SSS.6.229 - Tuna Cans 5.56 XL and WRMFZY 5.56 and the M4A1 Mid-Gas 5.56x45mm 14.5-in Barrel Automatic AR15 Rifle (Free Version)

/

Tuna Cans 5.56 XL and WRMFZY 5.56 on the M4A1 Mid-Gas 5.56x45mm AR15 with 14.5-in Barrel

The 5.56 XL is designed and manufactured by Tuna Cans. It is a .223 caliber centerfire rifle silencer, intended to suppress the 5.56x45mm NATO cartridge on reciprocating weapons with barrel lengths of 10 inches and longer. It has a 1.5-inch diameter and the silencer core is modular; 12 baffles are included with the silencer and all, none, or an intermediate number of baffles can be used.  In its full 12-baffle configuration, without a mount, it is 9.25 inches long.  With the direct-thread mount included with the test specimen, the silencer is 9.81 inches long.  The silencer is HUB compatible, possessing 1.375-24 tpi rear mount threading.  The entirety of the silencer is heat-treated 17-4 stainless steel.  As tested, silencer weighs 29.5 ounces.

The WRMFZY 5.56 is also designed by Tuna Cans. Also a .223 caliber centerfire rifle silencer, it is intended to suppress the 5.56x45mm NATO cartridge on reciprocating weapons with barrel lengths of 10 inches and longer.  This silencer can also accommodate 6mm cartridges. It has a 1.85-inch diameter and the silencer core is monolithic; it is 3D-printed stainless steel.  The silencer is HUB compatible, possessing 1.375-24 tpi rear mount threading. As tested with a direct-thread mount, the silencer is 6.94 inches long and weighs 24.2 ounces.

Both the 5.56 XL and WRMFZY 5.56 silencers can be obtained from Tuna Cans.

System Suppression Ratings and Silencer Hazard Maps:

This report includes two (2) different tests of two (2) silencers.  Both the 5.56 XL and WRMFZY 5.56 are evaluated on the 14.5-in barrel M4 short barrel rifle. Composite and Detailed Suppression Ratings, along with the predicted personnel hazards generated by the tested weapon systems in this report in the free field, are shown in the below graphics and Silencer Hazard Maps. Click or tap the Maps to enlarge. Please reference Silencer Hazard Map Brief 8.1.26 for further details.  The PEW-SOFT HD Blast Hazard Prediction Tool and Hazard Mapper is presented in Report 8.1.1.

Tuna Cans 5.56 XL 14.5-in M4A1 AR-15 Free Field Hazard Map Produced by PEW-SOFT HD Blast Hazard Prediction Tool using PEW Science Test Data

Tuna WRMFZY 5.56 14.5-in M4A1 AR-15 Free Field Hazard Map Produced by PEW-SOFT HD Blast Hazard Prediction Tool using PEW Science Test Data

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-Tuna-152-001-26. Therefore, data pertaining to the 5.56 XL and WRMFZY 5.56 in this Sound Signature Review are published with the express written permission of Tuna Cans LLC.

The testing and analysis presented in this Sound Signature Review are of both the Tuna Cans 5.56 XL and WRMFZY 5.56 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 test. The standard PEW Science M4A1 test host weapon system is described in Public Research Supplement 6.127.

Report Table of Contents:

  • Section 6.229.1 contains an abbreviated overall summary of the Tuna Cans 5.56 XL (12-baffle) and WRMFZY 5.56 rifle silencer performance  on the 14.5-in M4, compared with the Top 5 silencers on this platform in the current Rankings.

  • Section 6.229.2 contains Tuna Cans 5.56 XL (12-baffle) test results and analysis.

  • Section 6.229.3 contains Tuna Cans WRMFZY 5.56 test results and analysis.

