SSS.6.220 - AAC 762-SDN-6 and the KAC SR-25 7.62x51mm 14.5-in Barrel Automatic AR-10 Rifle (Free Version)
/AAC 762-SDN-6 on the KAC 7.62x51mm SR-25 with 14.5-in Barrel
The 762-SDN-6 is distributed by Advanced Armament Company (AAC). It is a 30 caliber centerfire rifle silencer, intended to suppress most cartridges appropriately sized to travel through the bore. It has an outer diameter that varies from 1.62-in to 1.56-in and the silencer core is 7 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 tested third-party 3/4-24tpi direct-thread mount increased the system length to 7.41 inches. Other mounting options are possible due to the rear of the silencer body being HUB compatible (1.375-24 tpi threading).
The production retail version of the 762-SDN-6 silencer is DMLS (3D-printed) from Inconel alloy and includes a 1x16 LH HUB mount coupler and accompanying AAC Blackout flash hider. The use of that mounting system with the silencer results in a total length of 7.69 inches.
The silencer specimen evaluated in this test program is printed titanium. The core of the silencer weighs 10.3 ounces and the direct thread mount weighs 1.2 ounces, for a total system weight of 11.5 ounces, as tested. The Inconel production version of the silencer is reported to weigh 20.5 ounces and would therefore weigh approximately 21.7 ounces with the tested direct-thread mount. The AAC 762-SDN-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 8.1.17 for further details. The PEW-SOFT HD Blast Hazard Prediction Tool and Hazard Mapper is presented in Report 8.1.1.
AAC 762-SDN-6 14.5-in SR-25 AR-10 Free Field Hazard Map Produced by PEW-SOFT HD Blast Hazard Prediction Tool using PEW Science Test Data
Historical Note:
The original 762-SDN-6 was designed and manufactured by the original AAC (Advanced Armament Corporation) and debuted in 2011. The silencer weighed 20 ounces, was 7.66-in long without a mount, had a 1.5-in diameter, and mounted to AAC BLACKOUT 51-tooth ratcheting muzzle devices. The silencer had a fully-welded Inconel baffle stack inside the outer tube. It was intended to be used on cartridges ranging from 7.62 NATO to 5.56 NATO, including 300 AAC Blackout, 6.8 SPC and 6.5. The silencer was the successor to the longer 762-SD which possessed an Inconel blast baffle and stainless steel baffle stack. The materials, performance, and manufacturing methods were considered modern at the time of design and production and significantly influenced the silencer industry state of practice going forward. The new iteration of the silencer evaluated in this report is considerably more advanced than the legacy version of the silencer. Modern high fidelity laboratory evaluation of the legacy 762-SDN-6 is forthcoming.
PEW Science laboratory evaluations of legacy AAC silencers to date include:
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-AAC-137-001-25. Therefore, data pertaining to the 762-SDN-6 in this Sound Signature Review is published with the express written permission of Advanced Armament Company.
The testing and analysis presented in this Sound Signature Review are of the 762-SDN-6 on the KAC SR-25 Automatic AR-10 rifle, chambered in 7.62x51mm NATO with a 14.5-inch barrel. Lake City M80 149gr ammunition was used in the tests. The standard PEW Science KAC SR-25 test host weapon system is described in Public Research Supplement 6.210.
Section 6.220.1 contains AAC 762-SDN-6 test results and analysis.
Section 6.220.2 contains overall gross Suppression Rating comparisons of the AAC 762-SDN-6, CAT AKB, Rampart Range Suppression Carson 30, Dillon DRC308, and the unsuppressed KAC SR-25 automatic rifle.
Section 6.220.3 contains an article summary and PEW Science laboratory staff opinions.
Summary: When paired with the 14.5-in barrel KAC SR-25 and fired with Lake City M80 149gr ammunition, the AAC 762-SDN-6 achieved a composite Suppression Rating™ of 33.5 in PEW Science testing.
The supersonic .300 BLK performance of the AAC 762-SDN-6 is detailed in Sound Signature Review 6.221, in which it achieved a composite Suppression Rating of 68.9.
