SSS.6.225 - Dead Air Lazarus 6 and the MK18 5.56x45mm Short Barrel Automatic AR15 Rifle (Free Version)
/Dead Air Lazarus 6 on the MK18 5.56x45mm AR15 with 10.3-in Barrel
The Lazarus 6 is designed by Dead Air Silencers. It is a .243 caliber centerfire rifle silencer, optimized to suppress the 6mm ARC and 5.56x45mm NATO cartridges. It has a 1.63-in diameter and is 5.2 inches long with no mount, 6.125 inches long with its Xeno flash hider installed and 5.4 inches long with a direct-thread mount installed, as tested. The rear of the silencer is threaded 1.375-24tpi to accommodate “HUB” compatible mounting systems. The silencer core and primary body assembly is 3D-printed Haynes 282 (nickel-chromium-cobalt alloy), whereas the other components are heat-treated stainless steel. The core of the silencer weighs 14.2 ounces. In the Xeno mount configuration, the silencer system weighs 19.3 ounces, total. In the direct-thread mount configuration, the silencer system weighs 15.1 ounces, total, as tested. The Lazarus 6 can be obtained from Silencer Shop.
Silencer Hazard Map:
The predicted personnel hazards generated by the tested weapon system in this report, in the free field, are shown in the adjacent Silencer Hazard Map. Click or tap the Map to enlarge. Please reference Silencer Hazard Map Brief 8.1.22 for further details. The PEW-SOFT HD Blast Hazard Prediction Tool and Hazard Mapper is presented in Report 8.1.1.
Dead Air Lazarus 6 xeno 10.3-in MK18 AR-15 Free Field Hazard Map Produced by PEW-SOFT HD Blast Hazard Prediction Tool using PEW Science Test Data
The testing and analysis presented in this Sound Signature Review contains two test evaluations of the Dead Air Lazarus 6 mounted with both a Xeno 3-Prong flash hider and direct-thread mount 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 tests. The standard PEW Science MK18 test host weapon system is described in Public Research Supplement 6.51.
Report Table of Contents:
Section 6.225.1 contains a Dead Air Lazarus 6 performance summary comparison with other silencers that are less than or equal to 6.125 inches long, inclusive of mount, on a suppressed 5.56 AR-15 SBR
Section 6.225.2 contains Dead Air Lazarus 6 test results and analysis mounted with the Xeno 3-Prong Flash Hider
Section 6.225.3 contains Dead Air Lazarus 6 test results and analysis mounted with a direct-thread mount (Members Only)
Section 6.225.4 contains overall Suppression Rating comparisons of the Dead Air Lazarus 6 with other silencers on the current market with additional commentary.
Section 6.225.5 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 Dead Air Lazarus 6 with the Xeno 3-Prong flash hider mount achieved a composite Suppression Rating™ of 30.8 in PEW Science testing.
When paired with the 10.3-in barrel MK18 and fired with Federal XM193, the Dead Air Lazarus 6 with a direct-thread mount achieved a composite Suppression Rating of 29.4 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.
6.225.1 Dead Air Lazarus 6 Performance Summary and Comparison to Comparable Length and Shorter Silencers on a Suppressed 5.56 AR-15 SBR
This report presents a third-party laboratory performance evaluation of the Dead Air Lazarus 6 silencer in two mounting configurations on the standard untuned 10.3-in MK18. When changing the mounting system of the Lazarus 6, the length and performance of the silencer changes. The silencer’s overall length may be up to 0.75-in shorter with a direct-thread mount than with the included Dead Air Xeno mounting system. The performance differential is not extreme. This conclusion may be significant to some users, as their individual mounting preferences may dictate the use of mounts shorter than the standard Xeno system.
For contextual performance comparison with other silencers on the same weapon system, suppression performance comparisons with silencers possessing a total system length of 6.125 inches or less, including mount, are presented below. The reader may sort and filter all public Rankings here to view the performance of more silencers.
Objectively, the top five performers are the safest for personnel in this length class and are likely to mask operator position from adversaries to the greatest degree. Also objectively, the bottom five performers produce the most dangerous environment in this length class for personnel and are likely to provide the least concealment of audible signature.
