SSS.6.15 - Dead Air Sandman-K and the Savage Model 10 PC .308 (Free Version)
/Dead Air Sandman-K on a Savage Model 10 .308 with 20-in Barrel
The Sandman-K 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 5.4 inches in length with the included flat end-cap. Multiple end-cap options are available for use with the Sandman-K. 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 16.8 ounces with the Keymount flash hider. The Sandman-K can be obtained from Silencer Shop.
This review contains single-test results using the Sandman-K 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-K with the Keymount flash hider achieved a Suppression Rating™ of 24.2 in PEW Science testing.
6.15.1 Dead Air Sandman-K Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Sandman-K 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 PEW Science testing, research, and development with a membership, here. State-of-the-art firearm sound signature testing and research conducted by PEW Science is supported by readers like you.
Table 1. Dead air Sandman-K Sound Metric Summary
6.15.1.1 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-K as measured 1.0 m left of the muzzle. There are four significant waveform features labeled:
An initial pressure pulse out of the silencer, after the bullet exits the end-cap, causes a 144.6 dB peak.
Very soon after the end-cap exit event, jetting initiates with a 158.2 dB peak.
The measured sound pressure increases to a maximum of 159.2 dB
As gas continues to exit the silencer from the primary combustion event, secondary jetting results in a peak 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 low flow restriction (back pressure); however, internal silencer design can significantly influence the measured timing and pressure amplitudes. Preliminary back pressure comparisons are shown in Section 6.15.2 of this review.
Fig 1. Dead Air Sandman-K 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 low gas flow restriction exhibited by the Sandman-K suppressor. 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 0.50 milliseconds (500 microseconds) and the total timescale in Figure 2b is only 0.10 milliseconds (100 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-K Bolt Action Rifle Muzzle Sound Pressure Early-Time Peaks, 09-MAY-2020
Fig 2b. Dead Air Sandman-K 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-K 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 and Shot 3.
Fig 3a. Dead Air Sandman-K Bolt Action Rifle Muzzle Sound Pressure Signature, 09-MAY-2020
Fig 3b. Dead Air Sandman-K Bolt Action Rifle Muzzle Sound Pressure Signature, Short Time Window, 09-MAY-2020
Figure 4a. Dead Air Sandman-K Bolt Action Rifle Muzzle Sound Impulse Signature, 09-MAY-2020
Figure 4b. Dead Air Sandman-K Bolt Action Rifle Muzzle Sound Impulse Signature, Short Time Window, 09-MAY-2020
The measured first-round-pop (FRP) is evident in both the pressure and impulse regimes. When comparing the overall early-time pressure histories of Shot 1 to Shot 2 (Fig 3b), the gas jetting in Shot 1 has a higher duration than the jetting 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 29.6 ms, the slope of the impulse rise of Shot 1 is steeper than that of the subsequent shots. It is important to note that the impulse of Shot 3 and Shot 4 drop significantly, and the impulse of Shot 5 rises again, but never reaches the magnitude of Shot 1 or Shot 2. 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 that the time phasing of Shot 2 in Figure 4b was shifted in time, globally, to illustrate key waveform features between the FRP event and the subsequent shot. As stated in the figure notes, gas jetting anomalies caused by significant early-time flow result in slight PEW-SOFT data acquisition triggering time differences from shot to shot. These irregularities in first peak time-phasing (Fig 2a) measured at the muzzle with the Sandman-K are similar to those observed in testing of the Dead Air Sandman-S in Sound Signature Review 6.11. Like the Sandman-S, the baffles of the Sandman-K have a slightly irregular and slotted opening when compared to that of the very similar baffles in the SilencerCo Omega 300 (Sound Signature Review 6.10) or the Rugged Radiant (Sound Signature Review 6.12). 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 impulse waveform shapes 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-K in this test. The rise-time to peak impulse (peak momentum transfer potential) measured 1.0 meter left of the muzzle, of the Sandman-K, after the first shot, when firing supersonic .308WIN ammunition is measured to be faster than that of the Rugged Radiant in its short configuration, and faster than the CGS Helios QD with its vented end-cap (Sound Signature Review 6.13). This is one objective measurement that indicates the Sandman-K exhibits high gas flow rate and therefore potentially low back pressure characteristics. Although the back pressure generation of the Sandman-K is potentially lower than the short configuration of the Radiant and vented configuration of the Helios QD, it is quieter than both of those silencers on the same host weapon and earns a higher Suppression Rating. More detailed and direct comparisons are provided in Section 6.15.2 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.
