SSS.6.11 - Dead Air Sandman-S and the Savage Model 10 PC .308
/Dead Air Sandman-S on a Savage Model 10 .308 with 20-in Barrel
The Sandman-S is designed by Dead Air. It is a 30 caliber centerfire rifle silencer, intended to suppress most cartridges with projectiles appropriately sized to travel through the bore, up to and including 300 Winchester Magnum. It has a 1.5-inch diameter and is 6.8 inches in length with the included flat end-cap. Multiple end-cap options are available for use with the Sandman-S. The user may also choose from various Dead Air Keymount muzzle devices on which to mount the silencer to the host weapon with its welded proprietary mount. The outer tube and mount are stainless steel and the cast Stellite baffles of the inner core are fully-welded. The silencer weighs 21.7 ounces with the Keymount flash hider. The Sandman-S can be obtained from Silencer Shop.
This review contains single-test results using the Sandman-S with the Keymount flash hider and flat end-cap on the Savage Model 10 Precision Carbine rifle, chambered in .308WIN with an 20-inch barrel. Federal XM80C 149gr ammunition was used in the test.
Summary: When paired with the Savage M10 20” .308 and fired with Federal XM80C, the Dead Air Sandman-S with the Keymount flash hider achieved a Suppression Rating™ of 32.6 in PEW Science testing.
6.11.1 Dead Air Sandman-S Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Sandman-S 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. Dead air Sandman-S Sound Metric Summary
6.11.1.1 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.
Figure 1 shows a one millisecond long portion of the first round sound pressure signature of the Dead Air Sandman-S as measured 1.0 m left of the muzzle. There are three significant waveform features labeled:
An initial pressure pulse out of the silencer, after the bullet exits the end-cap, causes a 140.6 dB peak.
As gas continues to exit the silencer from the primary combustion event, the measured sound pressure caused by gas jetting increases relatively linearly.
The gas continues to vent to atmosphere with increasing pressure magnitude, eventually reaching a peak sound overpressure of 150.4 dB.
This is the typical sequence observed when firing supersonic .308WIN ammunition from a bolt-action rifle with an attached silencer that exhibits moderate flow restriction (back pressure); however, internal silencer design can significantly influence the measured timing and pressure amplitudes.
Fig 1. Dead Air Sandman-S First Round Bolt Action Rifle Muzzle Sound Pressure Signature, 09-MAY-2020
Closer views of the first peak of all shots (Fig 2a) and highest peak of the first shot (Fig 2b) are shown below. Figure 2a illustrates the consistency of the bullet end-cap exit event between all 5 shots during the test, prior to the influences of internal silencer gas environment. This event is plainly visible and decoupled from the majority of the primary combustion event due to the moderate gas flow restriction exhibited by the Sandman-S silencer. Figure 2b shows points later in time during Shot 1 as the maximum sound pressure occurs from the primary combustion event. Note that the total timescale in Figure 2a is 0.33 milliseconds (330 microseconds) and the total timescale in Figure 2b is only 0.16 milliseconds (160 microseconds). PEW-SOFT provides a sampling point every microsecond and the individual data points are shown in Figure 2b to illustrate this.
Fig 2a. Dead Air Sandman-S Bolt Action Rifle Muzzle Sound Pressure Early-Time Peaks, 09-MAY-2020
Fig 2b.Dead Air Sandman-S Bolt Action Rifle Muzzle Sound Pressure Shot 1 Peak, 09-MAY-2020
The primary sound signature pressure histories for all 5 shots with the Sandman-S are shown in Figure 3a. The sound signatures of Shot 1 and Shot 2 are shown in Figure 3b, in the regions of peak sound pressure. Note the same peak events are labeled for Shot 1 that were previously labeled in Figure 1. The real sound impulse (momentum transfer potential) histories from the same 5-shot test are shown in Figure 4a. In Figure 4b, a shorter timescale is shown comparing the impulse of Shot 1 to that of Shot 2.