The top five performing systems that are less than 6.125 inches long on the MK18 showcased in public evaluations are:
The bottom five performing systems that are less than 6.125 inches long on the MK18 showcased in public evaluations are:
Dead Air Lazarus 6 (Direct-Thread) (6.225, this report)
All of the above silencers are relatively compact by current industry standards. Some of them are extremely compact (less than 5 inches long), including the KAC QDC/MCQ-PRT, CAT KK, and Stealth Additive Works Tisha. The performance disparity between the top 5 silencers and bottom five silencers is the result of technological advancement. All 5 top performers are hybrid designs. Only two of the bottom 5 performers are hybrid designs (Lazarus 6 and QDC/MCQ-PRT) and one is a Flow Through silencer (HX-QD 556K).
The modern hybrid designs provide the greatest performance potentials while balancing operator and bystander protection and weapon system reliability and longevity. Specifically, these types of silencers use early venting and different pressure stages to relieve stagnation and increase suppression efficiency in a given design envelope, while also significantly reducing back pressure. Hybrid designs are not Flow Through silencers, and misclassification is commonplace in the silencer industry; no Flow Through silencers exist other than those manufactured by HUXWRX (formerly OSS). For more details, performance evaluations, and in-depth signature comparisons of hybrid and conventional designs, the reader may examine analysis that is previously published in:
Member Research Supplement 6.103 (supersonic 5.56 NATO)
Member Research Supplement 6.115 (supersonic 7.62 NATO)
Member Research Supplement 6.124 (subsonic 300 BLK)
Member Research Supplement 6.169 (supersonic 5.56 NATO), and recently
Member Research Supplement 6.184 (subsonic 9mm).
To be clear, it is not the addition of a single design element that produces high performance from a small arm weapon system silencer. It is the combination and purposefully engineered integration of multiple design elements that give way to high holistic system performance.
The raw performance of the Dead Air Lazarus 6 in two mounting configurations is illustrated in Figure 1, below, along with that of the aforementioned top 5 and bottom 5 performing silencers on the MK18 in this <6.125 inch length class. The 3D-printed internal structure of the Lazarus 6 (Triskelion, similar in concept to the Mojave (6.177) series) possesses expedient blast chamber venting, over-bore for the 5.56mm cartridge, a high degree of surface area, and some distal venting. Its flow rate is relatively high and its blast momentum propagation is very controlled (significantly controlled when compared to the silencers in the MK18 dataset at large). The Lazarus 6 produces an extremely balanced risk field around the weapon system (its muzzle and ear Suppression Ratings are close together, regardless of mounting system, on this standard untuned host AR-15).
The host weapon system in Figure 1 is kept constant, and metrics shown are in terms of PEW Science Suppression Rating, which is a human risk metric calculated from raw free field blast overpressure test data. The calculated risk metrics for the unsuppressed case are also presented.
Figure 1. Suppression Rating Comparisons of rifle silencers Less than or equal to 6.125 inches long Using PEW-SOFT 5.56x45mm Supersonic MK18 Test Data and PEW Science Analysis
From the above data, three primary conclusions are apparent:
Silencer over-bore, in general, may reduce suppression performance. The Dead Air Lazarus 6, though more advanced than previous generation Dead Air rifle silencers like the Sandman-S (6.92), is over-bored for the 5.56mm NATO cartridge. The Energetic Armament silencer was purposely over-bored in an effort to reduce baffle erosion under heavy firing schedules. The KAC silencer is not significantly over-bored, but is relatively primitive in its design and its technology is not appropriate to produce high performance in the given system length envelope. Note that there are exceptions to over-bore performance reductions. That discussion is outside the scope of this report. Note that although some listed models in Figure 1 are not advertised as being compatible with 6mm ammunition, the manufacturer has indicated that they are. This does not mean the bore apertures of all the listed silencers are equal in size. Furthermore, most advanced rifle silencers have progressive bore apertures that vary longitudinally. This adds another variable for performance and durability / longevity comparisons.
