SSS.6.195 - FOR Systems Monarch Recce and the MK18 5.56x45mm Short Barrel Automatic AR15 Rifle (Free Version)
/FOR Systems Monarch Recce on the MK18 5.56x45mm AR15 with 10.3-in Barrel
The Monarch Recce is designed by Front of Rifle Systems (FOR Systems). It is a compact 223 caliber centerfire rifle silencer, intended to suppress the 5.56x45mm NATO cartridge on semiautomatic and automatic rifles. It has a 1.62-inch diameter and is 4.94 inches in length, without a mount. The user may choose to install third-party adapters compatible with the 1.375”-24tpi system. The total length with the tested mount and flash hider is 5.13 inches. The silencer is monolithic and manufactured from 718 Inconel alloy; titanium model is also available. Both material variants are 3D printed. As tested, the Inconel variant of the silencer weighs 13.4 ounces and the mount and flash hider weigh 3.2 ounces, for a total tested system weight of 16.6 ounces. The Monarch Recce can be obtained from Silencer Shop.
PEW Science is an independent private testing laboratory and also hosts the world’s only independent public suppressed small arms research cooperative. Testing, data analysis, and reporting is generated with funding provided by PEW Science members. Any test data that is generated with any portion of private funding contains this disclosure. The testing and analysis production for this Sound Signature Review was funded in part by PEW Science Project PEW-FOR-113-001-25. Therefore, data pertaining to the Monarch Recce in this Sound Signature Review is published with the express written permission of DB Technologies, LLC.
The testing and analysis presented in this Sound Signature Review is of the FOR Systems Monarch Recce mounted with a Zilch HUB coupler onto a Rearden R2S flash hider on the MK18 Automatic AR15 rifle rifle, chambered in 5.56x45mm NATO with a 10.3-inch barrel. Federal XM193 55gr ammunition was used in the test. The standard PEW Science MK18 test host weapon system is described in Public Research Supplement 6.51.
Section 6.195.1 contains Monarch Recce test results and analysis.
Section 6.195.2 contains overall Suppression Rating comparisons of the FOR Systems Monarch Recce with with dedicated 223 and 30 caliber silencers on the current market, including the Engaged Industries Operator 5.56, Q Southpaw, Centurion Arms Maximus-L, Otter Creek Labs Infinity, PTR VENT Spiritus 556i, LMT AT ION LT, HUXWRX FLOW 556 Ti, Off Grid Operator Ti, Surefire SOCOM556-MINI2, KAC QDC/CRS-PRT, KAC QDC/MCQ-PRT, Surefire SOCOM556-RC3, Otter Creek Labs Polonium-30, AAC M4-2000 Mod 08, PTR VENT 3, SilencerCo Velos LBP, BOSS Guillotine, CAT WB, PWS BDE 556, CAT ODB, Aero Precision Lahar-30L, Lahar-30, HUXWRX FLOW 762 Ti, Maxim Defense DSX, Thunder Beast Dominus, KAC 5.56 QDC, CGS SCI-SIX, Dead Air Nomad-30, YHM Turbo T2, Dead Air Sandman-S, HUXWRX FLOW 556k, Energetic Armament ARX, KAC QDSS-NT4, Rugged Razor556, Otter Creek Labs Polonium and Polonium-K, Surefire SOCOM556-RC2, HUXWRX HX-QD 556 and HX-QD 556k, Q Trash Panda, CGS Helios QD, SilencerCo Saker 556, Rugged Razor762, and others.
Section 6.195.3 contains an article summary and PEW Science laboratory staff opinions.
Summary: When paired with the 10.3-in barrel MK18 and fired with Federal XM193, the FOR Systems Monarch Recce with the Zilch HUB coupler and R2S flash hider mount achieved a composite Suppression Rating™ of 33.3 in PEW Science testing.
