SSS.6.234 - Rugged Obsidian 45 and the .45ACP 1911
/Rugged Obsidian 45 on the 1911 Full-Size .45ACP Semiautomatic Pistol
The Obsidian 45 is manufactured by Rugged Suppressors. It is a 45 caliber centerfire pistol silencer, intended to suppress many cartridges with projectiles appropriately sized to travel through the bore, including .450 Bushmaster, .44 magnum, and subsonic .458 SOCOM on 16-inch barrels. It has a 1.37-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 8.7 inches and the length in the short configuration is 6.8 inches. The silencer mounts to the host firearm with an internal inertial decoupling piston assembly available in multiple standard thread pitches. Other mounts are available, including fixed mounts and an internal 3-lug mount module. The silencer’s mount section and baffles are constructed of 17-4PH stainless steel. The main tube is constructed of aluminum. The silencer is user-serviceable and weighs 12.8 ounces or 10.7 ounces in the long or short configurations, respectively. The Obsidian 45 can also use the 9mm end cap from the Obsidian 9 silencer. The Obsidian 45 can be obtained from Silencer Shop.
Silencer Hazard Maps:
The predicted personnel hazards generated by the tested weapon system in this report, in the free field, are shown in the below Silencer Hazard Maps for both the long and short configurations of the silencer. Click or tap the Maps to enlarge. Please reference Silencer Hazard Map Brief 8.1.31 for further details. The PEW-SOFT HD Blast Hazard Prediction Tool and Hazard Mapper is presented in Report 8.1.1.
Rugged Obsidian 45 (Long Configuration) 1911 Free Field Hazard Map Produced by PEW-SOFT HD Blast Hazard Prediction Tool using PEW Science Test Data
Rugged Obsidian 45 (Short Configuration) 1911 Free Field Hazard Map Produced by PEW-SOFT HD Blast Hazard Prediction Tool using PEW Science Test Data
Other Rugged Obsidian Test Reports:
The Rugged Obsidian 45 in both long and short configurations was first evaluated in Report 6.7 on a 9mm semiautomatic pistol. Similarly, the Rugged Obsidian 9 was evaluated in Report 6.172.
Summary and Table of Contents
This Sound Signature Review contains test results and analysis using the Rugged Obsidian 45 in both its long and short configurations on the standard 1911 .45ACP combat handgun with 5.5-in factory threaded barrel. Speer Lawman 230gr ammunition was used in the test. Unsuppressed combustion phenomena using the 1911 test host is presented in Report 6.227.
Section 6.234.1 contains Suppression Rating comparisons of the Rugged Obsidian 45 with other .45ACP systems, including the AAC Ti-RANT 45, as well as the KAC and B&T silencers evaluated on the HK MK23 and HK USP45 Tactical. Unsuppressed muzzle blast pressure and impulse comparisons are provided for the different weapon systems.
Section 6.234.2 contains the Rugged Obsidian 45 Long Configuration test results and analysis on the 1911.
Section 6.234.3 contains the Rugged Obsidian 45 Short Configuration test results and analysis on the 1911.
Section 6.234.4 repeats the initial summary suppression performance comparisons with additional commentary.
Section 6.234.5 contains the review summary and PEW Science laboratory staff opinions.
Summary: When paired with the 1911 full-size semiautomatic pistol and fired with Speer Lawman 230gr ammunition, the Rugged Obsidian 45 in its long configuration achieved a Suppression Rating™ of 49.5 in PEW Science testing. The short configuration of the Obsidian 45 achieved a Suppression Rating of 34.7 with the same weapon and ammunition.
9mm pistol suppression performance with the Rugged Obsidian 45 is documented in Report 6.7.
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.
6.234.1 Rugged Obsidian 45 and Legacy System Performance Summary
This report continues examination of .45ACP combustion phenomenology and its suppression from the 1911 full-size combat handgun. Previously, the AAC Ti-RANT 45 was evaluated on the 1911. Additionally, two other .45ACP combat handguns were evaluated; the HK MK23 and USP45 Tactical, both with the KAC MOD.MK23/USP developed for the SOCOM MK23 Offensive Handgun (OHG) program and the B&T Impulse-IIA SD Mk23 Rev. 03 designed to function on the same host weapons. The reader may examine the full research report on the KAC and B&T silencers here.