High flow rate technologies have advanced. The Flow Through technology in HUXWRX (OSS) rifle silencers advanced significantly between the introduction of the HX-QD 556K and FLOW 556K (6.83). The FLOW 556K is shorter and higher performance than the HX-QD 556K. Post-Flow Through hybrid designs have further advanced after the introduction of the FLOW 556K, combining high flow rates with superior distal momentum propagation control. Such examples include the FOR Systems Monarch Recce, CAT KK, and others.
Rifle silencer suppression technology, overall, continues to advance at a rapid pace. The Stealth Additive Works and CAT SURGE BYPASS technologies are extremely advanced. The Triskelion technology in the Dead Air Lazarus 6 is also advanced in that it provides extremely consistent and balanced high flow rate performance, for the size. Other technologies do provide more advanced signature suppression than the Triskelion implementation in the Lazarus 6, but over-bore may also be a factor. In general, the most advanced systems currently available are also optimized and produced with advanced manufacturing.
Additive manufacturing is required in order to implement the engineering solutions present in many of the most advanced silencers. However, it is not only purposeful design and advanced manufacturing that can contribute to high performance for the end user. Some designs perform better than others, even in the same size classes; there are clear behavioral differences that are showcased with real measured test data and engineering analysis. The performance differentials may be nontrivial, even between new technologies released today. The above metrics are calculated from test data generated on a standard untuned host; weapon system tuning may raise performance potentials, as has been demonstrated in previous public research.
Detailed Dead Air Lazarus 6 test data and analysis follows.
6.225.2 Dead Air Lazarus 6 Xeno Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Dead Air Lazarus 6 Xeno 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. Dead Air Lazarus 6 Xeno Sound Metric Summary
6.225.2.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 6-shot test acquired with PEW-SOFT™ are shown below. Six cartridges were loaded into the magazine, 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 Dead Air Lazarus 6 Xeno are shown in Figure 2a. The sound signatures of Shot 1 and Shot 2 are shown in Figure 12b, in early time. The real sound impulse (momentum transfer potential) histories from the same 6-shot test are shown in Figure 3a. In Figure 3b, a shorter timescale is shown comparing the impulse of Shot 1 to that of Shots 2 and 3.
Fig 2a. Dead Air Lazarus 6 Xeno 5.56x45mm NATO MK18 Automatic Rifle Muzzle Sound Pressure Signature
Fig 2b. Dead Air Lazarus 6 Xeno 5.56x45mm NATO MK18 Automatic Rifle Sound Pressure Signature
Figure 3a. Dead Air Lazarus 6 Xeno 5.56x45mm NATO MK18 Automatic Rifle Muzzle Sound Impulse Signature
Figure 3b. Dead Air Lazarus 6 Xeno 5.56x45mm NATO MK18 Automatic Rifle Muzzle Sound Impulse Signature
The Dead Air Lazarus 6 is a relatively advanced hybrid design. Gross features of note in the silencer include early blast chamber venting, spiral geometry features on each of its three baffles that vary, and a relatively high degree of surface area throughout with circumferential distal venting around the end cap. More specific design features include:
The geometry of the first reflector array (blast baffle) in the silencer has integrated angled splines that terminate on the reflecting surface. The early venting is accomplished between the splines into annular cavities around the baffle faces. The reflector (and each of the other baffle reflectors) has a large step, similar to legacy KAC crimped-cone baffle technology.
The two forward baffles are similar in overall reflecting geometry to the Triskelion technology used in the previously evaluated Mojave pistol silencer, though they are not identical.
Circumferential distal venting that terminates at the silencer end most likely bypasses the last expansion chamber.
The above design features enable the Lazarus 6 to exhibit a relatively high flow rate and the high degree of surface area and venting control result in very consistent blast momentum propagation; the signature from the silencer is very consistent, from shot to shot. Combined high flow rate and consistency, with an over-bored silencer for 5.56, is notable.