  • Section 6.229.4 contains overall Suppression Rating comparisons of the Tuna Cans silencers with other rifle silencers on the current market on the M4A1 Mid-Gas Rifle, including various configurations of the CAT ST, Otter Creek Labs OCM5 and OCM6, Whiskey Quebec 5.56 Purged and Non-Purged, Wolfpack Armory Disruptor 556, 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 6.229.5 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 direct-thread mounted, the Tuna Cans 5.56 XL in the 12-baffle configuration  achieved a Suppression Rating™ of 41.0 in PEW Science testing.  With the same weapon system, mounted the same way, the Tuna Cans WRMFZY 5.56 achieved a Suppression Rating of 41.3.

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.

6.229.1 Tuna Cans 5.56 Silencer Automatic Rifle Suppression Performance Summary

The PEW Science Silencer Sound Standard includes the 5.56x45mm NATO evaluation of many rifle silencers.  Comprehensive performance Rankings are tabulated in Section 7 of the Standard.  This report examines the performance of two Tuna Cans 5.56 silencers.  The scope of this report contains standard untuned 14.5-in M4A1 weapon system combustion suppression analysis of the Tunas Cans 5.56 XL and WRMFZY 5.56 silencers.

Figure 1 presents a gross performance comparison of the two Tuna Cans 5.56 silencers on the M4A1 with the unsuppressed case, along with the Top 5 performing silencers on this platform from the Rankings.  The silencers are presented in order of mounted length past the barrel shoulder, from shortest to longest.

Figure 1. Suppression Rating Comparisons of Tuna Cans 5.56 Rifle Silencers with the Top 5 5.56 Rifle Silencers Using PEW-SOFT 5.56x45mm Supersonic M4A1 Test Data and PEW Science Analysis

The Top 5 performing silencers on the 5.56 M4 from the current performance Rankings shown in the above table, in order of mounted length past the barrel shoulder from shortest to longest, are the:

  1. Dillon DRC556 (6.194)

  2. PTR VENT Spiritus 556i (6.176)

  3. Combat Application Technologies CAT/ST (6.217)

  4. Otter Creek Labs OCM 5 (6.213)

  5. BOE Suppression Mod 1 (6.183)

All of the above silencers (even arguably the Mod 1) are hybrid designs, in that they possess elements of both conventional and high flow rate silencers, coupled with other technology variations and staged elements to provide parametrically varied performance attributes.  However, both Tuna Cans silencers are not.  Both the 5.56 XL and WRMFZY 5.56 use conventional cone baffles with no venting, annular cavities, or flow directing features other than ridges on the baffle walls and in the case of the printed WRMFZY silencer, alternating the direction of each oblong bore orifice in each baffle.

Due to the type of technology used in the Tuna Cans 5.56 XL and WRMFZY 5.56, the above comparisons help to highlight several known phenomena and performance conclusions:

  1. Even conventional silencer technologies can provide competitive gross signature suppression performance if the design envelopes are large enough, in some combustion regimes. For example, at 9.8 inches long, the 12-baffle 5.56 XL silencer is able to cross the muzzle Suppression Rating threshold of 40 on this weapon system despite using only ridged cone baffles and a 1.5-in outer diameter. The number of baffles helps significantly. The back pressure of the silencer is high, but that is the consequence of this conventional design. The WRMFZY 5.56 silencer is also able to cross the 40 threshold, 1.0 m left of the end cap of the silencer. In this case, the silencer is shorter, but with a diameter increase to 1.85 inches, the additional volumetric expansion in the silencer enables the conventional technology to compete with high average suppression levels.  Note that volume, alone, is not the primary driver of signature suppression.  As noted, the pure muzzle suppression from the CAT ST eclipses that of the other silencers, and it has a 1.6-in diameter and 6.6-in mounted length.

  2. Operator protection on an untuned M4 almost always suffers without system tuning. The rifle is over-gassed, purposely by the manufacturer, for reliability purposes. This is the case with many stock AR-15 rifles. Even purposefully high flow rate silencers like the Spiritus 556i produce operator Suppression Rating metrics in the 20s on this standard host.

