SSS.6.154 - Savage Arms AccuCan AC22 and the CZ 452 .22 Bolt-Action
/Savage Arms AccuCan AC22 on a CZ 452 .22 Bolt Action with 16-in Barrel
The AccuCan AC22 is distributed by Savage Arms. It is a lightweight 22 caliber rimfire silencer intended to suppress cartridges ranging from .22 LR to .22 WMR. It is approximately 1 inch in diameter and is 5.9 inches long. The silencer mount is titanium, whereas the monolithic baffle stack and tube are 7075-T6 aluminum. The silencer is able to be disassembled and may be installed on host weapons threaded 1/2”-28tpi. In this test, an adapter was used to convert the native host weapon threads from 1/2”-20tpi. The silencer weighs 3.3 ounces, as tested. The AccuCan AC22 can be obtained from Savage Arms Dealers.
Errata: In the initial publication of this article, the measured tested weight of the AC22 was listed as 2.8 ounces, which was in error. The correct tested weight of the AC22 is 3.3 ounces.
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 that is generated with any portion of private funding contains this disclosure. The testing and data production for this Sound Signature Review white paper was funded in part by PEW Science Project PEW-SAVAGE-083-001-24. Therefore, data pertaining to the AccuCan AC22 in this Sound Signature Review is published with the express written permission of Savage Arms LLC.
This Sound Signature Review contains single-test results using the Savage AccuCan AC22 mounted to the CZ 452 American bolt-action rifle, chambered in .22LR with a 16-inch barrel. CCI Standard Velocity 40gr ammunition was used in the test.
Section 6.154.1 contains the Savage Arms AccuCan AC22 test results and analysis.
Section 6.154.2 contains Suppression Rating comparisons with selected .22 rimfire silencers in the subsonic ammunition combustion regime.
Section 6.154.3 contains the review summary and PEW Science laboratory staff technical opinions.
Summary: When paired with the CZ 452 American bolt-action rifle and fired with CCI SV .22 LR ammunition, the Savage Arms AccuCan AC22 achieved a composite Suppression Rating™ of 94.5 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
6.154.1 Savage Arms AccuCan AC22 Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Savage Arms AccuCan AC22 is shown in Table 1. The data acquired 1.0 m (39.4 in) left of the muzzle is available for viewing to all. This is a members-only review and includes pressure and impulse waveforms measured at the shooter’s ear. PEW Science thanks you for your support; further testing, research, and development of PEW-SOFT and the Silencer Sound Standard is made possible by members like you!
Table 1. Savage Arms AccuCan AC22 Sound Metric Summary
6.154.1.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 5-shot test acquired with PEW-SOFT™ are shown below. 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 5 shots are shown in Figure 1a. A zoomed-in timescale displays the region of peak sound pressure in Figure 1b, for the first two shots. The real sound impulse (momentum transfer potential) histories from the same 5-shot test are shown in Figure 2. Again, full and short timescales are shown.
Fig 1a. Savage Arms AccuCan AC22 Subsonic .22 LR Bolt Action Muzzle Sound Pressure Signature
Fig 1b. Savage Arms AccuCan AC22 Subsonic .22 LR Bolt Action Muzzle Sound Pressure Signature, Short Time Window
Figure 2a. Savage Arms AccuCan AC22 Subsonic .22 LR Bolt Action Muzzle Sound Impulse Signature
Figure 2b. Savage Arms AccuCan AC22 Subsonic .22 LR Bolt Action Muzzle Sound Impulse Signature
The Savage Arms AccuCan AC22 is an extremely lightweight silencer with a somewhat traditional monolithic baffle core (monocore) design. In the AC22 monocore, washer-type geometry is used, with a flat blast baffle plate and progressively increasing volumetric cavities from proximal to distal end. The progressive volumetric chamber increases along the almost 6-inch length envelope of the AC22, along with the relatively high thermal conductivity of its primarily aluminum construction, enable high suppression efficiency in the tested combustion pressure regime.
On long fixed-barrel host weapons producing low combustion pressure with the tested ammunition, such as the bolt-action rifle used in this test, the Savage Arms AccuCan AC22 provides very high suppression performance. The AC22 is able to outperform some other high-performance silencers such as the Rugged Oculus (6.1), the Mercy Firearms Pluto (6.146), and the Resilient Suppressors Jessie’s Girl (6.125). Several notable performance attributes of the AC22 are observed in the measured test data:
Extremely low primary muzzle blast jet pressure amplitude, consistently, from shot to shot (Fig. 1a).