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.
6.220.1 AAC 762-SDN-6 Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the AAC 762-SDN-6 direct-thread mounted 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. AAC 762-SDN-6 Sound Metric Summary
6.220.1.1 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 AAC 762-SDN-6 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. AAC 762-SDN-6 7.62x51mm NATO 14.5-in SR-25 Automatic Rifle Muzzle Sound Pressure Signature
Fig 1b. AAC 762-SDN-6 7.62x51mm NATO 14.5-in SR-25 Automatic Rifle Sound Pressure Signature
Figure 2a. AAC 762-SDN-6 7.62x51mm NATO 14.5-in SR-25 Automatic Rifle Muzzle Sound Impulse Signature
Figure 2b. AAC 762-SDN-6 7.62x51mm NATO 14.5-in SR-25 Automatic Rifle Muzzle Sound Impulse Signature
Unlike the legacy 762-SDN-6 from Advanced Armament Corporation, the updated modern 762-SDN-6 from Advanced Armament Company is a hybrid design. Manufacturing methods have advanced considerably in the fifteen years since the debut of the legacy silencer; additive manufacturing, silencer combustion testing and analysis, and blast dynamics education have created an environment in which designers may take more efficient advantage of design envelopes. The silencer is roughly the same size as the legacy model and HUB-mount system compatible.
Like the previously evaluated CAT AKB (6.218), Dillon DRC308 (6.211), and Rampart Range Suppression Carson 30 (6.216), the AAC 762-SDN-6 hybrid design incorporates both high flow rate features and conventional geometries to control distal blast propagation while reducing adverse influence on weapon function. For an overview of the three primary classes of rifle silencer designs, the reader is encouraged to review PEW Science Research Supplement 6.169.
PEW Science Research Note 1: The internal design of the AAC 762-SDN-6 is staged; it is important to note that the first expansion (blast) chamber of the silencer possesses non-standard surface topology on the first reflector, and similar 3D-printed geometry continues throughout the remainder of the baffles. The blast chamber also possesses circumferential vents at the end of the blast baffle throat that initiate the first flow stage. Flow rate through the silencer is relatively high in early time and controlled in late time, though the termination of the primary and annular pressure staging with the distal vent array does seem to be efficient for gross flow, as observed in the above measured test data. In practical terms, this means that the new AAC 762-SDN-6 possesses a high gross flow rate, with low back pressure and yet still exhibits high performance signature suppression in multiple combustion regimes (with high pressure, long duration combustion and low pressure, short duration combustion). This is demonstrated both in this report and in the subsonic 300 BLK evaluation of the 762-SDN-6 (6.221).
PEW Science Research Note 2: The AAC 762-SDN-6 battle rifle suppression performance from the above test data is characterized by the following observations:
The AAC 762-SDN-6 produces relatively low amplitude and controlled free field blast overpressure propagation, with a relatively expedient blowdown duration (Fig. 1a).
Internal combustion and precursor signatures are extremely consistent and there is a momentary throttle after initial coupled jetting prior to the initial primary jet pulse. After initiation of the primary jet, significant momentum throttle begins (Fig. 2b).
First-round-pop (FRP) from the system exhibits limited abrupt early divergence but the rate of FRP momentum accumulation slows and then matches that of subsequent shots. (Fig. 2b).
Post-FRP blast load impulse accumulation rate is consistent until Shot 5 in the string when late-time jet momentum accelerates (Fig. 2b).
The behaviors in (1) and (2) indicate significantly advanced suppression performance. The 762-SDN-6 throttles pressure amplitude without significant back pressure. This is particularly important in the suppression of a short-barrel 7.62 NATO weapon system. The behavior in (3) indicates that the multiple pressure stages of the 762-SDN-6 are still quenching FRP to a reasonable degree. The behavior observed in (4) is somewhat unusual. It is hypothesized that the titanium construction of the test specimen may have resulted in some heat-affected efficiency losses later in the string. More research is needed to confirm this hypothesis.
