SSS.6.161 - Savage Arms AccuCan AC30 and the Savage Model 10 PC .308 (Free Version)
/Savage Arms AccuCan AC30 on a Savage Model 10 .308 with 20-in Barrel
The AccuCan AC30 is distributed by Savage Arms. It is a 30 caliber centerfire rifle silencer, intended to suppress many cartridges with projectiles appropriately sized to travel through the bore, including 300 Winchester Magnum. It has a 1.75-inch diameter and is 7.9 inches in length, including its integrated direct-thread mount. The silencer mount is aluminum with a titanium thread insert, whereas the monolithic baffle stack and tube are 7075-T6 aluminum. The silencer is able to be disassembled, may be installed on host weapons threaded 5/8”-24tpi, and weighs 10.8 ounces, as tested. The AccuCan AC30 can be obtained from Savage Arms Dealers.
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 for public research is generated with funding provided by PEW Science members. Any test data and analysis 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-SAVAGE-083-001-24. Therefore, data pertaining to the AccuCan AC30 in this Sound Signature Review is published with the express written permission of Savage Arms LLC.
This review contains single test results using the AccuCan AC30 direct-thread mounted on the Savage Model 10 Precision Carbine rifle, chambered in .308WIN with a 20-inch barrel. Federal XM80 149gr ammunition was used in the test.
- Section 6.161.1 contains the AccuCan AC30 test results and analysis.
- Section 6.161.2 contains back pressure and Suppression Rating comparisons with selected .30 rifle silencers possessing a PEW Science Back Pressure Metric, Ω [Pa-1] in Omega Zone 5 and below. An updated Ω metric chart for the full suite of publicly evaluated .30 rifle silencers is also provided in this section. Further information about the Ω metric and Omega Zones can be obtained in PEW Science Research Supplement 6.40 (Public Article).
- Section 6.161.3 contains the review summary and PEW Science laboratory staff technical opinions.
Summary: When paired with the Savage M10 20” .308 and fired with Federal XM80, the direct-thread mounted Savage Arms AccuCan AC30 achieved a Suppression Rating™ of 35.3 in PEW Science testing.
As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.
Relative Suppression Rating Performance is Summarized in SSS.7 - PEW Science Rankings
6.161.1 Savage Arms AccuCan AC30 Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the AccuCan AC30 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. Savage Arms AccuCan AC30 Sound Metric Summary
6.161.1.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories acquired with PEW-SOFT™ are shown below. The waveforms are not averaged, decimated, or filtered. The data acquisition rate used in all PEW Science 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 testing; the industry leader in silencer sound research. For more information, please consult the Silencer Sound Standard.
The primary sound signature pressure histories for all 5 shots with the AccuCan AC30 are shown in Figure 1a. The sound signatures of Shot 1, Shot 2, and Shot 3 are shown in Figure 1b, in early time. The real sound impulse (momentum transfer potential) histories from the same 5-shot test are shown in Figure 2a. In Figure 2b, a shorter timescale is shown comparing the impulse of the first three shots.
Fig 1a. Savage Arms AccuCan AC30 Bolt Action Rifle Muzzle Sound Pressure Signature
Fig 1b. Savage Arms AccuCan AC30 Bolt Action Rifle Muzzle Sound Pressure Signature, Short Time Window
Figure 2a. Savage Arms AccuCan AC30 Bolt Action Rifle Muzzle Sound Impulse Signature
Figure 2b. Savage Arms AccuCan AC30 Bolt Action Rifle Muzzle Sound Impulse Signature, Short Time Window
Figure 1b shows a 1.8 millisecond long portion of the sound pressure signatures of the first three rounds fired from the Savage Arms AccuCan AC30, as measured 1.0 m left of the muzzle. There are several significant waveform features labeled:
Internal combustion within the silencer is relatively consistent and reaches a peak of 123.8 dB.
The end cap exit event, consisting of bullet shock and the initial jet, results in a peak overpressure magnitude of 140.6 dB.
Primary first-round-pop (FRP) jetting occurs early, diverging from normalized flow with maximum primary jetting occurring prior to that of subsequent shots.
