SSS.6.198 - Microtech Defense R2K9 and the HK P30L (Free Version)
/Microtech Defense R2K9 on the HK P30L Full-Size Semiautomatic Pistol
The R2K9 is designed and manufactured by Microtech Defense Industries. It is a 9mm centerfire pistol silencer, intended to suppress the 9x19mm cartridge from semiautomatic handguns and submachine guns. The R2K9 is a modular silencer with a 1.38-inch primary diameter, and its long configuration is 8.63 inches in length. In its short configuration, the silencer is 6.44 inches in length. These lengths include the internal inertial-decoupling piston possessing 1/2-28tpi or 13.5x1mm LH threading; both are included with the silencer retail kit. The R2K9 is fully user-serviceable; the silencer kit includes the following:
Two (2) aforementioned pistons
Spare O-rings
End cap / piston retainer cap removal tool
Fixed barrel spacer
2-sided armorers tool
2-piece push rod and guide
Hard case and laminated operator/maintenance manual
Additional pistons are available separately in 5/8-24tpi, 1/2-32tpi, and 1/2-36tpi threading. Users should note that the Microtech Defense R2K9 is not compatible with generic SilencerCo / Rugged / HUXWRX pattern pistons. If the R2K9 is fielded for submachinegun use, the included fixed barrel spacer should be installed in lieu of the piston spring, as is typical for 9mm pistol silencers possessing inertial decoupling mechanisms. The R2K9 tubes, baffles, and end cap are machined from 6AL-4V titanium, whereas the pistons are stainless steel. With the piston and spring installed, the silencer weighs 11.7 ounces in the long configuration and 9.3 ounces in the short configuration, as tested. The Microtech Defense R2K9 is still being manufactured as of the date of this report publication and it can be obtained through dealers such as Capitol Armory.
This Sound Signature Review contains test results and analysis for two silencer configurations in two tests. Test data was generated using the Microtech Defense R2K9 (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 6.198.1 contains the R2K9 test results and analysis in the long configuration.
Section 6.198.2 contains the R2K9 test results and analysis in the short configuration.
Section 6.198.3 contains Suppression Rating comparisons of the R2K9 with the Dead Air Mojave 9, Rugged Obsidian 9, 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 6.198.4 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 Microtech Defense R2K9 achieved a Suppression Rating™ of 55.4 in PEW Science testing. In its short configuration with the same host weapon and the same ammunition, the R2K9 achieved a Suppression Rating of 50.2. 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.
6.198.1 Microtech Defense R2K9 (Long) Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Microtech Defense R2K9 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. The data acquired 0.15 m (6 in) right of the shooter’s ear is only available to membership supporters of PEW Science and the Silencer Sound Standard. You can support public PEW Science testing, research, and development with a membership, here. State-of-the-art public firearm sound signature testing and research conducted by PEW Science is supported by readers like you.
Table 1. Microtech Defense R2K9 (Long Configuration) Sound Metric Summary
6.198.1.1 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 Microtech Defense R2K9 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 3.
Fig 1a. Microtech Defense R2K9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 1b. Microtech Defense R2K9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Sound Pressure Signature
Figure 2a. Microtech Defense R2K9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
Figure 2b. Microtech Defense R2K9 (Long Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
The Microtech Defense R2K9 is a modular pistol silencer; it may be used in both its long or short configuration, similar to silencers like the Rugged Obsidian 9 (6.172), Obsidian 45 (6.7), the modern AAC Ti-RANT series (6.118), CAT SC (6.162), and Dead Air Mojave 9 (6.177). This section of the report addresses the long configuration performance. The short configuration performance is addressed in Section 6.198.2.
PEW Science Research Note 1 (Physical Characteristics): The Microtech R2K9 is a traditionally machined silencer; its baffles are best described as enhanced K-baffles. There are seven baffles in the long configuration of the silencer; all are identical other than the baffles located at the distal end of each tube section, which have truncated lengths. An important feature of the R2K9 baffles is machined geometry that disrupts clearing of the impinging blast loads to generate additional turbulence. It is through these features on the reflected face of each baffle that the system has increased heat transfer efficiency and achieves relatively high performance. It is also important to note that the primary tube is fitted with a perforated piston cage; that is the extent of early venting geometry in the silencer. Therefore, the Microtech Defense R2K9 is classified as a traditional baffle silencer in the research taxonomy; it is not a hybrid design.
