SSS.6.62 - SilencerCo Omega 9K and the Q mini FIX 300 BLK Subsonic (Free Version)
/SilencerCo Omega 9K on a Q mini FIX 300 BLK with 8-in Barrel
The Omega 9K is manufactured by SilencerCo. It is a 9mm centerfire pistol silencer, intended to suppress many cartridges with projectiles appropriately sized to travel through the bore, including subsonic and supersonic 300 BLK from barrels as short as 8 inches. It has a 1.5-inch diameter and is 4.6 inches in length. The silencer mounts to host firearms with a variety of mounts that are compatible with the so-called “alpha” 1.125”-25tpi system; the user may choose from various SilencerCo mounting accessories. The silencer is tubeless and constructed of welded heat treated stainless steel baffles. As tested, the silencer weighs 6.6 ounces and the direct thread mount weighs 1 ounce, for a total system weight of 7.6 ounces. The Omega 9K can be obtained from Silencer Shop.
This review contains single-test results using the Omega 9K mounted with the direct thread mount on the Q mini FIX bolt action pistol, chambered in 300 BLK with an 8-inch barrel. Discreet Ballistics 190gr ammunition was used in the test.
- Section 6.62.1 contains the Omega 9K test results and analysis.
- Section 6.62.2 contains Suppression Rating comparisons with selected .30 rifle silencers in the subsonic flow regime.
- Section 6.62.3 contains the review summary and PEW Science opinions.
Summary: When paired with the Q mini FIX 8” 300 BLK and fired with Discreet Ballistics 190gr Subsonic Target ammunition, the SilencerCo Omega 9K with the direct thread mount achieved a Suppression Rating™ of 37.4 in PEW Science testing.
Relative Suppression Rating Performance is Summarized in SSS.7 - PEW Science Rankings
6.62.1 SilencerCo Omega 9K Sound Signature Test Results
A summary of the principle Silencer Sound Standard performance metrics of the SilencerCo Omega 9K is shown in Table 1. The data acquired 1.0 m (39.4 in) left of the muzzle is available for viewing to all. The data acquired 0.15 m (6 in) right of the shooter’s ear is only available to membership supporters of PEW Science and the Silencer Sound Standard. You can support PEW Science testing, research, and development with a membership, here. State-of-the-art firearm sound signature testing and research conducted by PEW Science is supported by readers like you.
Table 1. SilencerCo Omega 9K Sound Metric Summary
6.62.1.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 5-shot test acquired with PEW-SOFT™ are shown below. The waveforms are not averaged, decimated, or filtered. The data acquisition rate used in all PEW Science testing is 1.0 MS/s (1 MHz). The peaks, shape, and time phasing (when the peaks occur in relation to absolute time and to each other) of these raw waveforms are the most accurate of any firearm silencer testing publicly available. PEW-SOFT data is acquired by PEW Science independent testing; the industry leader in silencer sound research. For more information, please consult the Silencer Sound Standard, here.
Figure 1 shows a 2.4-millisecond long sequence of events during the first test shot with the SilencerCo Omega 9K, as measured 1.0 m left of the muzzle. There are four significant events shown:
During combustion within the weapon system, a 124.7 dB peak is measured.
The initial jetting from precursor flow is suppressed and the peak amplitude is measured to be 128.1 dB.
The first major jet builds to a measured amplitude of 149.8 dB.
The maximum pressure amplitude of the primary jet is measured to be 150.4 dB.
This is a typical sequence observed when firing subsonic 300 BLK ammunition from a bolt-action weapon system with an attached silencer that exhibits relatively low flow restriction (relatively low back pressure); internal silencer design can significantly influence the measured timing and pressure amplitudes.