Subsequent shots exhibit more normalized flow with pronounced secondary jetting typical of all shots in the string.
This is a somewhat typical sequence observed when firing supersonic .308WIN ammunition from a bolt-action rifle with an attached silencer that exhibits relatively low to moderate flow restriction (back pressure). Internal silencer design can significantly influence the measured timing and pressure amplitudes. Preliminary back pressure comparisons are shown in Section 6.161.3 of this review, with the PEW Science Back Pressure Metric, Ω [Pa-1]. Note that weapon system influence is a function of both Ω and early-time wave propagation factors which may be measured inside the system, in close proximity to the muzzle orifice. These factors include the PEW Science alpha parameter; a subject of internal research.
The AccuCan AC30 is a relatively lightweight silencer, and like the previously evaluated Savage Arms AccuCan AC22 (6.154), possesses a somewhat traditional monolithic baffle core (monocore) design. Like the AC22, the AC30 monocore uses washer-type geometry. However, unlike the AC22, the AC30 uses a cone-throat blast baffle rather than flat plate reflector. Again, progressively increasing volumetric cavities from proximal to distal end, along with relatively high thermal conductivity of its primarily aluminum construction, enable higher suppression efficiency in the tested combustion pressure regime than is typically seen from this type of monocore design. The 7.9 inch length of the AccuCan AC30 does assist with its suppression performance.
The examination of the performance of both the AC22 and AC30 provides insights into how a single silencer technology may be adapted for use in different combustion regimes, and the potential strengths and limitations of such adaptation. For example, in addition to efficient heat transfer, the aluminum construction of such systems also provides significant weight savings and the volumetric expansion in each design also improves efficiency. However, as subsonic rimfire combustion propagation differs significantly from supersonic centerfire rifle loading, the impact of increased volume on performance, in each design, is much different. As both pressure and duration of silencer load input increase, suppression of the output signature becomes progressively more challenging. Volumetric expansion is only one mechanism of signature suppression.
PEW Science Research Note 1: The Savage AC30 does exhibit measurable FRP on this host weapon platform, in both pressure space (Figure 1) and impulse space (Figure 2). The severity differential between the first shot and subsequent shots, to bystanders, may be as great as approximately 20%. In this particular design, this phenomena is partially due to the aforementioned significant volumetric expansion in chambers which have relatively featureless geometry. Nonetheless, after FRP, combustion propagation normalizes and consistency is noted in both blast momentum accumulation and maxima (Fig. 2b). Notable consistency is observed through the first exit event in the coupled jet shown at approximately 29.5 ms in pressure space (Fig. 1b).
PEW Science Research Note 2: As the Silencer Sound Standard research pedigree includes the evaluation of a variety of technologies on this host weapon system, it is interesting to compare the efficacy of a somewhat legacy monocore design with that of modern offerings. Using the Member Suppression Rating Parametric Visualization tool, there are three other silencers tested in the pedigree at or below the length and weight of the Savage AC30; the YHM Resonator K (6.32), the Dead Air Nomad Ti (6.44), and the Diligent Defense Enticer S-Ti (6.68). The AC30 is outperformed by the Nomad Ti and Enticer S-Ti, as those silencers possess significantly more complex baffle geometry with purposely induced stagnation relief zones efficiently optimized for high pressure flow. The muzzle Suppression Rating of the AC30 is in the same zone on the Dose Chart as those two silencers, and the shooter’s ear Suppression Rating is approximately half a category lower. This difference in spatial severity of the pressure fields produced by all three systems demonstrate the impact of technological advancement in the state of practice and how legacy designs compare in modern systems.
When moving immediately outside the length and weight envelope, silencers like the Rugged Radiant (6.12), Dead Air Sandman-S (6.11), and Q Trash Panda (6.4), can be compared. These three silencers, all shorter than the AC30, are outperformed by the simple monocore design. Commonalities between the three models include cone baffles of varying geometry with no purposely-induced stagnation relief for high pressure flow. Again, these performance benchmarks illustrate technological progression in the state of practice with meaningful and dimensional factors for comparison, in context. Despite the rapid pressurization of large volumetric stages of the AC30 internal geometry, its legacy design is able to outperform these silencers. Volumetric expansion and length, in this case, outweigh the need for advanced technology. It is important to note that such a conclusion does not always hold for various designs, and also does not allow for the minimization of silencer size.
