SSS.6.199 - Wolfpack Armory Disruptor 556 and the M4A1 Mid-Gas 5.56x45mm 14.5-in Barrel Automatic AR15 Rifle (Free Version)
/Wolfpack Armory Disruptor 556 on the M4A1 Mid-Gas 5.56x45mm AR15 with 14.5-in Barrel
The Disruptor 556 is designed and manufactured by Wolfpack Armory. It is a 223 caliber centerfire rifle silencer, intended to suppress the 5.56x45mm cartridge with semiautomatic or fully automatic fire on barrel lengths greater than or equal to 10.5 inches. The Disruptor 556 has a 1.62-inch diameter and is 5.625 inches long with no mount. The silencer may be attached to a variety of weapon systems depending on the user’s choice of mount; the included Low Profile Plan B-compatible mount adapter and 1/2-28tpi Night Howler flash hider increase the system length to 5.94 inches. Other mounting options are possible due to the rear of the silencer body being HUB compatible (1.375-24 tpi threading). The fully-welded silencer body is constructed from 17-4 heat treated stainless steel, as is the removable end cap. The silencer weighs 9.8 ounces and the included mount system weighs 4 ounces, for a total system weight of 13.8 ounces, as tested. The Disruptor 556 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-Wolfpack-090-001-24. Therefore, data pertaining to the Disruptor 556 in this Sound Signature Review is published with the express written permission of JW Manufacturing LLC.
The testing and analysis presented in this Sound Signature Review are of the Disruptor 556 on the M4A1 Mid-Gas Automatic AR-15 rifle, chambered in 5.56x45mm NATO with a 14.5-inch barrel. Federal XM193 55gr ammunition was used in the tests. The standard PEW Science M4A1 test host weapon system is described in Public Research Supplement 6.127.
Section 6.199.1 contains Disruptor 556 test results and analysis.
Section 6.199.2 contains overall gross Suppression Rating comparisons of the Disruptor 556 with other rifle silencers on the current market on the M4A1 Mid-Gas Rifle, including various configurations of the Otter Creek Labs Infinity, Dillon DRC556, CAT TSWIF, Sylvan Arms SA223TIS, BOE Mod 1, Echo Zulu Defense X1R556-Ti, PTR VENT Spiritus 556i, HUXWRX FLOW 556 Ti, Surefire SOCOM556-MINI2, KAC QDC/CRS-PRT, KAC QDC/MCQ-PRT, CAT/WB/A1, and Surefire SOCOM556-RC2.
Section 6.199.3 contains an article summary and PEW Science laboratory staff opinions.
Summary: When paired with the 14.5-in barrel M4A1 and fired with Federal XM193, the Wolfpack Armory Disruptor 556 achieved a composite Suppression Rating™ of 27.6 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.
6.199.1 Wolfpack Armory Disruptor 556 Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Wolfpack Armory Disruptor 556 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. Wolfpack Armory Disruptor 556 Sound Metric Summary
6.199.1.1 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 Wolfpack Armory Disruptor 556 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 Shot 2 and Shot 3.
Fig 1a. Wolfpack Armory Disruptor 556 5.56x45mm NATO M4A1 Automatic Rifle Muzzle Sound Pressure Signature
Fig 1b. Wolfpack Armory Disruptor 556 5.56x45mm NATO M4A1 Automatic Rifle Sound Pressure Signature
Figure 2a. Wolfpack Armory Disruptor 556 5.56x45mm NATO M4A1 Automatic Rifle Muzzle Sound Impulse Signature
Figure 2b. Wolfpack Armory Disruptor 556 5.56x45mm NATO M4A1 Automatic Rifle Muzzle Sound Impulse Signature
The Wolfpack Armory Disruptor 556 is a conventional tubeless rifle silencer. The truncated, dished cone baffle walls form the outer diameter of the primary tube and are fully welded. The system has 6 baffles that are, for all intents and purposes, identical. There is no ancillary porting in the baffle stack or from the first expansion (blast) chamber other that the primary bore orifice. The bore orifice aperture is tighter than some other silencers that may accept 6 mm projectiles. The Disruptor 556 is a dedicated 5.56 mm unit.