  3. Operator protection is not necessarily correlated with “gas to the face” on an AR-15 system. Back pressure in a silencer, which is a function of internal early- and late-time flow rates, influences the severity of both ejection port blast and late-time gaseous byproducts of combustion from the chamber and gas tube, escaping from the ejection port of the rifle.  Blowback can vary based on the rifle system, ammunition, firing schedule, and mounting system, even with the same silencer.  In the case of the silencers in the above chart, all possess varying flow rates, and some provide less “gas to the face” than others, despite the operator (shooter’s ear) Suppression Ratings being somewhat similar on this standardized host rifle. Again, as stated in (2), the rifle is over-gassed, which reduces the resolution of ejection port blast correlation with back pressure. Nonetheless, as detailed in the raw shooter’s ear waveforms measured with both Tuna Cans silencers in the tests and documented in this report, severe back pressure signs are visible.  These should be viewed as supplementary indicators in the analysis. Similar severe back pressure signs are present in the Otter Creek Labs OCM5 evaluation, for example.  The severe back pressure signs are not present in the raw blast test data of the BOE Mod 1, PTR VENT Spiritus, CAT ST, or Dillon DRC556.

The detailed 5.56x45mm NATO 14.5-in M4A1 evaluations of the Tuna Cans 5.56 XL 12-baffle and WRMFZY 5.56  rifle silencer follow.

6.229.2 Tuna Cans 5.56 XL 12-Baffle Sound Signature Test Results

A summary of the principal Silencer Sound Standard performance metrics of the Tuna Cans 5.56 XL with all of its 12 baffles installed 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. Tuna Cans 5.56 XL Sound Metric Summary

 

6.229.2.1 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 Tuna Cans 5.56 XL are shown in Figure 2a. 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 3a. In Figure 3b, a shorter timescale is shown comparing the impulse of Shot 1 to that of Shots 2 and 3.

Fig 2a. Tuna Cans 5.56 XL 5.56x45mm NATO M4A1 Automatic Rifle Muzzle Sound Pressure Signature

Fig 2b. Tuna Cans 5.56 XL 5.56x45mm NATO M4A1 Automatic Rifle Sound Pressure Signature

Figure 3a. Tuna Cans 5.56 XL 5.56x45mm NATO M4A1 Automatic Rifle Muzzle Sound Impulse Signature

Figure 3b. Tuna Cans 5.56 XL 5.56x45mm NATO M4A1 Automatic Rifle Muzzle Sound Impulse Signature

As described in the report introduction, Tuna Cans 5.56 XL uses conventional straight-cone baffles with ridges to increase surface area and turbulence which both influence heat transfer and signature suppression.  The notched cones, arranged in the full 12-baffle array in the tested specimen, produce significant flow restriction throughout the time regime of combustion blowdown and throttle gas momentum to atmosphere to a significant degree.  In this 9.8-in long configuration, the silencer achieves relatively high signature suppression performance, on average.

PEW Science Research Note 1: The above raw blast overpressure and impulse data measured during the test of the 5.56 XL offers windows into specific behaviors of the silencer:

  1. Blast load blowdown duration is relatively long with bolt carrier group (BCG) return to battery faster than with some other silencers (Fig. 2a).

  2. Initial precursor flow is significantly suppressed and initial coupled jetting is extremely consistent (Fig. 2b).

  3. First-round-pop (FRP) divergence happens early and aggressively (Fig. 2 and Fig. 3). FRP momentum ramp is severe in both accumulation rate and peak amplitude, in both pressure and impulse space.

  4. Post-FRP momentum throttle consists of two primary phases; immediate and secondary plateaus. Momentum is throttled for long duration (Fig. 3b).

The technology in the Tuna Cans 5.56 XL is well studied in the state of practice. With enough baffles (12), it produces significantly suppressed muzzle blast, with high back pressure, and severe FRP.