PEW Science Research Note 3: The relatively rapid rise to maximum peak positive phase impulse displayed in Figure 2 results in an accumulation rate from the silencer that places it in Omega Zone 4 (ref. 6.40). It is important to note that the Savage AccuCan AC30, should not be considered a “low back pressure” rifle silencer, relative to higher flow rate models on the market (i.e. HUXWRX, PTR, CAT, Surefire RC3, SilencerCo Velos, etc.)
Again, consistent with the above measured pressure and impulse waveform features, the computed PEW Science Omega Metric is relatively low to moderate, placing the silencer in Omega Zone 4. Relative Suppression Rating and flow restriction (back pressure) data is presented in Section 6.161.2 of this review.
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 has made a concerted effort to characterize the FRP phenomenon with true physiological human inner-ear response analyses. Additional PEW Science Member Research Supplements containing this information are released periodically.
6.161.2 Relative Suppression Rating and Back Pressure Comparisons (.30 Rifle Silencers)
The Savage Arms AccuCan AC30 suppressor is intended to offer competitive sound signature suppression in a lightweight envelope without regard to flow restriction (back pressure). To characterize gross flow rate, PEW Science has developed an empirical relation to quantify the back pressure (flow restriction) of silencers. Figure 5 and Figure 6 show supersonic suppression and back pressure comparisons between selected 7.62mm (30 caliber) rifle silencers shown in public PEW Science Sound Signature Reviews, as of the date of this review publication. The results shown in Figure 5 and Figure 6 are calculated from real test data acquired with PEW-SOFT. Please note the following:
The PEW Science Back Pressure Metric, Ω [Pa-1], may be generated for any silencer and suppressed weapon system using any suitable raw external overpressure signature data acquired 1.0 m left of the silencer end cap. PEW Science highly recommends data acquisition in accordance with The Silencer Sound Standard.
Omega Zones are presented in Table 3, below, which are intended to provide guidance to weapons developers, silencer designers, and end-users, with regard to flow restriction characteristics of different silencer designs. It is very important to note that silencers possessing a relatively high Ω can still provide functional use on weapon systems. Some weapon systems are more sensitive to Ω than others.
It is important to note that a silencer’s Omega Zone can shift when using a mounting scheme that differs from that used in the testing referenced in the published PEW Science Sound Signature Reviews. This phenomenon occurs due to some silencer mounting schemes significantly influencing flow restriction with some silencer designs.
The theoretical lower limit of flow restriction, or so-called "zero back pressure" would be represented by the unsupressed state, Ω = 0 [Pa-1].
PEW Science acknowledges that other dynamic events occur within a suppressed weapon system that can also influence weapon function. Therefore, PEW Science acknowledges that Ω is not the sole parameter one must consider for total supppressed weapon system operation. However, PEW Science postulates that the Ω metric influence can be significant. Note that weapon system influence is also a function of early-time wave propagation factors which may be measured inside the system, in close proximity to the muzzle orifice. These factors include the PEW Science Alpha parameter; a subject of internal research.
The Back Pressure Metric relations are most easily viewed on a logarithmic scale (See Figure 6).
Figure 5. Omega Back Pressure Metric And Suppression Rating Comparisons Of .308 Rifle Silencers Using PEW-SOFT Data and Analysis
As stated above, the PEW Science Back Pressure Metric is most easily viewed on a logarithmic scale. The metric is nonlinear; the shape of the trend in the data presented in Figure 6, below, illustrates the potential thresholds of extreme flow rate (approaching the unsuppressed state) and extreme flow restriction (approaching the trapping of the maximum amount of combustion byproducts in a system).