Unsuppressed and suppressed muzzle blast pressure histories were measured from all systems in the free field. Data reduction was performed to derive blast impulse histories as well as computations of the PEW Science Suppression Rating DRC metrics at the fielded pressure sensor locations in accordance with the Silencer Sound Standard and compatible with MIL-STD 1474E.
Suppression Rating calculations from all test data in the above research programs are summarized in Figure 1.
Fig 1. Suppression Rating Comparisons of the Rugged Obsidian 45 and AAC Ti-RANT 45 on the Remington 1911 R1 and KAC MOD.MK23/USP and B&T Impulse-IIA SD Mk23 Rev. 03 silencers on the HK MK23 and USP45 Tactical full-size semiautomatic pistols Using PEW-SOFT Test Data and PEW Science Analysis
From the above performance comparisons, the following gross conclusions can be made:
The Rugged Obsidian 45 produces the highest pure muzzle suppression performance of the group, when used in its long configuration. However, its significant back pressure results in an operator (shooter’s ear) Suppression Rating almost a full category lower than that of the legacy AAC Ti-RANT 45, and on par with that of the legacy KAC silencer on the MK23 and USP. This is a significant performance conclusion, as the Rugged Obsidian 45 is the most modern silencer of the group.
When fielded in the short configuration, the Rugged Obsidian 45 produces a risk field adjacent to the muzzle on the 1911 that is similar to that of the legacy KAC silencer on the MK23. However, its operator protection is again lacking due to low early time flow rate combined with more severe muzzle blast, and its shooter’s ear Suppression Rating drops to a range comparable to that of the legacy B&T silencer on the USP. It is important to note that the short configuration of the Rugged Obsidian 45 is a full inch shorter than the B&T silencer. Note that the long configuration of the Obsidian 45 has a length comparable to that of the AAC Ti-RANT 45.
As previously reported, the AAC Ti-RANT 45 produces exceptionally higher performance than both the KAC and B&T silencers and its operator protection is also significantly more robust than that of the Rugged Obsidian 45, regardless of Obsidian configuration.
The KAC MOD.MK23/USP silencer, and its requisite inertial-decoupling piston assemblies, provide scalable signature suppression and personnel hazard reduction performance on the two HK combat handgun host weapons. The KAC system performance is more robust than the B&T system performance.
The 1911 and HK MK23 system signatures may be suppressed to a greater degree than the HK USP45 Tactical system signature. This is a function of the longer 1911 and MK23 barrels generating lower muzzle blast pressure input into the silencer(s), as well as system lock time mechanics and dynamics.
The 1911 system lock time and barrel rifling differs from the two HK systems. This changes unsuppressed and suppressed hazards by varying ejection port blast timing and muzzle blast precursor development. Nonetheless, unsuppressed blast loads from all three weapon systems are exceedingly hazardous to personnel in the near field. Silencer use is recommended not only to minimize operational signature, but to reduce damage to the unprotected human ear. Unsuppressed blast loads from the three weapon systems were presented and examined in Report 6.227.
Detailed suppressed signature evaluations of the Rugged Obsidian 45 suppressing the .45ACP Remington 1911 R1 follow.
6.234.2 Rugged Obsidian 45 (Long Configuration) 1911 Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Rugged Obsidian 45 in its long configuration tested on the Remington 1911 R1 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 45 (Long Configuration) Subsonic .45 ACP 1911 Sound Metric Summary
6.234.2.1 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 45 in its long configuration tested on the Remington 1911 R1 are shown in Figure 4a. The sound signatures of Shot 1 and Shot 2 are shown in Figure 4b, in early time. The real sound impulse (momentum transfer potential) histories from the same 6-shot test are shown in Figure 5a. In Figure 5b, a shorter timescale is shown comparing the impulse of Shots 1 through 3.