Additional internal geometric features of note include the piston vent and tooth geometry that differ from some common geometries in the current market, with a significant number of indexing positions available to the user. Finally, the included fixed barrel spacer is perforated, which is important for adequate early-time flow in this type of design. Most properly designed fixed barrel spacers have similar or equivalent radial vent areas.
Regarding physical assembly, the baffle stack in each module (K unit and Accessory Module) accept baffle retainers at the distal end. These threaded retainer plates capture the baffles within the tube and place them in compression, preventing longitudinal and radial displacement. The retainers are independent of the removable end cap assembly. O-ring seals fit into a recess on the distal end of each truncated baffle, as well as between the modules, between the end cap and modules, and between the piston retainer cap and K unit module. O-rings are maintenance items to be lubricated upon frequent disassembly and spare O-rings are included.
PEW Science Research Note 2: The Microtech Defense R2K9 was released to the market in approximately the year 2020 timeframe and demonstrates performance competitive not only with silencers that proliferated during that timeframe, but also relative to several silencers in the current market, five years later. The above measured signatures from this test of the long configuration of the R2K9 display the following attributes:
Relatively low free field blast pressure amplitude (Fig. 1a).
Noticeable first-round-pop (FRP) divergence in early-time, in both pressure space (Fig. 1b) and impulse space (Fig. 2).
Relatively consistent post-FRP blast impulse accumulation (Fig. 2b).
It interesting to note that the alternating K-baffle vents in the stack (each baffle in the array is oriented at 180-degree radial offset to its neighbor), combined with the machined features on each baffle reflected face and piston vent geometry, only somewhat reduce FRP propagation severity when compared to some other high performance designs. While the FRP suppression performance of the R2K9 is not low (it is somewhat better than the long configuration of the AAC Ti-RANT 9M-HD (6.118); the latest Ti-RANT 9 variant), it is not as advanced in FRP control as the original AAC Ti-RANT 9 or legacy Ti-RANT 9M (historical note: all Ti-RANT variants utilize K-baffles). The Microtech R2K9 in this configuration is also longer than those silencers. FRP severity in this configuration, with full power ammunition as tested, is approximately 49% more severe to bystanders than subsequent shots, on average. This is not extreme for a silencer of this generation, nor is it when compared to several modern models. Again, these conclusions are derived from testing with full power subsonic ammunition, as is used in all of the displayed test data for 9mm pistol silencers evaluated in the Silencer Sound Standard. Use of underpowered ammunition may or may not result in user experience deviations from these conclusions.
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). Note, again, these comparisons are 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. Another interesting case study is that of the Dead Air Mojave 9 mentioned earlier in this report. The FRP suppression performance of the Mojave 9 is reduced despite its annular vent paths. It is postulated that the relatively simplistic (but effective) method the Mojave 9 employs to increase early-time flow rate also may exacerbate FRP. Research is ongoing.
PEW Science Research Note 3: As the Microtech Defense R2K9 is not a hybrid design, it is somewhat difficult for it to achieve a high early-time flow rate (low early time back pressure) and maintain its holistic signature suppression performance to bystanders. Given the technology in use at the time of its introduction, this is somewhat expected. Nonetheless, the system still offers relatively competitive operator hazard reduction, as quantified by its shooter’s ear (operator) Suppression Rating. Shooter’s ear signature analysis is provided in the full Member Version of this report.
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 known traditional combat handguns using a modified Browning tilting-barrel action exhibit lock times unfavorable to significant 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).
The short configuration test results and analysis of the Microtech R2K9 are presented in Section 6.198.2.
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 73 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 Microtech Defense R2K9 in its long configuration used on the full-size HK P30L semiautomatic handgun test host is 55.1 and the shooter’s-ear Suppression Rating is 41.2; 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 performance of the Microtech R2K9 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. This is demonstrated in the test summarized in the following section.