Figure 6. Omega Back Pressure Metric Comparisons Of .308 Rifle Silencers Using PEW-SOFT Data and Analysis
Omega characterizes silencer back pressure. It is important to note that back pressure is not blow back. The back pressure of a silencer is the flow restriction it introduces in a suppressed weapon system. The blow back phenomenon that can occur during the use of a suppressed weapon system is caused by the reciprocating system actuating too early relative to overpressure decay within the weapon system, resulting in exposure of excessive internal system overpressure to atmosphere. Some weapons may be tuned to function well with silencers in a high Omega Zone. Some weapons may require low-Omega silencers due to constraints in their operating system(s). Omega metric technical details can be found in PEW Science Public Research Supplement 6.40.
Table 3. PEW Science Back Pressure Metric Omega Zones And Suppressed Weapon System Functional Descriptions
As stated above, weapon system influence is a function of both Ω and early-time wave propagation factors which may be measured inside the system, in close proximity to the muzzle orifice. These factors include the so-called PEW Science Alpha parameter; a subject of internal research. The Savage AC30 was tested with its integrated direct-thread mount which does not significantly influence early time shock reflections near the muzzle. Mount geometry, chamber geometry, and the blast baffle shape all contribute to early-time flow restriction, in addition to late-time flow restriction characterized by Omega. The monocore geometry of the AC30 does include a curved cone blast baffle that will undoubtedly influence early-time blast load reflections differently than geometry integrated into purpose-built early venting models.
As noted in the preceding section, it is interesting to compare the efficacy of a somewhat legacy monocore design with that of modern offerings. There are three other silencers tested in the pedigree at or below the length and weight of the Savage AC30; the YHM Resonator K (6.32), the Dead Air Nomad Ti (6.44), and the Diligent Defense Enticer S-Ti (6.68). The AC30 is outperformed by the Nomad Ti and Enticer S-Ti, as those silencers possess significantly more complex baffle geometry with purposely induced stagnation relief zones efficiently optimized for high pressure flow. The muzzle Suppression Rating of the AC30 is in the same zone on the Dose Chart as those two silencers, and the shooter’s ear Suppression Rating is approximately half a category lower. This difference in spatial severity of the pressure fields produced by all three systems demonstrate the impact of technological advancement in the state of practice and how legacy designs compare in modern systems.
When moving immediately outside the length and weight envelope, silencers like the Rugged Radiant (6.12), Dead Air Sandman-S (6.11), and Q Trash Panda (6.4), can be compared. These three silencers, all shorter than the AC30, are outperformed by the simple monocore design. Commonalities between the three models include cone baffles of varying geometry with no purposely-induced stagnation relief for high pressure flow (see previous discussion in Research Note 2).
PEW Science Research Note 5: Moving to comparisons with other silencers specifically shown in Figure 5, the AC30 produces an operator hazard in the free field that is somewhat similar to the HUXWRX (OSS) HX-QD 7.62 (6.41). This comparison demonstrates how two significantly different technologies can produce the same severity to personnel at a location in the sound field, despite managing combustion products in completely different ways. Whereas the HX-QD system provides immediate and continuous gas expansion through lengthened flow paths maximizing continuous turbulence and surface area interaction for heat transfer, the legacy-type monocore design of the AC30 relies on “brute force” volumetric expansion to achieve similar goals. Different diameter, length, and technological implementations may produce similar high-level results when strictly considering operator hazard. Due to the breadth of the Silencer Sound Standard testing and analysis pedigree, the reader is encouraged to examine the spectrum over which suppression performance on bolt-action weapon systems has been demonstrated. There exist silencers evaluated on the 7.62x51mm NATO rifle platform that have significantly lower performance. Because the PEW Science Suppression Rating is a damage risk criterion (DRC), a lower Suppression Rating indicates a higher personnel hazard in the free field. Therefore, such silencers are postulated to be more hazardous to the unprotected ear than silencers like the Savage Arms AccuCan AC30. To iterate, the Suppression Rating is a DRC - it is not a subjective quantity; it is an objective quantification of hearing damage risk potential.
PEW Science urges the reader not to misconstrue a low Omega metric with the mirroring of unsuppressed weapon function, nor a high Omega Metric with absolute use prohibition on semi-automatic systems. Each weapon system may experience varying sensitivity to different Omega Zones and users may exhibit varying preference for weapon system function and operability. The Zones are provided by PEW Science to assist the reader with determination of postulated applicability of silencer types, as some users may only have experience with certain silencers. The Omega Metric is one performance indicator; it allows overall flow rate phenomena to be categorized independently from sound signature suppression performance. Note that weapon system influence is also a function of early-time wave propagation factors which may be measured inside the system, in close proximity to the muzzle orifice.