Nominal first-round-pop (FRP) in both pressure and impulse space (Fig. 1b and Fig. 2b, respectively).
Consistent gas momentum transfer potential at maximum flow (Fig. 2).
PEW Science Research Note 1: As noted above, the Savage AC22 exhibits nominal measurable FRP on this host weapon platform, but the severity differential between the signatures of FRP and subsequent shots is minimal to non-existent. As typical at these levels of muzzle Suppression Rating, it is postulated that some bystanders may be able to discern a differential in signature, but the risk profile variation to bystanders is negligible, in accordance with PEW Science analysis.
PEW Science Research Note 2: Below certain pressure amplitude thresholds, high Suppression Rating performance potentials are more significantly influenced by blast wave shape factors (Research Note 3, 6.149, OCL Titanium). At very low amplitudes, these shape factors still influence response and as blast wave propagation significantly nests with acoustic wave phenomena, long duration jetting produces more negligible influence on bystander risk. The characteristic signature produced by the AC22 on this weapon system is somewhat similar to that produced by the CAT SR (6.140) in that regard, albeit less controlled.
PEW Science Research Note 3: The Savage Arms AccuCan AC22 is not a “low backpressure” system, and higher pressure semiautomatic system characterization has not yet been performed with this silencer. Performance differentials in such an application are the subject of future PEW Science research. It should be noted that initial conditions at the weapon muzzle significantly influence rimfire silencer suppression performance; the states of bullet uncorking from a 16-in barrel and 4-in barrel, for example, produce differing holistic signature behavior. The reader is encouraged to examine the PEW Science Rankings page which illustrates some of these potential performance differentials. Note that ejection port blast load from autoloading systems is an additional variable of concern.
The rimfire silencer performance Rankings are now expanding; the Savage Arms AccuCan AC22 joins the Otter Creek Labs Titanium, the Mercy Firearms Pluto, the CAT SR, the Resilient Suppressors Jessie’s Girl, and the Rugged Oculus in both its configurations in the current published dataset. In addition to bolt-action rifle evaluation, some of these silencers have also been evaluated on the subcompact semiautomatic Beretta 21A rimfire pistol. Additional evaluations in the rimfire ammunition combustion regime by PEW Science are forthcoming.
PEW Science Research Note 4: To iterate the above, users should note that performance of rimfire silencers on long and short barrels may be significantly different, even with subsonic ammunition, depending on silencer design.
6.154.1.2 SOUND SIGNATURES AT SHOOTER’S EAR
Real sound pressure histories from the same 5-shot test acquired with PEW-SOFT at the shooter’s ear are shown below. Again, 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 primary sound signature pressure histories at the ear for all 5 shots are shown in Figure 3. The primary sound signature history is shown on the left. A zoomed-in timescale is displayed on the right, in the region of peak sound pressure. The real sound impulse (momentum transfer potential) histories at the ear from the same 5-shot test are shown in Figure 4. Full and short timescales are shown.
Figure 3a. Savage Arms AccuCan AC22 Subsonic .22 LR Bolt Action Ear Sound Pressure Signature
Figure 3b. Savage Arms AccuCan AC22 Subsonic .22 LR Bolt Action Ear Sound Pressure Signature, Short Time Window
Figure 4a. Savage Arms AccuCan AC22 Subsonic .22 LR Bolt Action Ear Sound Impulse Signature
Figure 4b. Savage Arms AccuCan AC22 Subsonic .22 LR Bolt Action Ear Sound Impulse Signature
The traditional slant baffle monocore design in the AC22 produces exceptional signature suppression on this host weapon. As stated above, the heat transfer advantage of the primarily aluminum construction does contribute to this performance. It is not progressive volumetric expansion, alone, that allows the muzzle signature to exhibit such low amplitude.
With regard to signature characteristics that could be improved on this silencer to reach higher shooter’s ear Suppression Rating potential, the long duration muzzle blast jetting may be somewhat reduced with a more advanced internal design. This nested contribution to the signature measured at the shooter’s ear, with the mechanical operating noise and firing system ignition, can be reduced. Nonetheless, at Suppression Ratings near 90 at the shooter’s ear, operator risk is extremely minimal.