6.198.2 Microtech Defense R2K9 (Short) Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Microtech Defense R2K9 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 6.198.1, the data acquired 0.15 m (6 in) right of the shooter’s ear is only available to membership supporters of PEW Science and the Silencer Sound Standard. You can support public PEW Science testing, research, and development with a membership, here. State-of-the-art public firearm sound signature testing and research conducted by PEW Science is supported by readers like you.
Table 2. Microtech Defense R2K9 (Short Configuration) Sound Metric Summary
6.198.2.1 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 Microtech Defense R2K9 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. Microtech Defense R2K9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 5b. Microtech Defense R2K9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Pressure Signature
Fig 6a. Microtech Defense R2K9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
Fig 6b. Microtech Defense R2K9 (Short Configuration) subsonic 9x19mm HK P30L Semiautomatic Pistol Muzzle Sound Impulse Signature
Note that both the “long” and “short” configurations of the silencer can be used without the end cap installed, due to the use of baffle retainer plates. However, the manufacturer recommends the end cap be installed to protect the internal tube threads and to assure optimal suppression performance. The test of the short configuration was conducted with the end cap installed, as directed.
The removal of the distal section of the Microtech R2K9 to adapt it from its long to short configuration does significantly change its signature on the standard HK P30L test host, but it is important to note that the short configuration of this silencer is 6.4 inches long. That is longer than typical for the truncated length (short) configuration of a 9mm pistol silencer (only two baffles are removed to achieve this configuration). As such, the signature differentials observed and listed below should be considered in that context:
Higher gross free field blast pressure amplitude (Fig. 5a).
More expedient blowdown and subsequent higher amplitude and decoupled ground reflection (Fig. 5a).
Significant negative phase during initial coupled jetting, indicating a stronger momentum profile (Fig. 5b).
More severe primary jetting after (3) (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).
Again, the above differences are relatively typical when removing a section from the distal end of a silencer, but they don’t present as significantly as if there was a substantial section removed.
PEW Science Research Note 8: The FRP differential from the Microtech R2K9 is actually now somewhat more severe in the short configuration than it was in the long configuration, which stands to reason given its mechanism(s) of suppression throughout the stack. Whereas the long configuration had an approximately 49% increase bystander hazard during FRP, on average, the short configuration has an approximately 79% increase in bystander hazard during FRP, on average. Again, the quenching of ancillary FRP combustion is limited to the aforementioned mechanisms described in Research Notes 1 and 2 of this report; there are no hybrid design features to enhance this area of performance.
To put the length of the “short” configuration of the Microtech R2K9 in further context, the Dead Air Mojave 9 is 5.9 inches long in its short configuration, the Obsidian 9 is 5.1 inches long in its short configuration, 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 short configuration of the R2K9 is the longest of the group, and is close to the length of the Inert Haze Ti-P (6.145), and slightly shorter than the Resilient Suppressors RSP (6.87). The Microtech R2K9 outperforms those two silencers in muzzle suppression while also exceeding the muzzle suppression performance of all shorter silencers on this host weapon. For example, the short configuration of the R2K9 significantly outperforms the Omega 9K in hazard reduction. The short CAT SC significantly outperforms the Microtech R2K9 in free field operator hazard reduction, but the short R2K9 outperforms the short CAT SC in bystander (muzzle) hazard reduction.
PEW Science Research Note 9: The muzzle Suppression Rating of the Microtech R2K9, in the free field, changes from 55.1 to 49.0 when changing from its long to short configuration. This performance change only spans half a Suppression Rating Performance Category, and indicates that the hazard adjacent to the weapon system when the two different configurations of the silencer are used are different, but not significantly as is the case with some other long/short silencer variants. Interestingly (and expected) is that the operator hazard reduction with the short configuration of the R2K9 is almost identical to that of the long configuration. 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 highly encourages examination of the full member version of this report for elaboration on these performance facts.
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 Microtech Defense R2K9.