Fig 4a. Rugged Obsidian 45 (Long Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 4b. Rugged Obsidian 45 (Long Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Sound Pressure Signature
Figure 5a. Rugged Obsidian 45 (Long Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Muzzle Sound Impulse Signature
Figure 5b. Rugged Obsidian 45 (Long Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Muzzle Sound Impulse Signature
The .45 ACP cartridge is of significantly larger diameter than the commonly fielded 9x19mm cartridge, and it also operates at a lower combustion pressure. This creates complexities in balancing distal flow rate with adequate turbulence generation and heat transfer. The larger the silencer exit aperture, the more difficult the signature suppression, all other things equal. When combustion pressure drops, some silencer technologies lose suppression efficiency to a greater degree than do others.
The overall behavior of suppressed .45 ACP systems is somewhat similar to that of suppressed 9x19mm systems, with the primary differences resulting from large bore aperture precursor flow and significant primary blast propagation in early time.
Traits observed in the above measured blast loads from the Rugged Obsidian 45 1911 test include the following:
Low blast overpressure amplitude throughout the full time regime of the complete gunshot (Fig. 4a).
Extremely controlled initial jetting with low amplitude precursor from the large bore aperture (Fig. 4b).
Significantly suppressed coupled jetting both during first-round-pop (FRP) and subsequent shots (Fig. 4b).
Minor FRP divergence occurs prior to primary jet accumulation and continues after primary blast onset though peak momentum accumulation (Fig. 5a).
Long duration blowdown is noted in both pressure space and impulse space. Blowdown momentum continues in the positive phase for significant duration (Fig. 5b).
Observations (1), (2), and (3) are typical of silencers with the high degree of muzzle suppression performance exhibited by the Obsidian 45, with observation (4) being a notable performance trait. Observation (5) is one indicator of higher system back pressure, though is not a sole indicator. In combination with other measured parameters, including the rate of momentum accumulation in Figure 5a and ejection port blast measurements in the shooter’s ear data, the high back pressure nature of the Rugged Obsidian 45 is definitive. This conclusion is reinforced below and throughout this report.
The baffle technology in the Rugged Obsidian 45 was evaluated with 9mm in Report 6.7 and is similar to the technology in the following silencers:
Rugged Obsidian 9 centerfire 9mm pistol silencer (Report 6.172)
These baffle geometries are characterized by curved and stepped cones with single mill cuts; derivatives of the legacy SWR Omega baffles, without coaxial or annular vent structures. Original Omega baffle technology evaluation is documented in Report 6.8 with the SWR Trident-9 silencer, produced between 2005 and 2011. Like all Omega baffle and simple curved cone baffle derivatives, significant back pressure is produced. In addition to gross geometric factors, initial blast load expansion, clearing, and venting in the proximal end of the silencer influences early time back pressure, thereby significantly influencing operator risk on semiautomatic combat handguns.
PEW Science Research Note 1: The above performance factors are partially responsible for the significant increase in operator hazard when fielding a long Rugged Obsidian 45 compared with the fielding of a legacy AAC Ti-RANT 45 on the same .45 ACP pistol. Though the Ti-RANT 45 uses optimized K-baffle geometry, its dual-layer annular porting array in the proximal section of the silencer produces significantly different blast dynamics than the Rugged Obsidian line of pistol silencers. In all PEW Science Laboratory internal research (IR) testing, the Obsidian 45 produces significantly more intense ejection port blast loads than the Ti-RANT 45. PEW Science IR testing has been conducted with various full size semiautomatic .45ACP handguns, including the HK MK23, USP45 Tactical, FN FNX-45 Tactical, Remington 1911 R1, and others. IR results demonstrate pervasive ejection port blast hazards with the Obsidian 45 in both the long and short configurations, regardless of test host weapon. Note that only full power subsonic .45ACP ammunition is used in PEW Science testing. It is possible that reduced power ammunition loads reduce ejection port blast hazards, but the relative nature of these performance conclusions should hold, regardless. The only reason the back pressure of the Obsidian 45 doesn’t overwhelm operator risk on a 9mm combat handgun is due to significant over bore for the cartridge. This phenomenon was explored in the Obsidian 9 test report. Back pressure still played a role, and further 9mm pistol silencer evaluations of the CAT SC (6.162) and Dead Air Mojave 9 (6.177) again proved that late time back pressure reduction from over bore, alone, is unable to compensate for high early time back pressure when suppressing semiautomatic handguns. PEW Science research definitively concludes that early time flow rate is of paramount importance for operator blast overpressure risk reduction on reciprocating small arm weapon systems.