PEW Science Research Note 5: The AC22 exhibits muzzle blast suppression to the shooter, on this platform, that is significant. This level of performance should be expected from high-performance rimfire silencers on this host weapon, in the current state of practice. As stated above, the components of the signature from internal combustion and resonance do influence the severity of the signature at the shooter’s ear. These measurable phenomena are more noticeable than with heavier silencers, for example. The higher early time impulse accumulation in Figure 4b partially illustrates this phenomenon. This accumulation of wave momentum contains components from system firing mechanism and resonance elements that are coupled in the human shooter perception time regime. This total early time signature is unique to all host firearm and silencer combinations; it is an inherent system property. It is not possible to decouple so-called “action noise” of a suppressed weapon system and compare it between suppressed system tests, in way that is meaningful for the end user. The very nature of the silencer’s mechanical properties are coupled in the total system response; changing the silencer changes the “action noise.”
Whereas FRP from the Titanium is postulated to be somewhat imperceptible to bystanders on this host weapon, there is more probability of perceptibility of FRP to the shooter on this system. The FRP to the shooter is still extremely minimal.
PEW Science Research Note 6 (General Rimfire Bolt-Action Rifle System Suppression): If a user desires a Suppression Rating (at the muzzle or shooter’s ear) that is higher than exhibited by the highest performance silencers shown in the Silencer Sound Standard on rimfire bolt-action rifle, it may be prudent for the user to explore different host options, such as rimfire systems with higher mass or impedance mismatches that may contain firing-pin impact noise to a greater degree. Internal material wave propagation may be changed by layering of various materials in a composite structure in a weapon stock, for example. Reduction in signature in such a manner is outside the scope of this article. However, primary mechanical noise limits are the subject of future PEW Science research. Although the PEW Science Suppression Rating Scale is designed for small arms signature damage risk criterion (DRC) applicability, the extreme ends of the scale may be used to quantify such limits, outside the bounds of DRC applicability. It is extremely important to note that mechanical firing system noise (action noise) may change only by changing the mass of an attached silencer, all other things equal, due to dynamic system resonance. This phenomenon is measurable and has been explored in the aforementioned studies.
PEW Science Research Note 7: The signature of a high performance rimfire silencer with subsonic ammunition fired from a bolt-action rifle, at the shooter’s head, is significantly suppressed and may not sound like a “gunshot” to the operator or to bystanders. It is important for operators and bystanders to remain cognizant of the potential hazards of firearm use and the potential lethality of such weapon systems; the operation of such systems, if not in accordance with weapon and silencer manufacturer instructions, may still result in serious injury or death.
6.154.2 Suppression Rating Comparison - Subsonic .22 LR
The Savage Arms AccuCan AC22 was developed to maximize pure sound signature reduction (PEW Science Suppression Rating) in a relatively lightweight envelope. Figure 5 shows a performance comparison of rimfire silencer configurations tested on a bolt-action rifle shown in public PEW Science testing, to date. Suppression Ratings are shown for both the shooter and bystanders.
Figure 5. Suppression Rating Comparisons Of Rimfire Silencers Using PEW-SOFT subsonic .22 LR Bolt-Action Test Data
On longer barrel host weapons, such as the bolt-action rifle used in this test, the Savage Arms AccuCan AC22 produces very high suppression performance. The AC22 is able to outperform some other high-performance silencers such as the Rugged Oculus (6.1), the Mercy Firearms Pluto (6.146), and the Resilient Suppressors Jessie’s Girl (6.125).
At 48% of the weight of the Oculus, 55% of the weight of the Jessie’s Girl, and 80% of the weight of the Otter Creek Labs Titanium (6.149), the Savage AC22 performs very well for its design envelope. It should be noted that both the CAT SR (6.140) and the smaller Mercy Pluto are lighter than the AC22.
Although the AC22 does not exhibit the suppression performance of the lighter CAT SR on this platform, the AC22’s design is not nearly as advanced. For its weight, it is extremely competitive, especially when considering the consistency of its signature suppression on this platform. High pressure rimfire performance is one potentially significant differentiator between the performance of the two silencers.
It should be noted that Suppression Ratings in the 90-zone indicate a significantly suppressed signature. At this level of firearm signature suppression, the Suppression Rating scale quantifies signatures that may not present as similar to gunshots, to most observers. Caution is recommended by both system operators and bystanders (see Research Note 10, below).