6.15.2 Relative Back Pressure and Suppression Rating Comparison (.30 Rifle Silencers)
PEW Science Research Note: As of February 2021, back pressure characterization has undergone refinement and Rev.2 of the Back Pressure Metric has been developed. Research is ongoing. Please see back pressure research updates starting with Sound Signature Review 6.36.
The Sandman-K suppressor is intended to be compact and reduce back pressure. PEW Science is currently conducting silencer back pressure research. Figure 7 shows preliminary relative back pressure comparisons between selected “low back pressure” 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 7 are calculated from real test data acquired with PEW-SOFT. Please note the following:
The time to reach peak gas momentum transfer potential, as measured 1.0 m left of the weapon muzzle, is the objective quantity used to generate the back pressure data summary.
The waveform characteristics of unsuppressed shots with the same ammunition used in the respective tests are used in the calculations and the unsuppressed relative back pressure and Suppression Rating quantities are shown.
The first shot from each silencer test is omitted from the back pressure computations due to internal gas environment characteristics within the silencer (FRP) that influence peak impulse amplitude, wave-shape, and timing. All unsuppressed shots are included.
Data is normalized to the silencer with the highest back pressure and Suppression Rating shown, which is the Q Trash Panda from Sound Signature Review 6.4.
Figure 7. Back Pressure And Suppression Rating Comparisons Of .308 Rifle Silencers Using PEW-SOFT Data
From the above data, it can be concluded that the Sandman-K suppressor is capable of significantly reduced back pressure. It is postulated that the back pressure of the Sandman-K is approximately 69% lower than that of the Trash Panda. Of particular note is that the Sandman-K is postulated to have 4% lower back pressure than the Rugged Radiant in its short configuration and 8% lower back pressure than the Helios QD in its vented configuration. This is noteworthy, as the Sandman-K has a higher Suppression Rating than both of those silencers. It is also important to note that the back pressure potential of these three silencers is relatively low and the back pressure differences may not be significant in practical use with semi-automatic and automatic hosts; this is the subject of future PEW Science research.
PEW Science note: The relative percentages described in this section are only valid when examining the data normalized to the Trash Panda in Figure 7. PEW Science back pressure research is ongoing. Membership contributions to PEW Science help fund such research.
The Dead Air Sandman-K is significantly louder than mid-size 30 caliber rifle silencers, like the Trash Panda and Sandman-S, but is predicted to exhibit significantly lower back pressure.
6.15.3 Review Summary: Dead Air Sandman-K 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-K with the Keymount flash hider achieved a Suppression Rating™ of 24.2 in PEW Science testing.
PEW Science Subjective Opinion:
The Dead Air Sandman-K is a subcompact 30 caliber machine gun rated rifle silencer that possesses low sound signature suppression performance with very low 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 16.8 ounces, as tested.
Like the other Sandman series 30 caliber suppressors from Dead Air, the Sandman-K 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, its small size, and its reduced number of baffles, results in low sound suppression with very low “back pressure.” The back pressure generation of the Sandman-K is lower than that of the Rugged Radiant in its short configuration and the CGS Helios QD in its vented configuration. However, the Sandman-K is quieter than both of those silencer configurations on the same host weapon and earns a higher Suppression Rating.
The ratcheting proprietary mount welded to the rear of the Sandman-K 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 the 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-K 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-K being marketed as a machine gun silencer.
The combination of durability, small size, and low back pressure makes the Sandman-K a reasonable choice for semiautomatic and automatic centerfire rifle use, particularly for cases in which both size and back pressure are a concern. PEW Science has not yet evaluated the Sandman-K on semiautomatic or automatic small arm weapon systems.
Users may compare the Sandman-K to the short configuration of the Rugged Radiant due to the similar sizes of the two silencers. It is expected that the significant weight difference will be considered in such a comparison, along with the desired host weapon use. For bolt action applications in which firing schedules may be minimal, the higher Suppression Rating of the Sandman-K may not be as important to some users looking for a lightweight hunting silencer that is compact; the short configuration of the Radiant is only 5.1 inches long. For semi-automatic use cases in which the shooter may be using hearing protection, the Radiant may also be an attractive alternative due to smaller size and lighter weight, at the expense of slightly higher back pressure potential. However, for abnormally severe firing schedules, the Sandman-K may be compared to the CGS Helios QD in its vented configuration. It is also important to note that the back pressure potential of these three silencers is relatively low and the differences may not be significant in practical use with semi-automatic and automatic hosts; this is the subject of future PEW Science research.
In this review, the Sandman-K 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.