PEW Science Research Note 2: On closed-breech weapons, or weapons in which the chamber may be closed or extraction delayed by a relatively significant amount of time, high silencer flow rate is of less significance. However, almost all modern combat handguns using a modified Browning tilting-barrel action exhibit lock times unfavorable to significant backpressure generation. The 1911 uses a linked tilting barrel with less angular displacement and exhibits reduced ejection port blast hazards when suppressed, as a result. It is important to note that 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). The back pressure generated by the Rugged Obsidian 45 silencer on this weapon system is higher than that generated by some other designs (both legacy and modern).
PEW Science Research Note 3: 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 80 ms in Figure 4a) 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 4: Note that the muzzle Suppression Rating of the Rugged Obsidian 45 in its long configuration on the 1911 semiautomatic handgun test host is 49.2 and the shooter’s-ear Suppression Rating is 35.4; which are in 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 reader is encouraged to consult the Hazard Maps at the beginning of this report and in Silencer Hazard Map Brief 8.1.31 to view personnel risk spatially. The signatures measured at the shooter’s ear with the long configuration of the silencer are presented and examined below.
6.234.2.2 SOUND SIGNATURES AT SHOOTER’S EAR
Real sound pressure histories from the same 6-shot test of the Rugged Obsidian 45 in its long configuration on the Remington 1911 R1 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 6. The primary sound signature history is shown in Figure 6a. A zoomed-in timescale is displayed in Figure 6b, in the region of peak sound pressure for Shot 1, Shot 2, and Shot 5. The real sound impulse (momentum transfer potential) histories at the ear from the same 6-shot test are shown in Figure 7. Again, full and short timescales are shown.
Figure 6a. Rugged Obsidian 45 (Long Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Ear Sound Pressure Signature
Figure 6b. Rugged Obsidian 45 (Long Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Ear Sound Pressure Signature, Short Time Window
Figure 7a. Rugged Obsidian 45 (Long Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Ear Sound Impulse Signature
Figure 7b. Rugged Obsidian 45 (Long Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Ear Sound Impulse Signature Peaks
The two primary differences between the operator signatures generated by the AAC Ti-RANT 45 and the long Rugged Obsidian 45 are the amplitude and duration of ejection port blast loads and the latent mechanical shock. These phenomena are related, as back pressure is shown to potentially increase through the shot string with the Obsidian 45 and latent shock loads begin to increase in amplitude in both pressure space and impulse space. It is possible this is due to silencer heating reducing the efficiency gas expansion; the design of the Obsidian series has no ancillary off-axis gas paths to relieve stagnation. Shot 5 is included in the above short time window plots to illustrate this behavior. Interestingly, this also occurs during Shot 5 in the short configuration test as shown in Figure 11b in Section 6.234.3.2 of this report. Therefore, the possibility of Shot 5 and Shot 6 behavior being ammunition related is very unlikely). This also demonstrates that low early time flow rate (high early time back pressure driven by lack of clearing / venting) drives this behavior, as the late time flow rate of the short configuration is higher than that of the long configuration. Finally, the impulse plots in Figure 7 show a combined accumulation of ejection port and muzzle blast loads that manifested differently in the previous AAC Ti-RANT 45 testing. Ejection port blast load duration is likely driving these differences.