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
6.195.1 FOR Systems Monarch Recce Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the FOR Systems Monarch Recce 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. FOR Systems Monarch Recce Sound Metric Summary
6.195.1.1 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, the fire control group positioned to single-shot, and the weapon was fired until the magazine was empty and the bolt locked back on 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 public dataset and bolt-closing signatures. The waveforms are not averaged, decimated, or filtered. The data acquisition rate used in all PEW Science laboratory sound signature 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 laboratory testing; the recognized 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 FOR Systems Monarch Recce with the R2S flash hider mount 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 Shot 1 to that of Shots 2 and 3.
Fig 1a. FOR Systems Monarch Recce 5.56x45mm NATO MK18 Automatic Rifle Muzzle Sound Pressure Signature
Fig 1b. FOR Systems Monarch Recce 5.56x45mm NATO MK18 Automatic Rifle Sound Pressure Signature
Figure 2a. FOR Systems Monarch Recce 5.56x45mm NATO MK18 Automatic Rifle Muzzle Sound Impulse Signature
Figure 2b. FOR Systems Monarch Recce 5.56x45mm NATO MK18 Automatic Rifle Muzzle Sound Impulse Signature
Like the previously evaluated FOR Systems Monarch 762 (6.155), the Monarch Recce is a 3D printed Inconel silencer classified as a hybrid design, incorporating both high flow rate features and conventional geometries to control distal blast propagation while reducing adverse influence on weapon function. For an overview of the three primary classes of rifle silencer designs, the reader is encouraged to review PEW Science Research Supplement 6.169. The Monarch Recce utilizes conventional baffle geometry with a multi-rimmed first reflector (blast baffle) and complete circumferential annular vent passages occupied by spiraled ribbing that terminates in distal vents around the outer circumference of the end plate. This method of annular utilization is becoming increasingly common in modern hybrid designs. In this silencer, the annular paths are less intricate, though still efficiently utilized; downstream geometry is modified as it is a lower pressure stage.
PEW Science Research Note 1: The FOR Systems Monarch Recce is relatively compact; it is only 5.13-in long with the tested mounting system. The following behaviors are observed in the test data presented above:
Relatively expedient blowdown of blast overpressure in the free field, partially revealing ground reflection (Fig. 1a).
Significant first-round-pop (FRP) jet divergence in early time, followed by significantly reduced amplitude (Fig. 1b).
Relatively expedient rise to peak maximum positive phase impulse (Fig. 2a).
Consistent post-FRP momentum accumulation followed by elevated accumulation later in the string (Fig. 2b).
Behaviors (1) and (3) are a consequence of the silencer’s flow rate. The FRP phenomenology in (2) of this particular silencer is also related to its flow rate, as it is a consequence of the way the silencer’s flow rate is achieved (see Research Note 2). Finally, the late-shot severity increase in (4) is due to both lower thermal mass and the flow rate mechanism(s).
PEW Science Research Note 2: Related to the functional design of the first expansion chamber of the Monarch Recce, its FRP, and its mount system(s) compatibility, the tested configuration utilized a “Zilch” HUB mount coupler which places the muzzle orifice relatively close to the blast baffle. In the case of the Recce, primary reduction of blast load impulse accumulation in early time is facilitated by the circumferential annular vent that is around the blast baffle throat. As such, the Recce silencer does not lose efficiency as the muzzle orifice is brought closer to the reflector; the design of the reflector clears directly to the vent. While this may be advantageous compared to some other silencers that clear loads radially and further aft of the blast baffle, it also creates a critical scenario in the silencer that decreases the amount of time available for FRP quench. For such a short silencer that is already subject to time-critical performance traits, this is an important factor. This is postulated to be one of the primary drivers of the FRP signature characterized above. With its fast initial momentum accumulation, FRP may present as almost 90% more severe than subsequent shots, to bystanders on average, on this weapon system.