PEW Science Research Note 3: Despite the FRP divergence and higher momentum accumulation noted above, engineering-level analysis indicates that bystanders may not be subjected to adverse risk during the first shot with the AAC 762-SDN-6 on this weapon system, relative to subsequent shots, on average. This is the case even when excluding Shot 5 from the computations. It is highly likely that the FRP momentum throttle described in (3), above, contributes to a less intense relative signature severity to bystanders during the first shot.
PEW Science Research Note 4: It is important to note that the early time flow rate of the AAC 762-SDN-6 is extremely high. During internal PEW Science testing on semiautomatic weapons using subsonic (low pressure) ammunition, weapon cycling proved difficult in some test scenarios. Further research is ongoing.
PEW Science Research Note 5: As tested, the length of the AAC 762-SDN-6 with the direct thread mount is approximately 7.4 inches. This is approximately one inch longer than the recently evaluated CAT AKB and 0.4 inches longer than the Rampart Range Suppression Carson 30. The performance of the 762-SDN-6 on this weapon system is somewhat higher than that of the Carson 30, and nominally higher than that of the CAT AKB. Though it is probable the 762-SDN-6 outperforms these silencers in low pressure subsonic ammunition suppression, it should be noted that the performance gap between it and the other silencers with high pressure supersonic suppression evaluated in this report is not high, especially considering its somewhat longer length. This is an important illustration of silencer performance variation across combustion regimes and silencer designs. Silencer performance does not always scale proportionally across combustion regimes. This means that a silencer may exhibit higher or lower performance than its peer(s) as the following parameters are varied:
Ammunition type (supersonic high pressure or subsonic low pressure)
Barrel length (short or long)
Host type (locked breech or reciprocating)
Performance scaling proportionality and nonlinearity will get more complex as silencer designs continue to advance. The aforementioned Carson 30, CAT AKB, and Dillon DRC308 are all staged hybrid designs and included in the gross performance comparison in Section 6.220.1.2 of this report.
PEW Science Research Note 6: In general, on this weapon system, the overall hazard fields produced by several of the recently evaluated silencers are somewhat similar, despite the discrete performance differences. The reader is encouraged to examine personnel hazards spatially using the Silencer Hazard Map Briefs in Section 8 of the Standard:
PEW Science Research Note 7: Using the Suppression Rating Parametric Visualization Tool (Members Only) and limiting the maximum tested system length to 7.41 inches, filtering for .308 ammunition, a significant number of silencer configurations are shown to compare with the AAC 762-SDN-6. With a muzzle Suppression Rating of 32.9, the 762-SDN-6 is the third highest performer in that metric, and the range of muzzle Suppression Ratings is 12 to 33.2, in that silencer length range on all 7.62 NATO rifle test hosts (including bolt-action). Preliminarily, it is postulated that the AAC 762-SDN-6 produces competitive signature suppression performance, for its size, in this combustion regime. The Liberty Precision Machine Anthem-S (6.79) is somewhat shorter than the AAC 762-SDN-6 but also has significantly higher back pressure than the 762-SDN-6. Its short barrel 7.62 NATO combustion suppression has not yet been evaluated. It is extremely important to note that the blast overpressure input from a 20-in barrel 7.62 NATO system and 14.5-in barrel 7.62 NATO system are significantly different.
PEW Science Research Note 8: As in all semiautomatic rifle 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 97 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 9: The closing time of automatic rifle bolts is often 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 10: Note that the muzzle Suppression Rating of the AAC 762-SDN-6 is 32.9 and the at-ear Suppression Rating is 22.4; different zones on the Suppression Rating Dose Chart. In the tested configuration, the blast loads from the tested weapon system are significantly suppressed, but not suppressed enough for a human to forgo the use of hearing protection, for most use operator use cases. However, use of the AAC 762-SDN-6 silencer on the SR-25, when compared to firing the SR-25 unsuppressed, may significantly reduce the risk of blast overpressure injuries, such as traumatic brain injury (TBI), particularly near reflecting surfaces.