PEW Science Research Note 2:  Brute-force signature suppression methods are not without precedent in the state of practice. However, typically, these designs are used in subsonic ammunition combustion regimes to produce extremely low amplitude signatures.  One well-known example from the research is the Q Full Nelson (6.99).  The Full Nelson has copious straight-cone ported baffles in its design and does produce significantly high subsonic 300 BLK suppression performance.  Due to the conventional design, performance begins to suffer significantly with subsonic ammunition if the number of baffles are reduced, as shown in the severe FRP signatures produced by the Q Half Nelson (6.29). These silencers also have high back pressure. When used with higher pressure and volume combustion input, like .308 for example, the performance of that technology plateaus, as examined in the Q Thunder Chicken (6.20) research, for example.  The high pressure suppression performance can be improved as baffles are added, but pressure stagnation in the stack limits performance. It is not until ancillary flow paths are added with annular cavities locally or globally in the silencer that performance potentials begin to meaningfully and steadily increase, regardless of gross volume.  Similarly, the Tuna Cans baffle technology scales only so far. It is likely that if using half of the baffles, suppression would suffer but back pressure would not be reduced significantly, as the early time flow rate is fixed. That examination is outside the scope of this study.

PEW Science Research Note 3:  FRP with the 12-baffle configuration of the Tuna Cans 5.56 XL is relatively significant. Bystanders and the operator will be subject to less blast hazards after the first shot in a multi-shot string.

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 AR15 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 may be 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 entire signatures are used in analysis and Suppression Rating calculations.

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 Tuna Cans 5.56 XL is 40.9 and the at-ear Suppression Rating is 21.6; considerably different zones on the Suppression Rating Dose Chart. The higher back pressure of the 5.56 XL relative to other models and the “over gassed” nature of the rifle contributes to severe ejection port blast signature when compared to lower back pressure silencers on the standard untuned M4A1 weapon system. System tuning (adjustable gas block or heavier buffer mass) may be required to optimized the user’s particular weapon system.  Weapon tuning may influence hazard reduction efficacy, and is outside the scope of this study.

The signatures measured at the shooter’s ear with the Tuna Cans 5.56 XL are presented and analyzed in the full Member Version of this report.

This concludes the analysis of the Tuna Cans 12-baffle 5.56 XL silencer on the M4. Below, the analysis of the test data of the Tuna Cans WRMFZY 5.56 silencer is presented, on the same standard untuned M4 rifle.

6.229.3 Tuna Cans WRMFZY 5.56 Sound Signature Test Results

A summary of the principal Silencer Sound Standard performance metrics of the Tuna Cans WRMFZY 5.56 is shown in Table 2. 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 2. Tuna Cans WRMFZY 5.56 Sound Metric Summary

 

6.229.3.1 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 Tuna Cans WRMFZY 5.56 are shown in Figure 6a. The sound signatures of Shot 1 and Shot 2 are shown in Figure 6b, in early time. The real sound impulse (momentum transfer potential) histories from the same 6-shot test are shown in Figure 7a. In Figure 7b, a shorter timescale is shown comparing the impulse of Shot 1 to that of Shots 2 and 3.

Fig 6a. Tuna Cans WRMFZY 5.56x45mm NATO M4A1 Automatic Rifle Muzzle Sound Pressure Signature

Fig 6b. Tuna Cans WRMFZY 5.56x45mm NATO M4A1 Automatic Rifle Muzzle Sound Pressure Signature, short time window

Fig 7a. Tuna Cans WRMFZY 5.56x45mm NATO M4A1 Automatic Rifle Muzzle Sound Impulse Signature

Fig 7b. Tuna Cans WRMFZY 5.56x45mm NATO M4A1 Automatic Rifle Muzzle Sound Impulse Signature, short time window

The Tuna Cans WRMFZY 5.56 silencer uses the same baffle technology as present in the modular 5.56 XL silencer, in a non-modular 3D-printed configuration that is larger diameter but shorter. The baffle type is almost identical in that they are straight cones with ridged bodies; the baffle orifices, however, are alternating oblong shapes, instead of notched.