Similar to some other high flow rate silencers, the Lazarus 6 produces a risk field that is forward-biased, away from the operator. However, its flow rate is so high, and its downstream momentum control not as robust, so bystanders adjacent to the weapon system are at somewhat higher risk than from some other competing models (as discussed in the introductory section of this report). This behavior is illustrated in the Silencer Hazard Map at the beginning of this report and in Silencer Hazard Map Brief 8.1.22.
PEW Science Research Note 1: The following observations are made from the above test data:
Relatively high free field blast overpressure amplitude with expedient blowdown and relatively late time bolt carrier group (BCG) return to battery (Fig. 2a).
Significant precursor and coupled jet flows in early time followed closely by a significant primary jet event and high amplitude blowdown through the primary phase (Fig. 2b).
Minimal first-round-pop (FRP) divergence with a gradual decrease in momentum accumulation rate through the shot string (Fig. 3a and 3b).
Relatively consistent peak momentum accumulation (Fig. 3b).
Again, it is notable for a high flow rate silencer to exhibit the consistency observed in (4). The lack of FRP is also notable. While it is true the Lazarus 6 projects more severe hazard adjacent to and forward of the weapon system than some other competing designs, it is also relatively compact. These types of performance tradeoffs are commonplace. It is likely that overall suppression performance would be increased with a bore aperture change, though the degree to which the hazards would be reduced is unknown. Lengthening of the silencer nominally while introducing some internal complexity could potentially provide greater performance dividends with this technology.
PEW Science Research Note 2: It is important to note that the flow rate of the Lazarus 6 can be influenced by mounting system. PEW Science testing indicates that the use of a direct-thread mount with this silencer, instead of the included Xeno 3-Prong flash hider system, decreases the rate at which distal momentum propagates from the silencer, but increases its amplitude. This results in a net offset and the same muzzle Suppression Rating, but the flow rate reduction does impact operator hazard, somewhat dropping the shooter’s ear Suppression Rating. This is reflected in comparison charts and the Rankings. Section 6.225.3 of this report (Members Only) displays an example of the direct-thread test data and provides further technical discussion of the behavior.
PEW Science Research Note 3: The Triskelion technology previously evaluated in the modular Dead Air Mojave (6.177) pistol silencer appears to bring requisite efficiency to higher combustion pressure and volume regimes, in accordance with this Lazarus 6 test data and analysis. Like its pistol caliber implementation, again, reduction in the number of baffles causes steep performance drop-off. This is to be expected.
PEW Science Research Note 4: At the time of writing, the measured performance of the Dead Air Lazarus 6 places it close to the Top 30 in the overall MK18 PEW Science Rankings, slightly above the Q Southpaw (6.189). However, it should be noted that the Southpaw has significantly more back pressure than the Lazarus 6, despite the Southpaw being larger, and the Southpaw’s Suppression Rating at the shooter’s ear on the standard untuned MK18 is lower, as result. To put this in further context, the Lazarus 6 is in the Top 15 of the MK18 Rankings in shooter’s ear Suppression Rating, again, on an untuned host weapon. These performance distinctions are extremely important to understand, particularly considering total silencer system lengths (with mounts). For further context regarding both performance and size balance, the reader is encouraged to use the Suppression Rating Parametric Visualization Tool (Members Only) for independent study.
PEW Science Research Note 5: 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. The reader should note that shooting a Lazarus 6 indoors and a HUXWRX FLOW silencer indoors may result in different blast overpressure risk profiles.
PEW Science Research Note 6: 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 87 ms in Figure 2a) 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 7: 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 8: Note that the muzzle Suppression Rating of the Dead Air Lazarus 6 is 27.0 and the at-ear Suppression Rating is 27.6; the same zone on the Suppression Rating Dose Chart. The high flow rate (low back pressure) of the Lazarus 6, along with its consistent forward-biased muzzle signature, contributes to a less severe ejection port blast signature and muzzle blast hazard field around the operator, which further decreases shooter hazard on the standard MK18 weapon system. The reader is encouraged to examine the Silencer Hazard Map at the top of this report as detailed in Silencer Hazard Map Brief 8.1.22. Weapon tuning will influence hazard reduction efficacy, and is outside the scope of this study.