Fig 3a. Dead Air Sandman-S Bolt Action Rifle Muzzle Sound Pressure Signature, 09-MAY-2020
Fig 3b. Dead Air Sandman-S Bolt Action Rifle Muzzle Sound Pressure Signature, Short Time Window, 09-MAY-2020
Figure 4a. Dead Air Sandman-S Bolt Action Rifle Muzzle Sound Impulse Signature, 09-MAY-2020
Figure 4b. Dead Air Sandman-S Bolt Action Rifle Muzzle Sound Impulse Signature, Short Time Window, 09-MAY-2020
The measured first-round-pop (FRP) is not immediately evident in the pressure regime. However, when comparing the overall early-time pressure histories of Shot 1 to Shot 2 (Fig 3b), the behavior of gas jetting after a time of 30 ms shows a decreasing rate of pressure rise in Shot 2. This is best illustrated in the impulse regime in Figure 4. Note that after the initial impulse step peak occurs at approximately 30 ms, the slope of the impulse rise of Shot 1 is steeper than that of the subsequent shots. It is important to note that when only viewing the sound pressure regime at the muzzle, Shot 4 possesses the highest peak sound pressure with an amplitude of 153.6 dB. Shot 4 also possesses the highest impulse with an amplitude of 136.1 dB-ms. Nonetheless, the fastest rise-time to peak impulse occurs in Shot 1, as expected.
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. Note the irregularities in first peak time-phasing (Fig 2a) measured at the muzzle with the Sandman-S, when compared to that of the SilencerCo Omega 300 in the previous review (6.10). The baffles of the Sandman-S have a slightly irregular and slotted opening when compared to that of the very similar baffles in the Omega 300. This results in slight gas jetting irregularities which may cause slightly different data acquisition triggering times, from shot to shot. Despite these anomalies, 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 bolt action rifle firearm configuration.
PEW Science note: One notable observation from the measured data is the relatively short rise-time to peak impulse exhibited by the Sandman-S in this test. The rise-time to peak impulse (peak momentum transfer potential) measured 1.0 meter left of the muzzle, of the Sandman-S, after the first shot, when firing supersonic .308WIN ammunition is measured to be faster than that of the Energetic Armament VOX S (Sound Signature Review 6.3), significantly faster than the SilencerCo Omega 300 (Sound Signature Review 6.10), and on par with that of the Q Trash Panda (Sound Signature Review 6.4). This is one objective measurement that indicates the Sandman-S exhibits relatively high gas flow rate and therefore relatively low back pressure characteristics. Although the back pressure generation of the Sandman-S is similar to that of the Q Trash Panda, it is louder than the Trash Panda on the same type of .308 bolt action host weapon and earns a lower Suppression Rating; this is due to internal volume and baffle geometry. Further and more detailed comparisons of the Sandman-S and other 30 caliber centerfire rifle silencers will be presented in future PEW Science Research Supplements.
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.
6.11.1.2 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 5. 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 for Shot 1 and Shot 2. The real sound impulse (momentum transfer potential) histories at the ear from the same 5-shot test are shown in Figure 6. Again, full and short timescales are shown.
Figure 5a. Dead Air Sandman-S Bolt Action Rifle Ear Sound Pressure Signature, 09-MAY-2020
Figure 5b. Dead Air Sandman-S Bolt Action Rifle Ear Sound Pressure Signature, Short Time Window, 09-MAY-2020
Figure 6a. Dead Air Sandman-S Bolt Action Rifle Ear Sound Impulse Signature, 09-MAY-2020
Figure 6b. Dead Air Sandman-S Bolt Action Rifle Ear Sound Impulse Signature, Short Time Window, 09-MAY-2020
Similar to the measurements at the muzzle, there is FRP evident when examining the waveforms measured at the shooter’s ear in early time (Figure 5b), and Shot 4 possesses almost identical peak pressure amplitude to Shot 1 at the ear in late time. Note that, again, the fast rise-time to peak impulse is evident in Shot 1 (Figure 6). Also note the very similar pressure and impulse magnitudes prior to the gas completely exiting the weapon system (between 27 and 29 ms). The supersonic .308WIN platform creates significant sound signature even before the gas completely exits the weapon system, as was shown in the measured muzzle sound pressure and impulse signatures in the previous section.