The aforementioned characteristics of the silencer result in several observed performance attributes displayed in the above measured test data:
Blowdown is relatively long duration, and bolt carrier group return time is somewhat faster than typical (Fig. 1a).
Initial precursor and coupled jetting events are consistent and cleanly separated from primary blast, with significant first-round-pop divergence early in time, culminating with major jetting in both pressure space (Fig. 1b) and impulse space (Fig. 2a).
Post-FRP consistency is relatively stable with significant positive phase duration plateau (Fig. 2).
PEW Science Research Note 1: The dynamics observed in (1), the coupled jetting separation in (2), and the significant positive phase duration in (3), all support the conclusion that the Wolfpack Armory Disruptor 556 is a relatively high back pressure silencer. Furthermore, it is important to note than in addition to its high back pressure, there exists a likely pressure stagnation internally that drops its signature suppression efficiency. The lack of baffle porting is one of the primary drivers of this behavior, coupled with the dedicated 5.56 mm cartridge bore aperture. Further evidence of high back pressure is presented in Section 6.199.1.2 of the full Member Version of this report. FRP is relatively severe.
PEW Science Research Note 2: The previously discussed design attributes result in the performance of the Disruptor 556, in pure muzzle (bystander) suppression to be comparable to that of a Surefire SOCOM556-MINI2 (6.144) on this weapon system. The SOCOM556-MINI2 is 5 inches long in total and the Wolfpack Armory Disruptor 556 is approximately an inch longer, as tested. This comparable performance, and disparity in performance efficiency for length, is the result of the Total Signature Reduction Technology in the 556-MINI2 being more advanced. The Surefire technology allows stagnation relief to increase high pressure suppression efficiency in a considerably smaller design envelope. Unlike the 556-MINI2, the Disruptor 556 is not a hybrid design. Another 5-inch long hybrid, the CAT TSWIF (6.193) blast-diverter silencer, performs comparably to the Disruptor 556 at the muzzle, on this host weapon. Hybrid designs, both old and new, continue to show greater performance efficacy for a given size envelope, when compared to legacy conventional baffle designs in this combustion regime.
Note that conventional designs can achieve higher performance, but their lengths typically must increase. One example of a higher performing conventionally designed silencer on this weapon system is the 7-inch long Sylvan Arms SA223TIS (6.187). That silencer approaches the performance of a WARCOMP-equipped Surefire SOCOM556-RC2 (6.128) on this system.
Also note that the recently evaluated Dillon DRC556 (6.194) is only 5.75-inches long, as tested. The DRC556 design utilizes Purposely Induced Porosity (PIP) technology both internally and at venting locations. This is another example of high performance from a hybrid design.
PEW Science Research Note 3: As in all semiautomatic AR-15 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 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 4: 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 5: Note that the muzzle Suppression Rating of the Disruptor 556 is 27.1 and the at-ear Suppression Rating is 15.6; the same zone on the Suppression Rating Dose Chart. In the tested configuration, both the muzzle blast suppression inefficiencies and the back pressure of the Wolfpack Armory Disruptor 556 contribute to significantly elevated operator hazard from the standard M4A1 weapon system.
The signatures measured and analyzed at the shooter’s ear are presented in the full Member Version of this report.
Gross hazards and behaviors with the M4A1 weapon system are compared in the following section.
6.199.2 Suppression Rating Comparison (5.56x45mm from the M4A1)
Figure 5 presents a comparison of the PEW Science Suppression Ratings of the Wolfpack Armory Disruptor 556 with that of other rifle silencers on the M4A1 weapon system. The standard PEW Science M4A1 test host weapon system is described in Public Research Supplement 6.127. As PEW Science research with the M4A1 system continues, the dataset will be further populated.