PEW Science Research Note 3: Along with the aforementioned behaviors, the Monarch Recce exhibits gross suppression performance traits often characteristic of larger silencers. This is the second shortest silencer evaluated on the 10.3-in MK18 weapon system publicly, to date, the shortest being the KAC QDC/MCQ-PRT (6.156). The next longest silencer evaluated on the MK18 is the Otter Creek Labs Polonium-K (6.95), which is 5.3 inches long with its tested direct-thread mount. The Monarch Recce meets or exceeds the Polonium K in gross muzzle signature suppression performance and surpasses it in operator protection, due to both the advanced design and lower back pressure of the Recce. In addition to these gross performance differences, the Recce is also significantly more consistent in its signature propagation than is the Polonium-K. The reader is encouraged to reference Figure 2a in the respective reports, highlighting blast load impulse accumulation trends from shot to shot. Some other comparisons are below:
The next longest silencer evaluated on the MK18 is the short configuration of the PWS BDE 556 (6.123), at a 5.4-in tested length. The Recce outperforms the short BDE 556 significantly in consistency and flow rate.
The HUXWRX FLOW 556k (6.83) is 5.6 inches long, as tested. The Recce does not achieve the same level of operator risk reduction, but presents a superior pressure field, overall.
The Energetic Armament ARX (6.82) is 5.8 inches long, as tested on the MK18. The Monarch Recce provides performance that is significantly higher.
It is not until the tested length is increased to 6.1 inches that a silencer significantly outperforms the Recce; such a silencer is the CAT WB (6.129).
Interestingly, the Monarch Recce provides extremely competitive signature suppression performance and back pressure reduction on the MK18 to that of the Otter Creek Labs Infinity with vented 5.56 end cap (6.179). The Infinity has a tested length of 6.8 inches.
Other comparisons are available by filtering and sorting the table in the Rankings Section. Note that Members may use the Visualization Tool scatter plot to filter by length and weight.
PEW Science Research Note 4: It is extremely important for the reader to understand the Suppression Ratings are computed with free field test data, and are therefore universal when translating the weapon and operator to different environments without reflections. However, when the environment becomes complex with many reflecting surfaces, performance translation of different systems is not yet possible; sound field shapes and particle velocities result in varied blast wave time-of-arrivals, as well as changes of blast load angles of incidence; these variations change amplitude and phase waveform components. As a result of these inevitable environmental complexities, user impressions will vary, as both the shooter and bystander. Nonetheless, hazard reduction efficacy in the free field, as characterized by the Suppression Rating, holds. The Suppression Rating comparisons are the current state-of-the-art, and the most “apples to apples” sound suppression performance comparisons that currently exist. Further research is ongoing.
PEW Science Research Note 5: As in all semiautomatic AR15 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 87 ms in Figure 1a) the mechanical noise of the bolt closing is observed. The pressure signature of Shot 6 does not display this event due to the bolt remaining open after the sixth and final round is fired from the magazine.
PEW Science Research Note 6: The closing time of the AR-15 bolt is directly related to the flow restriction of a silencer for a given weapon system. PEW Science has determined bolt closing time variation from the unsuppressed state to be a reliable indicator of silencer back pressure, with strong correlation with the PEW Science Back Pressure Metric, Omega and the alpha parameter. However, PEW Science has also determined that the indicator is unreliable upon upper receiver fouling. Sound signatures are not influenced by this fouling, as these kinematics occur in late time, after gas venting to atmosphere. Momentum transfer, weapon condition (upper receiver fouling), and other factors, can significantly influence bolt closing time. PEW Science urges the reader to exercise extreme caution if using the published bolt closing time to make determinations regarding silencer flow restriction (back pressure) or weapon system kinematics. This type of calculation may provide erroneous results, as the weapon condition at the time of each test is not published data. The time-scale duration showing bolt closing time is only published by PEW Science such that the signature data pedigree may be verified.
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 automatic rifle firearm configuration.
As typically indicated, 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. Ammunition consistency can play a role in the determination of FRP, however, the close examination of measured pressure and impulse waveforms typically excludes ammunition from the possible factors influencing true FRP, due to the relative consistency of most high quality factory ammunition.