It is extremely important to note that peak sound pressure [dB], peak sound impulse [dB-ms], and Omega (Ω) [Pa-1], alone, do not determine the sound supression performance of a silencer. It is the combination of these and other waveform parameters that form the total sound signature and the influence on human inner ear response. The PEW Science Suppression Rating computation considers all of these factors.
6.161.3 Review Summary: Savage Arms AccuCan AC30 on a Savage Model 10 .308 with 20-in Barrel
When paired with the Savage M10 20” .308 and fired with Federal XM80, the direct-thread mounted Savage Arms AccuCan AC30 achieved a Suppression Rating™ of 35.3 in PEW Science testing.
As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.
PEW Science Laboratory Staff Opinion:
The Savage Arms AccuCan AC30 is a full-size lightweight 7.62mm rifle silencer that is designed for bolt-action rifle use. The AC30 is user-serviceable, possesses a built-in direct-thread mount, and is lighter than many silencers in its class. The monolithic baffle core technology in the AccuCan AC30 is relatively efficient given that the 7075 aluminum construction allows significant volumetric expansion without a significant weight penalty.
The AccuCan AC30 weighs 10.8 ounces, and like the previously evaluated Savage Arms AccuCan AC22, possesses a somewhat traditional monolithic baffle core (monocore) design. Like the AC22, the AC30 monocore uses washer-type geometry. However, unlike the AC22, the AC30 uses a cone-throat blast baffle rather than flat plate reflector. Again, progressively increasing volumetric cavities from proximal to distal end, along with relatively high thermal conductivity of its primarily aluminum construction, enable higher suppression efficiency in the tested combustion pressure regime than is typically seen from this type of monocore design. The 7.9 inch length of the AccuCan AC30 does assist with its suppression performance.
There are three other silencers tested in the pedigree at or below the length and weight of the Savage AC30; the YHM Resonator K, the Dead Air Nomad Ti, and the Diligent Defense Enticer S-Ti. The AC30 is outperformed by the Nomad Ti and Enticer S-Ti, as those silencers possess significantly more complex baffle geometry with purposely induced stagnation relief zones efficiently optimized for high pressure flow. The muzzle Suppression Rating of the AC30 is in the same zone on the Dose Chart as those two silencers, and the shooter’s ear Suppression Rating is approximately half a category lower. This difference in spatial severity of the pressure fields produced by all three systems demonstrate the impact of technological advancement in the state of practice and how legacy designs compare in modern systems.
Immediately outside the length and weight envelope, silencers like the Rugged Radiant, Dead Air Sandman-S, and Q Trash Panda, can be compared. These three silencers, all shorter than the AC30, are outperformed by the simple monocore design. Commonalities between the three models include cone baffles of varying geometry with no purposely-induced stagnation relief for high pressure flow. Again, these performance benchmarks illustrate technological progression in the state of practice with meaningful and dimensional factors for comparison, in context. The AC30 produces an operator hazard in the free field that is somewhat similar to the HUXWRX (OSS) HX-QD 7.62. This comparison demonstrates how two significantly different technologies can produce the same severity to personnel at a location in the sound field, despite managing combustion products in completely different ways.
The direct-thread mount in the AccuCan AC30 is integrated into the silencer. The silencer is intended for bolt-action use; as a hunting silencer, for example, it is expected that it may be installed on the firearm and used in the field as-is. If attachment/removal of the silencer is necessary, wrench-flats are present on the mount for secure installation in the field.
The Savage AC30 is also user-serviceable. The main tube may be removed from the mount and core assembly with a bench vise and wrench tools. The user is encouraged to contact Savage Arms with questions or needs for assistance with any maintenance activities.
In this review, the AccuCan AC30 performance metrics depend upon suppressing a supersonic centerfire rifle cartridge; no easy 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 .308WIN cartridge are significant; the measured pressure and impulse magnitudes, and their durations, illustrate this fact.
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.