Figure 5. Suppression Rating Comparisons of the Wolfpack Armory Disruptor 556 and the Dillon DRC556, CAT TSWIF, Sylvan Arms SA223TIS, BOE Mod 1, Echo Zulu Defense X1R556-Ti, PTR VENT Spiritus 556i, HUXWRX FLOW 556 Ti, KAC QDC/CRS-PRT, KAC QDC/MCQ-PRT, Surefire SOCOM556-MIN2, CAT WB, and SOCOM556-RC2 with different mounts, 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 Wolfpack Armory Disruptor 556 on the M4A1 weapon system with the included flash hider mount. Data is also presented for the fielding case of the Otter Creek Labs Infinity (6.196), Dillon DRC556 (6.194), CAT TSWIF (6.193), Sylvan Arms SA223TIS (6.187), BOE Mod 1 (6.183), Echo Zulu Defense X1R556-Ti (6.181), PTR VENT Spiritus 556i (6.176), HUXWRX FLOW 556 Ti (6.168), Surefire SOCOM556-RC2 (6.128), SOCOM556-MINI2 (6.144), and KAC QDC PRT units (6.156) on different muzzle devices, along with fielding of the CAT WB (6.130). Hazards are expressed with the Suppression Rating; a holistic parameter that captures human inner ear damage risk potential from a measured impulsive complex 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.
The following gross conclusions can be made from the above:
The Wolfpack Armory Disruptor 556 achieves hazard reduction to bystanders directly adjacent to the weapon system, in the free field, on the standard untuned M4A1RIII weapon system that is comparable to the Surefire SOCOM556-MINI2 and the CAT TSWIF, which are both an inch shorter than the Disruptor. Its gross free field suppression performance does eclipse that of the KAC 556 QDC/MCQ on this weapon system, though the MCQ is much shorter. The performance gap between the Disruptor 556 and the highest performing silencers, like the PTR VENT Spiritus, is extreme on this weapon system.
As a result of significant back pressure when compared to the other silencers, the free field operator (shooter) hazard reduction with the Disruptor 556 on the standard untuned M4A1RIII weapon system is significantly less robust. Another conventional non-hybrid design, the Sylvan Arms SA223TIS, also suffers from this phenomenon. In the free field, operator protection from the Disruptor 556 will be similar to that of a WARCOMP-equipped Surefire SOCOM556-MINI2 on this weapon system. That level of free field operator protection is also similar to that of a MAMS-equipped KAC QDC/MCQ-PRT on this weapon system.
In this combustion regime on the standard untuned 14.5-in mid-length gas M4A1RIII AR-15, there are silencers in the research pedigree that far exceed both the absolute muzzle suppression performance and operator protection of the Wolfpack Armory Disruptor 556, in the free field. This is largely a function of their technologies, and not their size.
It is important to note that the M4A1RIII is also a somewhat “over-gassed” rifle. Significant hazard reduction efficacy is extremely difficult to achieve without weapon modification. Furthermore, as discussed with in-depth analysis in previous Member Research Supplement 6.169 on the MK18, specific signature attributes and environmental factors can and will influence user perception and experience. Tuning of the M4 system for ejection port blast reduction may result in higher levels of overall operator hazard reduction performance with several silencers. FRP, however, will still influence operator hazard differentials during the first shot. That performance detriment can not be “tuned out” of the system without the use of some type of ablative medium.
Increased gross flow rate (lower back pressure) does pay dividends in ejection port blast hazard reduction to the 14.5-in barrel M4A1 midlength gas weapon operator, but without weapon modification, shooter’s ear protection levels may plateau. This has now been demonstrated several times with high performance silencers. Management of internal blast load impulse accumulation and flow rate in multiple time regimes is paramount for holistically balanced suppression performance on such weapon systems.