PEW Science Research Note 5: As previously discussed in the AAC study, the blast signatures measured at the operator’s head with a suppressed full-size 1911 are somewhat different than the previously examined HK MK23 and HK USP45 Tactical weapon signatures. Breech blast in early time is significantly reduced in pressure space (Figure 6) and momentum accumulation from that event with the Ti-RANT 45 was approximately half of that from a MK23 with KAC silencer. It is likely that the smaller displacement linked action of the 1911 provides superior lock time for suppressed use than the modified tilting-barrel Browning actions used in the HK pistols. With the Obsidian 45, the ejection port blast increases the peak impulse accumulation back to levels similar to the legacy KAC silencer. In summary, the back pressure of the Obsidian 45 greatly handicaps the relative performance of the silencer.
Note that the consistency of the signature, from shot to shot, is high. Other than FRP divergence during primary blast (Fig. 7b, 31.2 ms), blast momentum is controlled throughout the shot string.
The short configuration of the Obsidian 45 is evaluated below on the same weapon system with the same ammunition.
6.234.3 Rugged Obsidian 45 (Short Configuration) 1911 Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Rugged Obsidian 45 in its short configuration tested on the Remington 1911 R1 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 2. Rugged Obsidian 45 (Short Configuration) Subsonic .45 ACP 1911 Sound Metric Summary
6.234.3.1 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 45 in its short configuration tested on the Remington 1911 R1 are shown in Figure 8a. The sound signatures of Shot 1 and Shot 2 are shown in Figure 8b, in early time. The real sound impulse (momentum transfer potential) histories from the same 6-shot test are shown in Figure 9a. In Figure 9b, a shorter timescale is shown comparing the impulse of Shots 1 through 3.
Fig 8a. Rugged Obsidian 45 (Short Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 8b. Rugged Obsidian 45 (Short Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Muzzle Sound Pressure Signature, Short Time Window
Fig 9a. Rugged Obsidian 45 (Short Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Muzzle Sound Impulse Signature
Fig 9b. Rugged Obsidian 45 (Short Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Muzzle Sound Impulse Signature, Short Time Window
The Rugged Obsidian 45 is a modular silencer in that the front section can be removed. This reduces the total baffle count to 8, from the original 12. The proximal end of the silencer, and thus the early time flow rate, remains identical in both configurations. However, the late time flow rate increases significantly when the front section is removed. This behavior is quantified directly by the calculated drop in the Omega Metric, derived from the rate of impulse accumulation in Figure 9a compared with that in Figure 5a. Blast momentum escaping from the silencer occurs faster when in the short configuration, compared with that of the long configuration.
PEW Science Research Note 6: As described above, the back pressure of the Obsidian 45 in its short configuration is identical to the long configuration in early time, but lower in late time. This results in somewhat lower ejection port blast to the weapon operator with the short configuration of the silencer. However, because of the degree of increased muzzle blast severity and muzzle blast propagation to the operator’s location, the net operator protection drops. This phenomenon is visually presented in the accompanying Silencer Hazard Maps at the beginning of this report and in Silencer Hazard Map Brief 8.1.31.
Performance traits of the Rugged Obsidian 45 in its short configuration displayed in the above test data are:
Higher amplitude muzzle blast with faster blowdown (Fig. 8a).
Similar first precursor with significantly higher amplitude coupled jetting (Fig. 8b).
Faster impulse accumulation (Fig. 9a) with relatively consistent post-FRP momentum control (Fig. 9b).
Observations (1) and (2) are typical of truncated length silencers when compared to their full length counterparts. Observation (3) is also typical, though the consistent post-FRP momentum control is a notable performance trait of this silencer. Though muzzle blast intensity is certainly severe with the short configuration of the Obsidian 45, it is also consistent throughout the shot string.