Fig. 1 Early-Time Shot History, SilencerCo Omega 9K Bolt Action 300 BLK Muzzle Sound Pressure Signature, 28-AUG-2021
The back pressure generated by the SilencerCo Omega 9K is lower than that generated by typical 30 caliber silencers on the 300 BLK platform due to significant over-bore. The 9mm bore in the six baffles of the Omega 9K allows for significant early-time flow (Feature 3 in Figure 1) additionally characterized by a significant early-time positive phase duration until approximately 30.4 ms. This is in contrast to the behavior of a silencer with significantly restricted flow on the platform, such as the Surefire SOCOM300-SPS (Review 6.57). Due to this higher flow rate from significant over-bore, the Omega 9K possesses a significantly lower Suppression Rating with the subsonic 300BLK cartridge than many dedicated 30 caliber silencers on this weapon system. It should be noted, however, that the Omega 9K is only 4.6 inches long, yet it approaches the muzzle Suppression Rating of the Surefire SOCOM762-RC2 (Review 6.46) on the same platform. The SOCOM762-RC2 possesses a high flow rate, in accordance with the PEW Science Omega Metric (Public Research Supplement 6.40). The significantly higher at-ear Suppression Rating of the SOCOM762-RC2 over that of the Omega 9K is influenced by the silencer’s length and the distance from the endcap orifice to the shooter’s ear. Although it possesses a high flow rate for the cartridge, the Omega 9K surpasses the subsonic 300 BLK Suppression Performance of the OSS HX-QD 762 (Review 6.45); a silencer with an extremely high flow rate.
The primary sound signature pressure histories for all 5 shots are shown in Figure 2a. A zoomed-in timescale displays the region of peak sound pressure in Figure 2b, for the first three shots. The real sound impulse (momentum transfer potential) histories from the same 5-shot test are shown in Figure 3. Again, full and short timescales are shown.
Fig 2a. SilencerCo Omega 9K Bolt Action 300 BLK Muzzle Sound Pressure Signature, 28-AUG-2021
Fig 2b. SilencerCo Omega 9K Bolt Action 300 BLK Muzzle Sound Pressure Signature, Short Time Window, 28-AUG-2021
Figure 3a. SilencerCo Omega 9K Bolt Action 300 BLK Muzzle Sound Impulse Signature, 28-AUG-2021
Figure 3b. SilencerCo Omega 9K Bolt Action 300 BLK Muzzle Sound Impulse Signature, 28-AUG-2021
The SilencerCo Omega 9K produces significantly perceptible FRP to bystanders on this platform; it is pronounced in both the pressure regime (Figure 2) and the impulse regime (Figure 3). As discussed above, the Omega 9K generates lower back pressure due to significant over-bore and short length, and therefore is less efficient at trapping gas on this platform and containing ancillary combustion during the first shots. This is evident in the significantly steeper initial positive phase impulse slopes displayed in Figure 3 during Shot 1 and Shot 2, as well as in the aforementioned significant initial positive phase pressure duration.
PEW Science Research Note 1: The decrease in back pressure with the Omega 9K and its short length compared with that of many dedicated 30 caliber rifle silencers is significant. Subsonic suppression performance is highly dependent upon back pressure generation; it is the primary mechanism of subsonic sound signature suppression in most small arm weapon system silencers.
PEW Science Research Note 2: Significant silencer over-bore for a given cartridge may manifest similarly across suppressed weapon systems. Note the delay in normalization of the impulse in Figure 3 with the Omega 9K. This erratic impulse amplitude, from shot to shot, is also observed with 30 caliber silencers suppressing the 5.56x45mm NATO cartridge such as the Rugged Razor on the MK18 (Review 6.58) and the Q Trash Panda on the MK18 (Review 6.61). With significant over-bore, suppression efficiency and consistency drops. This is also observed in the subsonic 300 BLK testing of the CGS Hyperion K (Review 6.50); a silencer that is actually over-bored for a 30 caliber round. The Hyperion K exhibits uncharacteristically high subsonic 300 BLK suppression performance for its high flow rate, overall, due to expedient blast chamber venting to its annulus.
As stated above, the FRP of the Omega 9K in the subsonic flow regime is significant. First-round sound signatures always differ from subsequent shots, as the atmosphere within the silencer changes. The FRP phenomenon cannot always be shown by viewing only the peak sound pressure. This is one of the reasons why The Silencer Sound Standard requires examining multiple sound signature metrics.
With subsonic 300 BLK from an 8-inch barrel, the Omega 9K is noticeably louder to bystanders than many other silencers from an 8-in barrel. Direct comparisons with other silencers are provided in Section 6.62.2, below.