PEW Science Research Note 9: Unlike the case with hybrid silencers, technologies like that implemented in the Disruptor 556 scale relatively well with increased barrel length. Therefore, the performance differentials exhibited between the standard 10.3-in MK18 and 14.5-in M4A1RIII test host weapon systems are somewhat straightforward to predict. Although PEW Science urges extreme caution when attempting to extrapolate performance of a silencer between weapon systems, users should note that decreasing barrel length with this silencer will reduce pure muzzle suppression performance in this combustion regime. In general, caution is advised regarding applying these conclusions to the other systems without instrumented test data and engineering analysis, because performance differentials may be counterintuitive due to the complexities of some systems’ response to varying blast load input pressure(s) and duration(s).
As detailed in this report, the Suppression Rating at the shooter’s ear may be significantly influenced by the ejection port signature from an AR-15; all other things equal. For details on performance increases that are possible when “tuning” an AR-15 weapon system for a silencer, please see Review 6.111. It is important to note that not all silencers will possess a significant increase in shooter’s ear Suppression Rating from weapon tuning. 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 modification 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.
6.199.3 Review Summary: Wolfpack Armory Disruptor 556 on the M4A1 Mid-Gas 5.56x45mm AR15 with 14.5-in Barrel
When paired with the 14.5-in barrel M4A1 and fired with Federal XM193, the Wolfpack Armory Disruptor 556 achieved a composite Suppression Rating™ of 27.6 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 Wolfpack Armory Disruptor 556 is a full size and somewhat lightweight dedicated 5.56mm rifle silencer with HUB-mountable adaptability. With higher backpressure than many designs, weapon system tuning is highly recommended for the best user experience with this conventional baffle system. The silencer is fully welded, tubeless heat treated stainless steel, and is expected to be durable enough for most reasonable firing schedules. The end cap of the Disruptor 556 is removable for both repair and replacement.
The Wolfpack Armory Disruptor 556 is a conventional tubeless rifle silencer. The truncated, dished cone baffle walls form the outer diameter of the primary tube and are fully welded. The system has 6 baffles that are, for all intents and purposes, identical. There is no ancillary porting in the baffle stack or from the first expansion (blast) chamber other that the primary bore orifice. The bore orifice aperture is tighter than some other silencers that may accept 6 mm projectiles. The Disruptor 556 is a dedicated 5.56 mm unit.
The Disruptor 556 achieves hazard reduction to bystanders directly adjacent to the weapon system, in the free field, on the standard untuned M4A1RIII weapon system that is comparable to the Surefire SOCOM556-MINI2 and the CAT TSWIF, which are both an inch shorter than the Disruptor. Its gross free field suppression performance does eclipse that of the KAC 556 QDC/MCQ on this weapon system, though the MCQ is much shorter. The performance gap between the Disruptor 556 and the highest performing silencers, like the PTR VENT Spiritus, is extreme on this weapon system.
As a result of significant back pressure when compared to the other silencers, the free field operator (shooter) hazard reduction with the Disruptor 556 on the standard untuned M4A1RIII weapon system is significantly less robust. Another conventional non-hybrid design, the Sylvan Arms SA223TIS, also suffers from this phenomenon. In the free field, operator protection from the Disruptor 556 will be similar to that of a WARCOMP-equipped Surefire SOCOM556-MINI2 on this weapon system. That level of free field operator protection is also similar to that of a MAMS-equipped KAC QDC/MCQ-PRT on this weapon system.
Tuning of the AR-15 weapon system, with a heavier buffer, smaller gas port size, or both, is highly recommended when fielding the Disruptor 556, for the best user experience.
It is likely that the durability of the Disruptor 556 is adequate for most users on 5.56 NATO weapons. The silencer is HUB mount capable, and includes a “Q Plan-B”-compatible mount and flash hider. The user may adapt the silencer to a variety of mounting systems of their preference.
In this review, the Wolfpack Armory Disruptor 556 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.
