SSS.6.36 - Griffin Armament Explorr EX3 and the Savage Model 10 PC .308 (Free Version)
/Griffin Armament Explorr EX3 on a Savage Model 10 .308 with 20-in Barrel
The Explorr .300 (also known as the Explorr EX3) is designed and manufactured by Griffin Armament. It is a 30 caliber centerfire rifle silencer, intended to suppress most cartridges with projectiles appropriately sized to travel through the bore, including 300 Winchester Magnum. It has a 1.5-inch diameter and is 6.4 inches in length. The silencer mounts to proprietary Griffin Armament taper-mount muzzle devices. The silencer is tubeless and constructed of H900 heat-treated 17-4 stainless steel. The silencer weighs 15.3 ounces with the two-port taper mount Paladin brake, as tested. The Explorr EX3 can be obtained from Silencer Shop.
This review contains single-test results using the Explorr EX3 mounted with the two-port taper mount brake on the Savage Model 10 Precision Carbine rifle, chambered in .308WIN with a 20-inch barrel. Federal XM80C 149gr ammunition was used in the test.
Section 6.36.1 contains the results of the Explorr EX3 Test.
Section 6.36.2 contains back pressure and Suppression Rating comparisons with selected compact to mid-size .30 rifle silencers. Rev.2 of the PEW Science Back Pressure Metric is presented.
Section 6.36.3 contains detailed sound signature comparisons of the Explorr EX3 with the Dead Air Sandman-K, the CGS Hyperion K, and the YHM Resonator K in the supersonic flow regime, with back pressure research notes and a Rugged Rifle Silencer Back Pressure Case Study.
Section 6.36.4 contains the review summary and subjective PEW Science opinions.
Summary: When paired with the Savage M10 20” .308 and fired with Federal XM80C, the Griffin Armament Explorr EX3 mounted with the two-port taper mount brake achieved a Suppression Rating™ of 27.5 in PEW Science testing.
Relative Suppression Rating Performance is Summarized in SSS.7 - PEW Science Rankings
6.36.1 Griffin Armament Explorr EX3 Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Explorr EX3 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. Griffin Armament Explorr EX3 Sound Metric Summary
6.36.1.1 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 1 millisecond long portion of the first round sound pressure signature of the Explorr EX3 as measured 1.0 m left of the muzzle. There are three significant waveform features labeled:
The endcap exit event results in an initial overpressure peak magnitude of 143.1 dB.
A major jet peak occurs with an amplitude of 148.7 dB.
Peak FRP is reached at a maximum of 150.3 dB.
This is a somewhat 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 6.36.2 of this review, with the updated PEW Science Rev.2 Back Pressure Metric.
Fig 1. Griffin Armament Explorr EX3 First Round Bolt Action Rifle Muzzle Sound Pressure Signature, 24-OCT-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. Note the consistency in both amplitude and wave shape which are captured accurately due to the sample rate and raw, unfiltered data stream from PEW-SOFT. 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 0.28 milliseconds (280 microseconds) and the total timescale in Figure 2b is only 0.1 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. Griffin Armament Explorr EX3 Bolt Action Rifle Muzzle Sound Pressure Early-Time Peaks, 24-OCT-2020
Fig 2b.Griffin Armament Explorr EX3 Bolt Action Rifle Muzzle Sound Pressure Shot 1 Peak, 24-OCT-2020
The primary sound signature pressure histories for all 5 shots with the Explorr EX3 are shown in Figure 3a. The sound signatures of Shot 1 and Shot 2 are shown in Figure 3b, in early time. 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. Griffin Armament Explorr EX3 Bolt Action Rifle Muzzle Sound Pressure Signature, 24-OCT-2020
Fig 3b. Griffin Armament Explorr EX3 Bolt Action Rifle Muzzle Sound Pressure Signature, Short Time Window, 24-OCT-2020
Figure 4a. Griffin Armament Explorr EX3 Bolt Action Rifle Muzzle Sound Impulse Signature, 24-OCT-2020
Figure 4b. Griffin Armament Explorr EX3 Bolt Action Rifle Muzzle Sound Impulse Signature, Short Time Window, 24-OCT-2020
The Explorr EX3 does not exhibit significantly perceptible first round pop (FRP) at the muzzle on this platform; this is most likely due to its high flow rate, which is discussed below. Nonetheless, the FRP phenomenon is observable in the pressure regime, and it is further evident upon examination of the impulse waveforms in Figure 4 in both impulse rise time and slope. PEW Science inner ear modeling indicates FRP will be more perceptible to the shooter than to bystanders with the Explorr EX3 on this host weapon platform.