PEW Science Research Note 7: Note that the muzzle Suppression Rating of the FOR Systems Monarch Recce is 32.3 and the at-ear Suppression Rating is 24.9; different zones on the Suppression Rating Dose Chart. The lower back pressure of the Monarch Recce, along with its advanced muzzle suppression for its size, contributes to a less severe ejection port blast signature, which somewhat decreases shooter hazard on the standard MK18 weapon system. Weapon tuning will influence hazard reduction efficacy, and is outside the scope of this study.
The signatures measured at the shooter’s ear are presented and analyzed in the full Member Version of this report.
Gross performance comparisons with several other silencers on this weapon system are provided in the following section.
6.195.2 Suppression Rating Comparison (5.56x45mm from the MK18)
Figure 5 presents a comparison of the PEW Science Suppression Rating of the FOR Systems Monarch Recce with that of several other silencers on the MK18 weapon system. The standard PEW Science MK18 test host weapon system is described in Public Research Supplement 6.51.
Figure 5. Suppression Rating Comparisons of the FOR Systems Monarch Recce and other rifle silencers, Using PEW-SOFT 5.56x45mm Supersonic Test Data and PEW Science Analysis
Figure 5 presents an overall summary of the postulated hazards to the operator and bystanders when fielding a variety of different silencers on the standard MK18 weapon system. The FOR Systems Monarch Recce from this test program is shown in red. Hazards are expressed with the Suppression Rating; a holistic parameter that captures human inner ear damage risk potential from a measured impulsive complex blast overpressure signature during the entire time regime of weapon operation, including combustion, complete blowdown, and all mechanical operation, including the carrier group returning to battery, in the true free field. The parameter may be used with the dose chart at the beginning of this report. The PEW Science Suppression Rating is a damage risk criterion (DRC), a lower Suppression Rating indicates a higher personnel hazard in the free field - it is not a subjective quantity; it is an objective quantification of hearing damage risk potential. Due to its true free field test data origin and complete waveform analytical calculation basis, it is the only known universal suppressed weapon system signature comparison metric available. Analytically computed metrics are color-coded in the Rankings Table and keyed to the dose chart for user interpretation.
The following gross conclusions can be made from the metrics presented in Figure 5, above:
The FOR Systems Monarch Recce produces free field bystander hazard reduction on par with that of the following silencers, on the MK18:
The free field operator (shooter) hazard reduction of the FOR Systems Monarch Recce with the standard untuned MK18 weapon system is somewhat higher than it is with several other designs due to its higher flow rate (lower back pressure) and efficient muzzle suppression for its size. The MK18 operator protection with the Monarch Recce is on par with that of the:
The Monarch Recce exceeds the operator Suppression Rating performance of the Otter Creek Labs Polonium-30 (6.143), Infinity 7.62 with 5.56 solid end cap, and Engaged Industries Operator 5.56 (6.192).
As stated in Research Note 3, the FOR Systems Monarch Recce exhibits gross suppression performance traits often characteristic of larger silencers. This is the second shortest silencer evaluated on the 10.3-in MK18 weapon system publicly, to date, the shortest being the KAC QDC/MCQ-PRT (6.156). The next longest silencer evaluated on the MK18 is the Otter Creek Labs Polonium-K, which is 5.3 inches long with its tested direct-thread mount. Further comparisons are provided in that previous Research Note. The reader is encouraged to examine those comparisons, along with the Rankings Section for the full context of compact silencer performance in the current market.
Hybrid designs continue to demonstrate significant performance with supersonic ammunition suppression, and silencers like the Monarch Recce show that performance can be achieved in relatively compact design envelopes. The performance of the FOR Systems Monarch Recce is not significantly lower than that of a Surefire SOCOM556-RC2 (6.52) on this weapon system. And, the Recce provides superior operator protection in the free field. As the Recce silencer is over an inch shorter than the 556-RC2, this is a significant performance factor.