Because the baffle type in both silencers are so similar, and they are tested on the same weapon platform, these two experiments illustrate an excellent case study of volumetric and length scaling, keeping almost all other variables constant.

With a diameter increase of 23 percent and a length decrease of 29 percent, the gross behavior of the WRFMZY 5.56 is different than the 12-baffle 5.56 XL, but with regard to overall personnel risk, is relatively the same, on average. Back pressure is slightly reduced.  Gross suppression performance is almost identical.

PEW Science Research Note 9: Again, it is worth examining the above raw blast overpressure and impulse data, this time measured during the test of the WRMFZY 5.56:

  1. Blast load blowdown duration is again relatively long with bolt carrier group (BCG) returning to battery slightly later than with the 5.56 XL (Fig. 6a).

  2. Early precursors give way to internal combustion signature resonance from the 3D-printed body of the silencer with more initial volumetric expansion; initial coupled jetting remains extremely consistent (Fig. 6b).

  3. First-round-pop (FRP) divergence happens somewhat later, but still aggressively (Fig. 6 and Fig. 7). FRP momentum ramp is again severe in both accumulation rate and peak amplitude, in both pressure and impulse space, this time with more pronounced multi-stage flow.

  4. Post-FRP momentum throttle again consists of two primary phases. This time, the second phase becomes unstable. 

It is likely that volumetric expansion and manufacturing method result in the behavior observed in (2) and (3), with the behavior in (4) occurring due to there being less baffles in this silencer than the 5.56 XL.

Again, this technology is well studied.  Reducing baffle count will not meaningfully reduce back pressure until only few baffles remain, due to the early-time flow rate being fixed.  However, by increasing diameter and thus volumetric expansion, downstream suppression loss is reduced and overall signature suppression remains almost identical, despite the shorter length.  FRP remains significant.

The signatures measured at the shooter’s ear with the Tuna Cans WRMFZY 5.56 are presented and analyzed in the full Member Version of this report.

Comparison with the rest of the silencers in the M4 Rankings follows.

6.229.4 Suppression Rating Comparison (5.56x45mm from the M4A1)

Figure 10 presents a comparison of the PEW Science Suppression Ratings of the Tuna Cans 12-baffle 5.56 XL and WRMFZY 5.56 rifle silencers, with those of several other silencers on the M4A1 weapon system. The standard PEW Science M4A1 test host weapon system is described in Public Research Supplement 6.127.

Figure 10. Suppression Rating Comparisons of the Tuna Cans 5.56 XL, WRMZY 5.56, CAT ST, Otter Creek Labs OCM5, OCM6, Whiskey Quebec 5.56 Purged and Non-Purged, Wolfpack Armory Disruptor 556, Infinity, 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 10 presents an overall summary of the postulated hazards to the operator and bystanders when fielding the Tuna Cans 12-baffle 5.56 XL and WRMFZY 5.56 on the M4A1 weapon system (shown in red).  Data is also presented for the fielding cases of the CAT ST (6.217), Otter Creek Labs OCM5 and OCM6 (6.213), Battle Born Supply Co. Whiskey Quebec 5.56 series (6.206), Wolfpack Armory Disruptor 5.56 (6.199), 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:

  1. In pure muzzle suppression performance, the Tuna Cans silencers are competitive with several top performing models.  However, for the size, they are not as competitive.

  2. Operator protection with the Tuna Cans silencers is relatively low, but it is relatively low with all tested silencers on this host platform. Only the highest flow rate models can meaningfully reduce ejection port blast on this standard untuned host.