6.62.2 Suppression Rating Comparison - Subsonic 300 BLK
The SilencerCo Omega 9K suppressor is intended to be used as a compact pistol silencer with relatively high flow rate (low back pressure; low PEW Science Omega metric) and may possess inefficient sound suppression performance (PEW Science Suppression Rating) with subsonic 300 BLK due to significant over-bore and short length. Figure 6 shows a performance comparison of the eleven .30 rifle silencer configurations tested with the subsonic 300 BLK cartridge shown in public PEW Science testing, to date. Unsuppressed and suppressed Suppression Ratings are shown for both the shooter and bystanders.
Figure 6. Suppression Rating Comparisons Of .30 Rifle Silencers Using PEW-SOFT 300 BLK Subsonic Test Data
The SilencerCo Omega 9K is unable to reach the subsonic 300 BLK sound suppression performance of many compact and midsize .30 silencers on the market. This lower subsonic suppression performance for a compact 9mm pistol silencer like the Omega 9K is a physical consequence of the silencer’s significant over-bore for the cartridge and the short length placing the endcap orifice closer to the shooter’s ear. However, the Omega 9K surpasses the subsonic 300 BLK Suppression Performance of the OSS HX-QD 762 (Review 6.45) at both the muzzle and the shooter’s ear. This is somewhat notable, as the HX-QD 762 is a full size 30 caliber rifle silencer. The OSS silencer has a flow rate that is so high, its performance with subsonic 300 BLK is severely handicapped; the lack of precursor flow suppression, alone, is a significant indicator.
More notable is that the SilencerCo Omega 9K approaches the muzzle Suppression Rating of the Surefire SOCOM762-RC2 (Review 6.46) with subsonic 300 BLK. As previously stated, the significantly higher at-ear Suppression Rating of the SOCOM762-RC2 over that of the Omega 9K is influenced by the silencer’s length and the distance from the endcap orifice to the shooter’s ear.
6.62.4 Review Summary: SilencerCo Omega 9K on a Q mini FIX 300 BLK with 8-in Barrel
When paired with the Q mini FIX 8” 300 BLK and fired with Discreet Ballistics 190gr Subsonic Target ammunition, the SilencerCo Omega 9K with the direct thread mount achieved a Suppression Rating™ of 37.4 in PEW Science testing.
PEW Science Subjective Opinion:
The SilencerCo Omega 9K is a compact 9mm pistol silencer that is relatively versatile in potential application and durable enough for hard use. Although rated for automatic use with both supersonic and subsonic 300 BLK on barrels greater than or equal to 8 inches in length, its sound suppression performance on these platforms may be lower than that of dedicated 30 caliber silencers or longer over-bored 9mm pistol silencers.
The direct thread mount was used in the testing of the Omega 9K on this platform. The silencer also contains an integrated internal “cage” for use with an optional inertial decoupler piston assembly to suppress semiautomatic 9mm handguns. In addition to these mounting schemes, the silencer may be used with 3-lug mounts and other mounting systems that can interface with its rear female threading. These mounting options, along with its welded steel construction, allow for significant versatility.
Despite the silencer’s versatility, users should note that the Omega 9K is not able to be fully disassembled for cleaning; only the mounts can be removed from the welded silencer body. This factor may influence its use on certain cartridges and weapon systems that may induce significant fouling over time. The user is encouraged to follow a maintenance schedule per manufacturer directive.
The Omega 9K is a purpose-built compact pistol silencer. Its utility in application to suppress intermediate rifle cartridges like 300 BLK is noteworthy, but not without performance limitations. The thresholds of suppression performance due to significant over-bore and reduced length in the subsonic flow regime are evident in the presented test data.
In this review, the SilencerCo Omega 9K performance metrics depend upon suppressing a subsonic intermediate rifle cartridge. While the sound signature of such cartridges can be suppressed to levels that may result in the desire of the shooter and bystanders to not wear hearing protection, PEW Science encourages the reader to remain vigilant with regard to all subsonic rifle cartridge suppression claims. The gas volume and combustion products created by firing a subsonic intermediate rifle cartridge such as 300 BLK are still significant; the measured pressure and impulse magnitudes, and their durations, illustrate this fact.
The hearing damage potential of subsonic rifle use is not insignificant. PEW Science encourages the reader to consider the Suppression Rating when deciding on an appropriate silencer and host weapon combination for their desired use.