As detailed in this report, signature at the operator’s head is a function of both muzzle and ejection port signatures from the AR-15 weapon system. Specific weapon system parameters will dictate hazard reduction efficacy.
Small arm weapon system suppression performance is a spectrum. The PEW Science Suppression Rating and the Silencer Sound Standard help quantify this spectrum for end users and industry, objectively.
6.195.3 Review Summary: FOR Systems Monarch Recce on the MK18 5.56x45mm AR15 with 10.3-in Barrel
When paired with the 10.3-in barrel MK18 and fired with Federal XM193, the FOR Systems Monarch Recce with the Zilch HUB coupler and R2S flash hider mount achieved a composite Suppression Rating™ of 33.3 in PEW Science testing.
As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.
PEW Science Laboratory Staff Opinion:
The FOR Systems Monarch Recce is a compact high performance 5.56mm rifle silencer that is available in both 3D printed Inconel and titanium alloys. With extremely competitive gross signature suppression for its size, and a higher flow rate than typical for the type of performance it offers, the Monarch Recce represents a significant advancement in compact centerfire rifle suppression for the 10.3-in MK18 short barrel rifle. The silencer is HUB mount capable; the tested configuration is 5.13 inches long.
Like the previously evaluated FOR Systems Monarch 762, the Monarch Recce is a 3D printed Inconel silencer classified as a hybrid design, incorporating both high flow rate features and conventional geometries to control distal blast propagation while reducing adverse influence on weapon function. The Monarch Recce utilizes conventional baffle geometry with a multi-rimmed first reflector (blast baffle) and complete circumferential annular vent passages occupied by spiraled ribbing that terminates in distal vents around the outer circumference of the end plate. This method of annular utilization is becoming increasingly common in modern hybrid designs. In this silencer, the annular paths are less intricate, though still efficiently utilized; downstream geometry is modified as it is a lower pressure stage.
The FOR Systems Monarch Recce exhibits gross suppression performance traits often characteristic of larger silencers. This is the second shortest silencer evaluated on the 10.3-in MK18 weapon system publicly, to date, the shortest being the KAC QDC/MCQ-PRT. The next longest silencer evaluated on the MK18 is the Otter Creek Labs Polonium-K, which is 5.3 inches long with its tested direct-thread mount. Further comparisons are provided in the report body. The reader is encouraged to examine those comparisons, along with the Rankings Section for the full context of compact silencer performance in the current market.
The Monarch Recce does have noticeable FRP on this weapon system; that performance trait is a consequence of the tradeoffs that occur in this particular design to gain elevated flow rate. Nonetheless, when ejection port blast is the primary hazard (on untuned AR-15 systems), the operator may notice the FRP but not be subjected to undue hazard increase in the free field.
The Recce silencer may be used with a variety of mounts. It is postulated that proximity to the blast baffle is less important for this silencer, with regard to performance, than is mount vent structure. The user is encouraged to contact the manufacturer for questions regarding the influence of mount type to performance of this silencer.
PEW Science has not evaluated the durability of the Monarch Recce. However, as the silencer is available in both Inconel and titanium models, the user should remain cognizant of the inherent limitations of certain materials when adapted to their personal firing schedules. FOR Systems indicates that users should allow for a cool down period of 5 mins every 270 rounds of fully automatic fire through the Inconel model of the silencer. The user should contact FOR Systems to ensure compatibility for their use case.
In this review, the FOR Systems Monarch Recce performance metrics depend upon suppressing a supersonic centerfire rifle cartridge on a short barrel gas-operated rifle, which is an incredibly difficult task. PEW Science encourages the reader to remain vigilant with regard to all supersonic centerfire rifle suppression claims. The gas volume and combustion products created by the firing of the supersonic 5.56x45mm cartridge are significant; the measured pressure and impulse magnitudes, and their durations, illustrate this fact. Silencer performance on automatic (reciprocating) rifles depends on many factors. Weapon configuration may significantly influence total suppressed small arm system performance.
The hearing damage potential of supersonic centerfire rifle 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.
