s) of the silencer, like is the case with the short configuration of the Rugged Obsidian 9, muzzle blast becomes so severe that it overwhelms the operator signature. This results in the most acute operator hazard tested (lowest shooter’s ear Suppression Rating) on this platform. This information may be valuable to users with both Obsidian 9 and Obsidian 45 silencers; the short configuration of the Obsidian 45, though longer than the short configuration of the Obsidian 9, provides superior suppression performance by every measurable metric. Some other silencers achieve better performance from back pressure reduction through distal shortening, though they are somewhat longer than the 5.1-inch short Obsidian 9.
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 the aforementioned Inert Haze Ti-P. Their muzzle Suppression Ratings suffer due to higher distal flow rate. The challenge for pistol silencer designers is to achieve a high degree of operator protection combined with a high degree of gross pressure field suppression. At the time of this article publication, the strongest performance potential demonstrating progress to achieving that goal has been achieved by the aforementioned CAT SC (6.162). As with rifle suppression, the evolution of hybrid designs continues, and is expected to continue to increase performance dividends on semiautomatic host weapons. Over-bore (using a silencer with a bore aperture larger than required for cartridge-specific use) is seldom effective at reducing operator hazard, both due to gross pressure field suppression compromise and early time blast load reflections that have little to do with bore size.
The shooter’s ear Suppression Ratings of some silencers in Figure 9 are similar. 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 14: 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 with a higher Suppression Rating. 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.
6.172.4 Review Summary: Rugged Obsidian 9 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 Rugged Obsidian 9 achieved a Suppression Rating™ of 58.3 in PEW Science testing. In its short configuration with the same host weapon and the same ammunition, the Rugged Obsidian 9 achieved a Suppression Rating of 30.6.
As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.
PEW Science Laboratory Staff Opinion:
The Rugged Obsidian 9 is a high performance modular centerfire pistol silencer intended for multiple uses. The silencer is versatile as it may be used in two configurations (long and short). In its long configuration, its gross suppression performance is very high, though it does have relatively high back pressure. When the distal section is removed to create the short configuration, the signature suppression performance drops significantly, resulting in more acute hazard to both the operator and bystanders. Nonetheless, the short configuration of the silencer does offer significant hazard reduction over that of an unsuppressed combat handgun. The Obsidian 9 represents a popular, common example of traditional technology optimized to the limits of its efficacy.
The Rugged Obsidian 9 is an excellent example of traditional centerfire pistol silencer technology that has been refined for high performance. In some ways, the performance of the Obsidian 9, particularly in the long configuration, far exceeds that of many other silencers on the platform, and it does so with extremely simple design geometry. Its muzzle Suppression Rating on the tested host weapon exceeds that of every silencer in the AAC Ti-RANT 9 series. The Obsidian 9 is also slightly shorter than the legacy SWR Trident-9, and still outperforms that model. Notably, the Rugged Obsidian 9 outperforms the CGS MOD 9 and does so in overall suppression, FRP reduction, and with lower backpressure.
Just as the the Obsidian 9 is an example of a high degree of performance refinement, it is also an example of total system performance stagnation in pistol silencer design history. With no features to increase early time flow rate, the operator risk reduction performance potential of the Obsidian 9 is self-limited. On closed-breech weapons, or weapons in which the chamber may be closed or extraction delayed by a relatively significant amount of time, this performance detriment is of less significance.
There do exist centerfire pistol silencers which possesses designs that take into account holistic weapon system design and operation. Examples of silencers with low backpressure, intended to maximize shooter protection in the free field, include models such as the HUXWRX CASH 9K, the Resilient Suppressors RSP, and adjacently, the Inert Haze Ti-P. These three silencers do reduce operator hazard in the free field, particularly with respect to their low(er) muzzle (bystander) Suppression Ratings. The challenge for pistol silencer designers is to achieve a high degree of operator protection combined with a high degree of gross pressure field suppression. At the time of this article publication, the strongest performance potential demonstrating progress to achieving that goal has been achieved by the aforementioned CAT SC. As with rifle suppression, the evolution of hybrid designs continues, and is expected to continue to increase performance dividends on semiautomatic host weapons.
Over-bore (using a silencer with a bore aperture larger than required for cartridge-specific use) is seldom effective at reducing operator hazard, both due to gross pressure field suppression compromise and early time blast load reflections that have little to do with bore size. The long configuration of the Obsidian 9 outperforms the longer 8.6-in Rugged Obsidian 45, and it does so due to bore size optimization. Despite this performance increase with the 9mm-dedicated Obsidian, the operator hazard reduction (shooter’s ear Suppression Rating) is almost identical between the two models. This is due to the lack of back pressure reducing features in the silencer models; any benefit of reduced muzzle blast wave coalescence from the Obsidian 9 when compared to the Obsidian 45 is offset by the more severe ejection port blast wave coalescence at the operator’s head. It is very interesting to note that the short configuration of the Obsidian 45, while not exhibiting the gross suppression performance of the long configuration of the Obsidian 9, still achieves a very similar level of operator hazard reduction on this host weapon. To be clear, the short configuration of the Obsidian 45 still produces a more severe overall sound field. However the acute hazard to the weapon operator is similar to that of the long configuration of the Obsidian 9 in the free field.
The Rugged Obsidian 9 may be used with Rugged and SilencerCo pistons, as well as with other pistons following that general design pattern, though performance differential will occur. PEW Science has only evaluated the Obsidian 9 with the Rugged 13.5x1mm LH piston. The Obsidian 9 end cap and rear cap may be removed with specialized tools available from Rugged Suppressors, and direct-thread mounts and 3-lug mounts from Rugged installed. 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 construction of the Obsidian 9 is intended to be significantly robust. It is important to note that in addition to the baffles, the aft “mount” portion that threads into the main tube is constructed of stainless steel and the silencer is user-serviceable. The Obsidian 9 is intended for use on both semiautomatic and automatic host weapons. While it is intended for pistol use, it is also intended to possess requisite durability for dual-use on pistol caliber carbines. Durability of the silencer during aggressive firing schedules on fixed barrel weapons has not been comprehensively evaluated by PEW Science. Note that a fixed-barrel-spacer must be used in lieu of the inertial decoupler spring for use on fixed barrels, or the user can opt for a dedicated fixed mount.
In this review, the Rugged Obsidian 9 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.