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 SR-25 weapon system are compared in the following section.
6.220.2 Suppression Rating Comparison (7.62x51mm from the 14.5-in SR-25)
Figure 5 presents a comparison of the PEW Science Suppression Ratings of the AAC 762-SDN-6 with that of the CAT AKB, Rampart Range Suppression Carson 30, Dillon DRC308, and the unsuppressed KAC SR-25 weapon system. The standard PEW Science SR-25 test host weapon system is described in Public Research Supplement 6.210. As PEW Science research with the KAC SR-25 system continues, the dataset will be further populated.
Figure 5. Suppression Rating Comparisons of the Suppressed and Unsuppressed 14.5-in KAC SR-25, 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 the AAC 762-SDN-6, CAT AKB, Rampart Range Suppression Carson 30, and the Dillon DRC308 on the 14.5-in KAC SR-25 weapon system with a direct-thread mount. Data is also presented for the fielding case of the unsuppressed KAC SR-25. 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.
As previously discussed in Research Note 4, the early time flow rate of the AAC 762-SDN-6 is extremely high. During internal PEW Science testing on semiautomatic weapons using subsonic (low pressure) ammunition, weapon cycling proved difficult in some test scenarios. Research is ongoing. For a silencer with that high of a flow rate, the above suppression performance is extremely notable.
As previously discussed in Research Note 7, with a muzzle Suppression Rating of 32.9, the 762-SDN-6 is the third highest performer in that metric, and the range of muzzle Suppression Ratings is 12 to 33.2, in that silencer length range on all 7.62 NATO rifle test hosts (including bolt-action). Preliminarily, it is postulated that the AAC 762-SDN-6 produces competitive signature suppression performance, for its size, in this combustion regime. Its higher muzzle suppression performance potential with its very high early time flow rate allow it to surpass the overall signature reduction performance of the Rampart Range and Dillon silencers at both the operator and bystander locations and nominally outperform the bystander signature reduction performance of the shorter CAT AKB.
It is also extremely important to note that the blast overpressure input from a 20-in barrel 7.62 NATO system and 14.5-in barrel 7.62 NATO system are significantly different. Furthermore, it is also important to note that the Carson 30 is intended for automatic (reciprocating) rifle use; not bolt-action rifle use. Therefore, its flow rate and blast load input bias are optimized for the host weapon type in this test program, not for longer barrel locked breech weapons. As it stands, the AAC 762-SDN-6 significantly reduces operator hazard when compared to the fielding of an unsuppressed 14.5-in barrel SR-25. Short barrel 7.62 NATO weapons are significantly hazardous to personnel. It is is important to note that blast overpressure may damage not only a human’s ears, but a human’s brain. Suppressed shooting is highly recommended.
It is highly likely, though not yet verified, that the operator protection, and also potentially the bystander protection, showcased by the new AAC 762-SDN-6 is significantly more robust than the higher back pressure legacy 762-SDN-6. Future research will examine this performance comparison.
The new AAC 762-SDN-6 possesses a high gross flow rate, with low back pressure and yet still exhibits high performance signature suppression in multiple combustion regimes (with high pressure, long duration combustion and low pressure, short duration combustion). This is demonstrated both in this report and in the subsonic 300 BLK evaluation of the 762-SDN-6 (6.221).
PEW Science Research Note 14: Several silencers possessing hybrid design traits are expected to exhibit performance differentials on the standard 20-in .308 bolt-action and 14.5-in SR-25 test host weapon systems. PEW Science urges extreme caution when attempting to extrapolate the performance of a silencer on either of these weapon systems to the other without instrumented test data and engineering analysis. Performance differentials may be counterintuitive due to the complexities of hybrid 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 automatic rifle; all other things equal. For details on performance increases that are possible when “tuning” an automatic 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 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.
6.220.3 Review Summary: AAC 762-SDN-6 on the KAC 7.62x51mm SR-25 with 14.5-in Barrel
When paired with the 14.5-in barrel KAC SR-25 and fired with Lake City M80 149gr ammunition, the AAC 762-SDN-6 achieved a composite Suppression Rating™ of 33.5 in PEW Science testing.