The signatures measured at the shooter’s ear with the short configuration of the silencer are presented and examined in the full Member Version of this report. The following section presents overall comparisons of centerfire pistol silencer configurations on the HK P30L semiautomatic pistol.
6.198.3 Suppression Rating Comparison (Subsonic 9x19mm from the HK P30L)
Figure 9 presents a comparison of the PEW Science Suppression Ratings of the Microtech Defense R2K9 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 Microtech Defense R2K9 in both long and short configurations with the Dead Air Mojave 9, Rugged Obsidian 9, 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
As previously discussed, the Microtech Defense R2K9 is a traditionally machined modular silencer utilizing highly optimized and refined K-baffles; both its long and short configurations are longer than typical for this class of silencers, and that does present some interesting performance potentials. When in its long configuration (8.63-in), the R2K9 is competitive in gross suppression performance with the majority of legacy designs. In its shorter configuration (6.44-in), the R2K9 possesses higher gross suppression performance than any other “short” silencer, though it is also longer than those silencers in that configuration.
R2K9 Long Configuration Performance Notes: With regard to the performance of the long configuration of the Microtech R2K9, as previously discussed, there are FRP factors of which the user should be aware. While the FRP suppression performance of the R2K9 is not low (it is somewhat better than the long configuration of the AAC Ti-RANT 9M-HD (6.118); the latest Ti-RANT 9 variant), it is not as advanced in FRP control as the original AAC Ti-RANT 9 or legacy Ti-RANT 9M (historical note: all Ti-RANT variants utilize K-baffles). The Microtech R2K9 in this configuration is also longer than those silencers. FRP severity in this configuration, with full power ammunition as tested, is approximately 49% more severe to bystanders than subsequent shots, on average. This is not extreme for a silencer of this generation. Again, these conclusions are derived from testing with full power subsonic ammunition, as is used in all of the displayed test data for 9mm pistol silencers evaluated in the Silencer Sound Standard. Use of underpowered ammunition may or may not result in user experience deviations from these conclusions.
R2K9 Short Configuration Performance Notes: To put the length of the “short” configuration of the Microtech R2K9 in further context, the Dead Air Mojave 9 (6.177) is 5.9 inches long in its short configuration, the Rugged Obsidian 9 (6.172) is 5.1 inches long in its short configuration, 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 short configuration of the R2K9 is the longest of the group, and is close to the length of the Inert Haze Ti-P (6.145), and slightly shorter than the Resilient Suppressors RSP (6.87). The Microtech R2K9 outperforms those two silencers in muzzle suppression while also exceeding the muzzle suppression performance of all shorter silencers on this host weapon. For example, the short configuration of the R2K9 significantly outperforms the Omega 9K in hazard reduction. The short CAT SC significantly outperforms the Microtech R2K9 in free field operator hazard reduction, but the short R2K9 outperforms the short CAT SC in bystander (muzzle) hazard reduction.
PEW Science Research Note 12: Further examination of Figure 9 highlights an emerging trend in centerfire combat handgun silencer performance research. Hybrid designs, as classified in the PEW Science research taxonomy, are demonstrating the most significant performance potentials. While more primitive k-baffle, curved-cone baffle, and similar designs are capable of significant signature suppression performance, balanced protection for both the operator and bystanders is demonstrated to have the greatest chance of success with more modern solutions. The hybrid design taxonomy was recently listed and described in Research Note 4 of Report 6.196. PEW Science encourages the reader to review the requisite technologies, featured silencer models, and their performance potentials.
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 13: 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.
6.198.4 Review Summary: Microtech Defense R2K9 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 Microtech Defense R2K9 achieved a Suppression Rating™ of 55.4 in PEW Science testing. In its short configuration with the same host weapon and the same ammunition, the R2K9 achieved a Suppression Rating of 50.2.
As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.