PEW Science Research Note 7: The muzzle Suppression Rating of the Rugged Obsidian 45, in the free field, changes from 49.2 to 32.4 when changing from its long to short configuration. This performance change, spanning more than a full Suppression Rating Performance Category, indicates that the hazard adjacent to the weapon system when the two different configurations of the silencer are used is significantly different. However, the operator hazard reduction with the short configuration of the Obsidian 45 does not drop as significantly. This is due to the aforementioned back pressure reduction. 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. PEW Science strongly encourages examination of these performance factors in Section 6.234.3.2, below.
6.234.3.2 SOUND SIGNATURES AT SHOOTER’S EAR
Real sound pressure histories from the same 6-shot test of the Rugged Obsidian 45 in its short configuration on the Remington 1911 R1 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 10. The primary sound signature history is shown in Figure 10a. A zoomed-in timescale is displayed in Figure 6b, in the region of peak sound pressure for Shot 1, Shot 2, and Shot 5. The real sound impulse (momentum transfer potential) histories at the ear from the same 6-shot test are shown in Figure 11. Again, full and short timescales are shown.
Fig 10a. Rugged Obsidian 45 (Short Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Ear Sound Pressure Signature
Fig 10b. Rugged Obsidian 45 (Short Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Ear Sound Pressure Signature, Short Time Window
Fig 11a. Rugged Obsidian 45 (Short Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Ear Sound Impulse Signature
Fig 11b. Rugged Obsidian 45 (Short Configuration) Subsonic .45 ACP 1911 Semiautomatic Pistol Ear Sound Impulse Signature, Short Time Window
Interestingly, the shape of the measured blast impulse traces with the short configuration of the Obsidian 45 begin to more closely resemble those of the Ti-RANT 45 in that the duration of ejection port blast is reduced. This somewhat decouples latent mechanical shock signatures. Due to the higher gross amplitude of the blast overpressure throughout the risk field, the Obsidian 45 still produces a lower Suppression Rating. Nonetheless, the reduced back pressure of the short configuration of the silencer is at least apparent in the measured test data.
An interesting point of comparison is that the operator protection with the short configuration of the Obsidian 45 on the 1911 is somewhat similar to the operator protection with the short configuration of the Obsidian 9 on the HK P30L. However, when examining the blast load signatures, they are extremely different (ref. Fig. 8a in 6.172.2.2 compared with Fig. 11a, above). The blast input pressure differences of the two cartridges and the bore diameter differences of the two silencers are responsible for these changes, along with the lock time mechanics of the host weapon operating systems.
PEW Science Research Note 8: As discussed in the preceding section of this report, 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 or at least not change as much as the Suppression Rating adjacent to the muzzle. 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 45 in its short configuration is likely considered “louder” than in its long 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 tree line.
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.
6.234.4 Suppression Rating Comparisons (Subsonic .45 ACP from the 1911, HK MK23, and USP 45 Tactical)
Figure 12 again presents a comparison of the calculated PEW Science Suppression Ratings of the Rugged Obsidian 45 in both its long and short configurations and the AAC Ti-RANT 45 on the full-size .45ACP 1911, along with the KAC MOD.MK23/USP and B&T Impulse-IIA SD Mk23 Rev. 03 silencers on both full-size HK MK23 and USP45 Tactical using full power subsonic Speer Lawman 230gr .45 ACP ammunition. Unsuppressed system risk metrics are also presented.
Fig 12. Suppression Rating Comparisons of Rugged Obsidian 45 and AAC Ti-RANT 45 on the Remington 1911 R1 and KAC MOD.MK23/USP and B&T Impulse-IIA SD Mk23 Rev. 03 silencers on the HK MK23 and USP45 Tactical full-size semiautomatic pistols Using PEW-SOFT Test Data and PEW Science Analysis
From the above performance comparisons, the following gross conclusions can be made:
The Rugged Obsidian 45 produces the highest pure muzzle suppression performance of the group, when used in its long configuration. However, its significant back pressure results in an operator (shooter’s ear) Suppression Rating almost a full category lower than that of the legacy AAC Ti-RANT 45, and on par with that of the legacy KAC silencer on the MK23 and USP. This is a significant performance conclusion, as the Rugged Obsidian 45 is the most modern silencer of the group.