  3. Note that despite the similarity in shooter’s ear (operator) Suppression Rating with the Tuna Cans as some of the other silencers, the actual ejection port blast hazards with the Tuna Cans silencers are very severe due to very high back pressure, as shown in the raw blast overpressure and impulse waveforms measured at the operator’s head. The behavior is akin to that of an OCM5, Otter Creek Labs Polonium (6.75), SilencerCo Saker 5.56 (6.53), or original AAC M4-2000 (6.139) for example. System tuning is highly recommended to help mitigate this behavior.

PEW Science Research Note 11: As discussed earlier in this report, the technology in the Tuna Cans silencers is well studied.  With enough baffles and/or expansion volume, it produces significantly suppressed muzzle blast, with high back pressure, and severe FRP.  Because the baffle type in both silencers are so similar, and they are tested on the same weapon platform, these two experiments illustrate an excellent case study of volumetric and length scaling, keeping almost all other variables constant.  With a diameter increase of 23 percent and a length decrease of 29 percent, the gross behavior of the WRFMZY 5.56 is different than the 12-baffle 5.56 XL, but with regard to overall personnel risk, is relatively the same, on average. Back pressure is slightly reduced with the larger diameter and short length, but gross suppression performance is almost identical, on average.

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 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.

6.229.5 Review Summary: Tuna Cans 5.56 XL and WRMFZY 5.56 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 direct-thread mounted, the Tuna Cans 5.56 XL in the 12-baffle configuration  achieved a Suppression Rating™ of 41.0 in PEW Science testing.  With the same weapon system, mounted the same way, the Tuna Cans WRMZY 5.56 achieved a Suppression Rating of 41.3.

As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.

PEW Science Laboratory Staff Opinion:

The Tuna Cans 5.56 XL and WRMFZY 5.56 are full-size 5.56 silencers that use conventional technology to produce competitive pure muzzle blast suppression.  Both silencers are stainless steel, with the XL model possessing a modular baffle array and the WRMFZY silencer being 3D-printed, larger diameter, and shorter. The technology in the silencers is well studied; it offers scalable pure suppression performance with high back pressure and pronounced FRP.  These budget-friendly silencers, if used with reciprocating weapon systems, dictate the use of weapon tuning such that ejection port blast hazards may be reduced.

Tuna Cans 5.56 XL uses conventional straight-cone baffles with ridges to increase surface area and turbulence which both influence heat transfer and signature suppression.  The notched cones, arranged in the full 12-baffle array in the tested specimen, produce significant flow restriction throughout the time regime of combustion blowdown and throttle gas momentum to atmosphere to a significant degree.  In this 9.8-in long configuration, the silencer achieves relatively high signature suppression performance, on average, with high back pressure and FRP. The Tuna Cans WRMFZY 5.56 silencer uses the same baffle technology as present in the modular 5.56 XL silencer, in a non-modular 3D-printed configuration that is larger diameter but shorter. The baffle type is almost identical in that they are straight cones with ridged bodies; the baffle orifices, however, are alternating oblong shapes, instead of notched.

With a diameter increase of 23 percent and a length decrease of 29 percent, the gross behavior of the WRFMZY 5.56 is different than the 12-baffle 5.56 XL, but with regard to overall personnel risk, is relatively the same, on average. Back pressure is slightly reduced.  Gross suppression performance is almost identical.

The modular nature of the 5.56 XL can be exploited by using wrenches to remove baffles until an appropriate length and weight are achieved for the user’s purposes. Each baffle section weighs approximately 1.6 ounces; to compute the weight of a configuration with fewer baffles, you may subtract (1.6 x removed baffle number) from the total 29.5 ounce 12-baffle configuration weight. Similarly, length would be reduced by approximately 0.5-in per removed baffle. Using the silencer with no baffles would most likely result in a very severe signature. Using the silencer with half of the provided baffles would most likely reduce suppression performance with back pressure remaining high. Performance of the silencer with less than 12 baffles is outside the scope of this study. 

The user may adapt the silencers to a variety of mounting systems of their preference by taking advantage of the HUB-compatible rear threading.

In this review, the Tuna Cans 5.56 XL and WRMFZY 5.56 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.