It is extremely important to note that mechanical firing system noise (action noise) may change only by changing the mass of an attached silencer, all other things equal, due to dynamic system resonance. This phenomenon is measurable, discussed in Research Note 6, and explored in article 6.141 with CAT SR on the Beretta 21A.
PEW Science Research Note 8: The signature of a high performance rimfire silencer with subsonic ammunition fired from a bolt-action rifle, at the shooter’s head, is significantly suppressed and may not sound like a “gunshot” to the operator or to bystanders. It is important for operators and bystanders to remain cognizant of the potential hazards of firearm use and the potential lethality of such weapon systems; the operation of such systems, if not in accordance with weapon and silencer manufacturer instructions, may still result in unintended serious injury or death. The user is encouraged to be mindful of the degree to which sound signature suppression, and resulting personnel hazards, can vary across designs. 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.
6.154.3 Review Summary: Savage Arms AccuCan AC22 on a CZ 452 .22 Bolt Action with 16-in Barrel
When paired with the CZ 452 American bolt-action rifle and fired with CCI SV .22 LR ammunition, the Savage Arms AccuCan AC22 achieved a composite Suppression Rating™ of 94.5 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 AccuCan AC22 is an extremely lightweight rimfire silencer that exhibits very high suppression performance on rifle systems with notable consistency. The silencer is able to be disassembled for cleaning by hand or with tools, and is constructed of both titanium and aluminum. In addition to its low weight, the AccuCan AC22 allows for extreme suppression potential with subsonic rimfire ammunition on standard barrel length bolt-action rifles.
In the AC22 monocore, washer-type geometry is used, with a flat blast baffle plate and progressively increasing volumetric cavities from proximal to distal end. The progressive volumetric chamber increases along the almost 6-inch length envelope of the AC22, along with the relatively high thermal conductivity of its primarily aluminum construction, enable high suppression efficiency in the tested combustion pressure regime.
On longer barrel host weapons, such as the bolt-action rifle used in this test, the Savage Arms AccuCan AC22 produces very high suppression performance. The AC22 is able to outperform some other high-performance silencers such as the Rugged Oculus, the Mercy Firearms Pluto, and the Resilient Suppressors Jessie’s Girl.
At 60% of the weight of the Oculus, 53% of the weight of the Jessie’s Girl, and 31% of the weight of the Otter Creek Labs Titanium, the Savage AC22 performs very well for its design envelope. It should be noted that it is the same weight as the CAT SR, and heavier than the smaller Mercy Pluto. Although the AC22 does not exhibit the suppression performance of the lighter CAT SR on this platform, the AC22’s design is not nearly as advanced. For its weight, it is extremely competitive, especially when considering the consistency of its signature suppression on this platform. High pressure rimfire performance is one potentially significant differentiator between the performance of the two silencers.
The Savage AC22 exhibits nominal measurable FRP to bystanders on this host weapon platform, but the severity differential between the signatures of FRP and subsequent shots is minimal to non-existent. It is postulated that some bystanders may be able to discern a differential in signature, but the risk profile variation to bystanders is negligible, in accordance with PEW Science analysis.
The Savage Arms AccuCan AC22 silencer may be disassembled by hand or with tools. As the monocore design is aluminum, appropriate cleaners must be used to avoid damage. The user is encouraged to contact the manufacturer for maintenance directives.
PEW Science has not evaluated the durability of the AccuCan AC22, nor its performance on cartridges other than subsonic .22 LR. However, the manufacturer does rate the silencer for use with semiautomatic systems (17 HMR and 22 WMR) as well as fully automatic .22 LR systems with no barrel length restrictions. It is important for the user to contact the manufacturer to determine the suitability of firing schedules and use cases.
In this review, the Savage Arms AccuCan AC22 performance metrics depend upon suppressing a subsonic rimfire cartridge on a bolt-action rifle. While the sound signature of such systems can be suppressed to levels that may not sound like a “gunshot” to the operator or to bystanders, PEW Science encourages the reader to remain vigilant with regard to all subsonic rimfire cartridge suppression claims. It is important for operators and bystanders to remain cognizant of the potential hazards of firearm use and the potential lethality of such weapon systems; the operation of such systems, if not in accordance with weapon and silencer manufacturer instructions, may still result in serious injury or death.
The hazard potential of subsonic rimfire rifle use is not insignificant. PEW Science encourages the reader to consider the Suppression Rating when deciding on an appropriate silencer and host weapon combination for their desired use.