When fielded in the short configuration, the Rugged Obsidian 45 produces a risk field adjacent to the muzzle on the 1911 that is similar to that of the legacy KAC silencer on the MK23. However, its operator protection is again lacking due to low early time flow rate combined with more severe muzzle blast, and its shooter’s ear Suppression Rating drops to a range comparable to that of the legacy B&T silencer on the USP. It is important to note that the short configuration of the Rugged Obsidian 45 is a full inch shorter than the B&T silencer. Note that the long configuration of the Obsidian 45 has a length comparable to that of the AAC Ti-RANT 45.
As previously reported, the AAC Ti-RANT 45 produces exceptionally higher performance than both the KAC and B&T silencers and its operator protection is also significantly more robust than that of the Rugged Obsidian 45, regardless of Obsidian configuration.
The KAC MOD.MK23/USP silencer, and its requisite inertial-decoupling piston assemblies, provide scalable signature suppression and personnel hazard reduction performance on the two HK combat handgun host weapons. The KAC system performance is more robust than the B&T system performance.
The 1911 and HK MK23 system signatures may be suppressed to a greater degree than the HK USP45 Tactical system signature. This is a function of the longer 1911 and MK23 barrels generating lower muzzle blast pressure input into the silencer(s), as well as system lock time mechanics and dynamics.
The 1911 system lock time and barrel rifling differs from the two HK systems. This changes unsuppressed and suppressed hazards by varying ejection port blast timing and muzzle blast precursor development. Nonetheless, unsuppressed blast loads from all three weapon systems are exceedingly hazardous to personnel in the near field. Silencer use is recommended not only to minimize operational signature, but to reduce damage to the unprotected human ear. Unsuppressed blast loads from the three weapon systems were presented and examined in Report 6.227.
The Rugged Obsidian 45 is marketed on the Rugged Suppressors website as “the quietest 45 suppressor on the market” as of the date of this report publication. As the PEW Science Silencer Sound Standard .45ACP research pedigree grows, further performance comparison cases will be available. Currently, the Obsidian 45 is shown to nominally exceed the pure muzzle suppression performance of the legacy AAC Ti-RANT 45 on the 1911 test host weapon with full power .45ACP ammunition. However, it is important to note that as discussed in conclusion (1) above, the operator protection with the Obsidian 45 is significantly lower than with the Ti-RANT 45 due to high back pressure. As a result of this performance reality, the shooter’s ear Suppression Rating is much lower and that drives the Composite Suppression Rating of the long configuration of the Rugged Obsidian 45 nominally lower than that of the AAC Ti-RANT 45. This indicates that when considering the actual risk field to personnel (both operators and bystanders), objective testing and analysis indicates the Obsidian 45 marketing statement to be somewhat spurious. At the very least, qualifying the statement with “pure muzzle suppression” or “system dependent” performance would be prudent.
PEW Science Research Note 9: 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 blast and muzzle blast. When the silencer’s endcap is in closer proximity to the shooter, the severity is increased. The coalescing of the ejection port blast 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.
6.234.5 Review Summary: Rugged Obsidian 45 on the 1911 Full-Size .45ACP Semiautomatic Pistol
When paired with the 1911 full-size semiautomatic pistol and fired with Speer Lawman 230gr ammunition, the Rugged Obsidian 45 in its long configuration achieved a Suppression Rating™ of 49.5 in PEW Science testing. The short configuration of the Obsidian 45 achieved a Suppression Rating of 34.7 with the same weapon and ammunition.
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 45 is a full size modular 45 caliber pistol silencer intended for multiple uses. In semiautomatic handgun applications, it shows versatility in that it exhibits high performance when suppressing both full-size .45ACP and 9mm handguns in its long configuration. The silencer performance decreases when used in its short configuration. The back pressure of the Rugged Obsidian series of silencers is relatively high; users will experience increased ejection port blast overpressure exposure when using these silencers compared with some more advanced designs.