The signatures measured at the shooter’s ear with the same Xeno mounting system are presented and analyzed in the full Member Version of this report.
6.225.3 Dead Air Lazarus 6 Direct-Thread Sound Signature Test Results (Members Only)
A summary of the principal Silencer Sound Standard performance metrics of the Dead Air Lazarus 6 direct-thread mounted is shown in Table 2. The data acquired 1.0 m (39.4 in) left of the muzzle and 0.15 m (6 in) right of the shooter’s ear for this configuration of the Lazarus 6 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. Dead Air Lazarus 6 Direct-Thread Sound Metric Summary
6.225.3.1 SOUND SIGNATURES AT THE MUZZLE and Ear
The data acquired 1.0 m (39.4 in) left of the muzzle and 0.15 m (6 in) right of the shooter’s ear for this configuration of the Lazarus 6 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.
Note that PEW Science Members also have access to a very powerful comparison tool in the Rankings, which can filter for length and weight.
6.225.4 Suppression Rating Comparison (5.56x45mm from the MK18)
Figure 10 presents a comparison of the PEW Science Suppression Rating of the Dead Air Lazarus 6 Xeno and Direct-Thread silencer configurations with that of several other silencers of comparable length on the MK18 weapon system. The standard PEW Science MK18 test host weapon system is described in Public Research Supplement 6.51. Note that for more comparisons, including silencers of all lengths, the reader may view the comprehensive filterable and sortable table in the Rankings Section of the Standard.
Figure 10. Suppression Rating Comparisons of rifle silencers Less than or equal to 6.125 inches long Using PEW-SOFT 5.56x45mm Supersonic MK18 Test Data and PEW Science Analysis
Figure 6 presents an overall summary of the postulated hazards to the operator and bystanders when fielding a variety of different short silencers on the standard MK18 weapon system. The Dead Air Lazarus 6 configurations from this test program are 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 and Hazard Map 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, in all Silencer Hazard Maps, and keyed to the dose chart for user interpretation.
In addition to the gross conclusions that were presented in the first section of this report using the above presented comparison data in Figure 10, the following gross conclusions can be made from the metrics presented in the overall Rankings section
The Dead Air Lazarus 6 produces free field bystander hazard reduction on par with the following silencers on the MK18 weapon system:
The free field operator (shooter) hazard reduction of the Dead Air Lazarus 6 with the standard untuned MK18 weapon system is higher than it is with several other designs due to its higher flow rate (lower back pressure) and its relatively efficient muzzle suppression for its size. The MK18 operator protection with the Lazarus 6 Xeno mounted is on par with or exceeding that of the:
PEW Science Research Note 12: Without weapon system tuning, operator hazards from a suppressed MK18, in the free field, plateau at Suppression Ratings near 30. This is due to ejection port blast loads. However, this does not mean that silencers with similar shooter’s ear Suppression Ratings will sound the same to the shooter, in the free field. On the contrary, what an operator hears through the entire time regime of a gun shot event and subsequent environmental reflections, and which acute hazards manifest, may be different. The reader is strongly encouraged to review the published Silencer Hazard Map at the top of this report and in Silencer Hazard Map Brief 8.1.22. Furthermore, to illustrate two extremes, the difference in spatial hazards from a Flow Through silencer and a high back pressure silencer are directly compared in Silencer Hazard Map Brief 8.1.5 (HUXWRX FLOW 556k vs. SilencerCo Saker 556).
As stated in Research Note 4, at the time of writing, the measured performance of the Dead Air Lazarus 6 places it close to the Top 30 in the overall MK18 PEW Science Rankings, slightly above the Q Southpaw (6.189). However, it should be noted that the Southpaw has significantly more back pressure than the Lazarus 6, despite the Southpaw being larger, and the Southpaw’s Suppression Rating at the shooter’s ear on the standard untuned MK18 is lower, as result. To put this in further context, the Lazarus 6 is in the Top 15 of the MK18 Rankings in shooter’s ear Suppression Rating, again, on an untuned host weapon. These performance distinctions are extremely important to understand, particularly considering total silencer system lengths (with mounts). For further context regarding both performance and size balance, the reader is encouraged to use the Suppression Rating Parametric Visualization Tool (Members Only) for independent study.