PEW Science Laboratory Staff Opinion:
The Microtech Defense R2K9 is a high performance modular centerfire pistol silencer with lengths in each configuration that are somewhat longer than typical. These lengths allow for interesting performance potentials, given that the silencer uses optimized legacy K-baffle technology. In the short configuration, the silencer is shorter than most full size pistol silencers but achieves performance higher than many “short configurations.” Users may find this balance of size and performance attractive. The R2K9 is user-serviceable and the retail package includes a plethora of accessory and maintenance components not typically found with competing models. Released to the market in the year 2020 timeframe, the Microtech R2K9 still brings competitive performance five years later, in a relatively lightweight envelope.
The Microtech R2K9 is a traditionally machined silencer; its baffles are best described as enhanced K-baffles. There are seven baffles in the long configuration of the silencer; all are identical other than the baffles located at the distal end of each tube section, which have truncated lengths. An important feature of the R2K9 baffles is machined geometry that disrupts clearing of the impinging blast loads to generate additional turbulence. It is through these features on the reflected face of each baffle that the system has increased heat transfer efficiency and achieves relatively high performance. When the silencer is assembled in the “short” configuration, only two baffles are removed.
As the Microtech Defense R2K9 is not a hybrid design, it is somewhat difficult for it to achieve a high early-time flow rate (low early time back pressure) and maintain its holistic signature suppression performance to bystanders. Given the technology in use at the time of its introduction, this is somewhat expected. Nonetheless, the system still offers relatively competitive operator hazard reduction, as quantified by its shooter’s ear (operator) Suppression Rating.
The R2K9 still exhibits high overall performance in its “short” configuration. To put the length of the “short” configuration of the silencer in further context, the Dead Air Mojave 9 is 5.9 inches long in its short configuration, the Obsidian 9 is 5.1 inches long in its short configuration, the SilencerCo Omega 9K is 4.9 inches long, the HUXWRX CASH 9K is 5.4 inches long, and the short configuration of the CAT SC is 5.5 inches long. The short configuration of the R2K9 is the longest of the group, and is close to the length of the Inert Haze Ti-P, and slightly shorter than the Resilient Suppressors RSP. The Microtech R2K9 outperforms those two silencers in muzzle suppression while also exceeding the muzzle suppression performance of all shorter silencers on this host weapon. For example, the short configuration of the R2K9 significantly outperforms the Omega 9K in hazard reduction. The short CAT SC significantly outperforms the Microtech R2K9 in free field operator hazard reduction, but the short R2K9 outperforms the short CAT SC in bystander (muzzle) hazard reduction.
The muzzle Suppression Rating of the Microtech R2K9, in the free field, changes from 55.1 to 49.0 when changing from its long to short configuration. This performance change only spans half a Suppression Rating Performance Category, and indicates that the hazard adjacent to the weapon system when the two different configurations of the silencer are used are different, but not significantly as is the case with some other long/short silencer variants. Interestingly (and expected) is that the operator hazard reduction with the short configuration of the R2K9 is almost identical to that of the long configuration. 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.
The R2K9 retail package includes all necessary accessories and tools for silencer use and maintenance, which is relatively atypical for today’s silencer products. The silencer is fully user—serviceable. Regarding physical assembly, the baffle stack in each module (K unit and Accessory Module) accept baffle retainers at the distal end. These threaded retainer plates capture the baffles within the tube and place them in compression, preventing longitudinal and radial displacement. The retainers are independent of the removable end cap assembly. O-ring seals fit into a recess on the distal end of each truncated baffle, as well as between the modules, between the end cap and modules, and between the piston retainer cap and K unit module. O-rings are maintenance items to be lubricated upon frequent disassembly and spare O-rings are included.
Like many pistol silencers, the Microtech R2K9 is constructed of titanium; firing schedules should be discussed with the manufacturer, as appropriate. Microtech Defense indicates that fully automatic fire with 9mm, .380, and .22LR ammunition is within the design parameters of the system.
Users should note that the Microtech Defense R2K9 is not compatible with generic SilencerCo / Rugged / HUXWRX pattern pistons. If the R2K9 is fielded for submachinegun use, the included fixed barrel spacer should be installed in lieu of the piston spring, as is typical for 9mm pistol silencers possessing inertial decoupling mechanisms.
In this review, the Microtech Defense R2K9 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.