The baffle geometries of the Obsidian series are characterized by curved and stepped cones with single mill cuts; derivatives of the legacy SWR Omega baffles, without coaxial or annular vent structures. Original Omega baffle technology evaluation is documented in Report 6.8 with the SWR Trident-9 silencer, produced between 2005 and 2011. Like all Omega baffle and simple curved cone baffle derivatives, significant back pressure is produced. In addition to gross geometric factors, initial blast load expansion, clearing, and venting in the proximal end of the silencer influences early time back pressure, thereby significantly influencing operator risk on semiautomatic combat handguns.
The Rugged Obsidian 45 produces the highest pure muzzle suppression performance of the limited group of silencers summarized in this report, when used in its long configuration. However, its significant back pressure results in an operator (shooter’s ear) Suppression Rating almost a full category lower than that of the legacy AAC Ti-RANT 45, and on par with that of the legacy KAC silencer on the MK23 and USP. This is a significant performance conclusion, as the Rugged Obsidian 45 is the most modern silencer of the group.
When fielded in the short configuration, the Rugged Obsidian 45 produces a risk field adjacent to the muzzle on the 1911 that is similar to that of the legacy KAC silencer on the MK23. However, its operator protection is again lacking due to low early time flow rate combined with more severe muzzle blast, and its shooter’s ear Suppression Rating drops to a range comparable to that of the legacy B&T silencer on the USP. It is important to note that the short configuration of the Rugged Obsidian 45 is a full inch shorter than the B&T silencer. Note that the long configuration of the Obsidian 45 has a length comparable to that of the AAC Ti-RANT 45.
From the 2020 9mm pistol testing evaluation of the silencer in Report 6.7:
Although a 9mm end-cap (shared with its “sister” silencer, the Obsidian 9) may be used with the Obsidian 45, PEW Science does not recommend doing so in the long configuration. Due to possible alignment, tolerance-stacking, and internal ballistics anomalies, users may experience end-cap strikes when using the 9mm end-cap on the Obsidian 45 in the long configuration on 9mm hosts. This has occurred during PEW Science testing of the silencer on both modified Browning tilting-barrel action pistols (such as the HK P30L and Glock 19) and on fixed-barrel 300BLK weapons with the 3-lug mount. PEW Science testing of the Obsidian 45 in the short configuration with the 9mm end-cap has not resulted in end-cap strikes. The Obsidian 45 tested by PEW Science may have a specific issue that may be able to be rectified, but the aforementioned conclusions stand. This highlights one of the potential drawbacks of modular silencers. However, it is important to note that the Obsidian 45 in its long configuration with the .45 end-cap on the HK P30L 9mm host still exhibits high performance.
The internal piston assembly functions reliably and possesses physical features that may limit blow-back of particulate matter noted by the shooter on semiautomatic pistol hosts; evaluation of those features is a subject of continued research interest. The silencer does possess First Round Pop (FRP) which manifests itself in not only measured sound pressure and impulse, but in calculated physical human ear response. (The FRP is analytically predicted to be noticeable to the unprotected human ear and this conclusion agrees with PEW Science anecdotal observation. However, PEW Science testing and analysis of the Obsidian 45 indicates that the FRP observations by the shooter and bystanders may differ when the silencer is used in the long configuration.)
The Obsidian 45 is not relatively heavy or long for a full-size 45 caliber pistol silencer in today’s market. This indicates a degree of design efficiency, as the silencer possesses traits that result in weight increases (e.g. modularity and a fully stainless steel baffle stack). However, when compared to 9mm pistol silencers, it is heavier and longer. That type of comparison may be relevant for users who wish to use the Obsidian 45 on multiple calibers.
The construction of the Obsidian 45 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 45 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 and it is also rated by the manufacturer for use on higher energy cartridges, including .450 Bushmaster, .44 magnum, and subsonic .458 SOCOM on 16-inch barrels. 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 45 performance metrics depend upon suppressing the venerable and historic full-size 1911 combat handgun firing the full-power .45ACP subsonic centerfire pistol cartridge. 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.