As typical, the overall sound signature measured at the shooter’s ear possesses significantly less amplitude in both the pressure and impulse regimes than the signature measured at the muzzle (refer to Table 1). Furthermore, the application of both pressure and impulse at the shooter’s ear is delayed when compared to the pressure and impulse at the weapon muzzle. The combination of varying amplitude and rise time to peak amplitude influences the response of the human ear.
Note the higher average pressure and impulse measured at the weapon muzzle and at the shooter’s ear in this test of the Sandman-S when compared to that of the VOX S. Despite these peak amplitude measurements, the Sandman-S exhibits a more favorable human inner ear response than the VOX S on this weapon system and earns a higher Suppression Rating.
6.11.2 Review Summary: Dead Air Sandman-S on a Savage Model 10 .308 with 20-in Barrel
When paired with the Savage M10 20” .308 and fired with Federal XM80C, the Dead Air Sandman-S with the Keymount flash hider achieved a Suppression Rating™ of 32.6 in PEW Science testing.
PEW Science Subjective Opinion:
The Dead Air Sandman-S is a compact 30 caliber machine gun rated rifle silencer that possesses moderate sound signature suppression performance with lower back pressure. The silencer is advertised to have extreme durability and is one of the heavier silencers on the market for its size, at a total system weight of 21.7 ounces, as tested.
The Sandman-S uses an iteration of a feature-reduced and modified stepped-cone baffle, similar to the feature-reduced curved-cone baffle used in the Omega 300 from SilencerCo and other companies, with the primary difference being an enlarged center orifice to facilitate higher axial gas flow rate. The influence of the larger center orifice on rise-time to peak impulse is as expected. This flow rate enhancement, evident from the impulse histories measured in the test, results in moderate sound suppression with lower “back pressure.” The back pressure generation of the Sandman-S is on par with that of the Q Trash Panda, for example. However, the Sandman-S is louder than the Trash Panda on the same type of .308 bolt action host weapon and earns a lower Suppression Rating; this is due to internal volume and baffle geometry.
The ratcheting proprietary mount welded to the rear of the Sandman-S that interfaces with Dead Air Keymount muzzle devices is relatively simple to operate. The mount can facilitate the installation of the silencer underneath a handguard or on barrels that have exterior obstructions which may prevent the fastening of traditional locking collars. This capability is achieved by rotating the entire silencer body during installation, rather than actuating a localized mount ring or lever. However, it is important to note that radiant heat during use of a silencer placed under the handguard of a semiautomatic rifle can be significant. PEW Science urges users to consider radiant heat when deciding on specific silencer mounting configurations.
The Sandman-S is marketed to be durable and is advertised to not have any restrictions on barrel length; therefore it may be used with aggressive semiautomatic and automatic firing schedules. Despite this allowance, the designers of the silencer rate the system for pressures generated by cartridges up to 300 Winchester Magnum and not a higher pressure rating (300 Remington Ultra Magnum, for example). It is postulated that the reduction in rating is due to the Keymount system limitations. Therefore, PEW Science encourages the user to contact the silencer designer prior to use with high power magnum rifle cartridges. This caution may not be intuitive to some users due to the Sandman-S being marketed as a machine gun silencer.
The combination of durability and lower back pressure makes the Sandman-S a reasonable choice for semiautomatic and automatic centerfire rifle use, particularly for cases in which back pressure is a concern. PEW Science has not yet evaluated the Sandman-S on semiautomatic or automatic small arm weapon systems.
In this review, the Sandman-S 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.