The supersonic .300 BLK performance of the AAC 762-SDN-6 is detailed in Sound Signature Review 6.221, in which it achieved a composite Suppression Rating of 68.9.
As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.
PEW Science Laboratory Staff Opinion:
The AAC 762-SDN-6 is a midsize 30 caliber rifle silencer with significantly high suppression performance and flow rate. The silencer is an updated modern iteration of the legacy version that originally debuted in 2011. The new silencer is a hybrid design; manufacturing methods have advanced considerably in the fifteen years since the debut of the legacy silencer. Additive manufacturing, silencer combustion testing and analysis, and blast dynamics education have created an environment in which designers may take more efficient advantage of design envelopes. The silencer is roughly the same size as the legacy model and HUB-mount system compatible. The new 762-SDN-6 is constructed from 3D-printed Inconel alloy.
The internal design of the AAC 762-SDN-6 is staged; it is important to note that the first expansion (blast) chamber of the silencer possesses non-standard surface topology on the first reflector, and similar 3D-printed geometry continues throughout the remainder of the baffles. The blast chamber also possesses circumferential vents at the end of the blast baffle throat that initiate the first flow stage. Flow rate through the silencer is relatively high in early time and controlled in late time; the gross flow is very efficient, as observed in the above measured test data. In practical terms, this means that the new AAC 762-SDN-6 has low back pressure and yet still exhibits high performance signature suppression in multiple combustion regimes (with high pressure, long duration combustion and low pressure, short duration combustion). This is demonstrated both in the subject report and in the subsonic 300 BLK evaluation of the 762-SDN-6.
The early time flow rate of the AAC 762-SDN-6 is extremely high. During internal PEW Science testing on semiautomatic weapons using subsonic (low pressure) ammunition, weapon cycling proved difficult in some test scenarios. Research is ongoing. For a silencer with that high of a flow rate, its achieved suppression performance is extremely notable.
With a muzzle Suppression Rating of 32.9, the 762-SDN-6 is the third highest performer in that metric, and the range of muzzle Suppression Ratings is 12 to 33.2, in the silencer length range on all 7.62 NATO rifle test hosts (including bolt-action). Preliminarily, it is postulated that the AAC 762-SDN-6 produces competitive signature suppression performance, for its size, in this combustion regime. Its higher muzzle suppression performance potential with its very high early time flow rate allow it to surpass the overall signature reduction performance of the Rampart Range and Dillon silencers at both the operator and bystander locations and nominally outperform the bystander signature reduction performance of the shorter CAT AKB.
It is highly likely, though not yet verified, that the operator protection, and also potentially the bystander protection, showcased by the new AAC 762-SDN-6 is significantly more robust than the higher back pressure legacy 762-SDN-6. Future research will examine this performance comparison.
The user may choose to field the Inconel 762-SDN-6 silencer with a variety of mounting systems of their preference. The silencer includes a 1x16 LH HUB mount coupler and accompanying AAC Blackout flash hider. The use of that mounting system with the silencer results in a total length of 7.69 inches. The 7.4-inch long tested system used with a third-party direct-thread mount as the KAC SR-25 is threaded 3/4-24tpi (different from the common 5/8-24tpi of many 30 caliber systems).
Several silencers possessing hybrid design traits are expected to exhibit performance differentials on the standard 20-in .308 bolt-action and 14.5-in SR-25 test host weapon systems. PEW Science urges extreme caution when attempting to extrapolate the performance of a silencer on either of these weapon systems to the other without instrumented test data and engineering analysis. Performance differentials may be counterintuitive due to the complexities of hybrid systems’ response to varying blast load input pressure(s) and duration(s).
In this review, the AAC 762-SDN-6 performance metrics depend upon suppressing a supersonic centerfire rifle cartridge on a short barrel gas-operated 7.62 NATO 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 7.62x51mm 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.