Hybrid designs continue to demonstrate significant performance with supersonic ammunition suppression, and silencers like the Lazarus 6, and others, show that performance can be achieved in compact design envelopes. The overall balanced performance of these next generation systems are significantly elevated when compared to that of highly prolific previous generation hybrids such as the Surefire SOCOM556-RC2 (6.52) and other newly released military silencer hybrids such as the KAC PRT family (6.156) on this weapon system. Users now have additional high performance practical options to reduce weapon system length and maintain hazard reduction.
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.
6.225.5 Review Summary: Dead Air Lazarus 6 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 Dead Air Lazarus 6 with the Xeno 3-Prong flash hider mount achieved a composite Suppression Rating™ of 30.8 in PEW Science testing.
When paired with the 10.3-in barrel MK18 and fired with Federal XM193, the Dead Air Lazarus 6 with a direct-thread mount achieved a composite Suppression Rating of 29.4 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 Dead Air Lazarus 6 is a mid- to full-size hard-use 5.56 silencer with extremely balanced suppression performance and flow rate. The silencer is printed from Haynes 282 alloy and uses advanced hybrid geometry to achieve remarkably consistent blast propagation control for its high flow rate. Although its gross suppression performance is lower than some competing advanced models, its consistency and relatively low mount sensitivity may be attractive to many users. HUB compatible, the silencer exhibits a low degree of performance reduction when using a direct-thread mount instead of the included Xeno flash hider, for example. The durability, low back pressure, and overall consistent performance of the Lazarus 6 is objectively improved compared with previous generation Dead Air rifle silencer technology.
The Dead Air Lazarus 6 is a relatively advanced hybrid design. Gross features of note in the silencer include early blast chamber venting, spiral geometry features on each of its three baffles that vary, and a relatively high degree of surface area throughout with circumferential distal venting around the end cap. These design features enable the Lazarus 6 to exhibit a relatively high flow rate and the high degree of surface area and venting control result in very consistent blast momentum propagation; the signature from the silencer is very consistent, from shot to shot. Combined high flow rate and consistency, with an over-bored silencer for 5.56, is notable. Similar to some other high flow rate silencers, the Lazarus 6 produces a risk field that is forward-biased, away from the operator. However, its flow rate is so high, and its downstream momentum control not as robust, so bystanders adjacent to the weapon system are at somewhat higher risk than from some other competing models.
At the time of writing, the measured performance of the Dead Air Lazarus 6 places it close to the Top 30 in the overall MK18 PEW Science Rankings, slightly above the Q Southpaw. However, it should be noted that the Southpaw has significantly more back pressure than the Lazarus 6, despite the Southpaw being larger, and the Southpaw’s Suppression Rating at the shooter’s ear on the standard untuned MK18 is lower, as result. To put this in further context, the Lazarus 6 is in the Top 15 of the MK18 Rankings in shooter’s ear Suppression Rating, again, on an untuned host weapon. These performance distinctions are extremely important to understand, particularly considering total silencer system lengths (with mounts). For further context regarding both performance and size balance, the reader is encouraged to use the Suppression Rating Parametric Visualization Tool (Members Only) for independent study.
The Lazarus 6 is only 5.2 inches long without a mount. The tested included Xeno mount coupler and Xeno 3-Prong flash hider mount increase system length by almost an inch, whereas the tested direct-thread mount only nominally increases the system length. Although the direct-thread mount is shown in testing to somewhat increase back pressure, the increase is not extreme. Operator hazard on the standard untuned test host was only marginally increased, as reflected in the shooter’s ear Suppression Rating comparisons.
The primary section of the Lazarus is constructed from Haynes nickel-chromium-cobalt alloy and is therefore, like Inconel, expected to offer requisite durability and longevity for aggressive firing schedules. PEW Science has not evaluated the durability of this silencer. As always, the user should remain cognizant of their personal firing schedules. The user should contact Dead Air to ensure compatibility for their use case.
In this review, the Dead Air Lazarus 6 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.