PEW Science Note: The Explorr EX3 exhibits a relatively fast rise to peak positive phase impulse amplitude. When first examining the early-time pressure amplitudes, it is not immediately apparent that the positive phase impulse reaches a maximum so quickly. Comparisons with other low backpressure compact silencers are shown in Section 6.36.3 of this review. Other than different baffle geometries and spacing, this flow rate increase is most likely due to the notched porting close to the center axial orifice of each baffle in the Explorr EX3. This increased flow area close to the bore is significant, and present through the entire baffle stack. Even with the presence of 6 baffles, the silencer is able to reach peak positive phase impulse at a faster rate than the CGS Hyperion K (Review 6.28), for example. This phenomenon is postulated to indicate significantly increased flow rate when compared to other 30 caliber silencers on the market. Rise time rate is a new parameter included in PEW Science back pressure research (see Sections 6.36.2 and 6.36.3 of this review).
The overall, muzzle, and ear Suppression Ratings for silencers tested by PEW Science, to date, can be compared directly using the tool in Section 7 of the Silencer Sound Standard - PEW Science Rankings. The Explorr EX3 is quieter than the YHM Resonator K (Review 6.32) at the muzzle, for example, but louder than the Resonator K at the shooter’s ear on this platform. The Explorr EX3 is quieter than the Dead Air Sandman-K (Review 6.15) on this platform at both the muzzle and at the shooter’s ear.
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 will be published in the future.
6.36.2 Relative Back Pressure and Suppression Rating Comparison (.30 Rifle Silencers)
The Explorr EX3 suppressor is intended to be light weight and used for hunting, precision rifle shooting, and short barrel rifle use, with balanced sound suppression and back pressure performance. PEW Science is currently conducting silencer back pressure research. Figure 7 shows preliminary relative 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 7 are calculated from real test data acquired with PEW-SOFT. Please note the following:
Back Pressure Research is ongoing. The rate at which peak gas momentum transfer potential is achieved, as measured 1.0 m left of the weapon muzzle, is the objective quantity used to generate the back pressure data summary in this review (this is the principal change in Rev.2 of the metric). This differs from previous reviews, in which only rise-time to peak impulse was used. Slope (rate) is now incorporated into the metric. The metrics shown are normalized and relative to unsuppressed gas flow. The metrics are now proportional to the rate of impulse rise [Pa-ms / ms] and the metric scaling relationships between silencers is nonlinear. Future iterations of the metric may be updated due to future scaling relationship research and development.
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.
Back Pressure Data is normalized to the silencer with the highest back pressure shown, which is the CGS Helios QD with solid endcap from Sound Signature Review 6.13.
It is important to note that the plotted Back Pressure Metric is a preliminary research quantity. It is an empirically derived quantity that shows strong correlation to actual silencer back pressure generation on semi-automatic weapon platforms. Host sensitivity to backpressure, field study, and further research, is described below and in Section 6.36.3 of this review.
Figure 7. Back Pressure And Suppression Rating Comparisons Of .308 Rifle Silencers Using PEW-SOFT Data
The data in the above table is sorted by Rev.2 of the back pressure metric. From the data, it can be concluded that the Griffin Armament Explorr EX3 suppressor may produce lower back pressure than the CGS Hyperion K and slightly higher back pressure than the vented CGS Helios QD. As previously stated in Section 6.36.1.1, the reasons for this postulated low back pressure are due to baffle porting throughout the entire baffle stack that creates significant flow area in close proximity to the bore.
The Explorr EX3 was tested with the Griffin two-port taper mount muzzle brake. It is possible that the flow behavior of the silencer may change when a different mount system and muzzle device is used. Anecdotal user reports indicate variable flow (back pressure) observations with some silencers using different mount systems. PEW Science has not examined the influence of mount system on silencer back pressure.
It is important to note that the back pressure potential of silencers, in general, may not be significant in all practical use. Also, users may sometimes confuse mount leakage for flow restriction related to back pressure. For an example of severe performance differential when mount sealing is compromised due to mount design, unrelated to back pressure, see the PEW Science data with the Surefire WARCOMP mount and SOCOM762-RC2 in Sound Signature Review 6.26.
It is important to note that back pressure is not the same phenomenon as blow back. Back pressure may cause blow back on a host weapon, or it may not influence host weapon operation when compared to the unsuppressed state; the influence of back pressure characteristics on a silencer’s performance on semi-automatic and automatic hosts may depend on the respective metric magnitudes; this is the subject of future PEW Science research. For example, it is postulated that there is a threshold back pressure metric below which adequate semi-automatic weapon function on typical 5.56x45mm host weapons may be achieved. Whether that threshold is 0.57 in Figure 7 (the Rugged Razor) or 0.60 (the Surefire SOCOM762-RC2), for example, will depend on the particular host weapon configuration. Recent PEW Science research at the time of this review publication indicates that a back pressure metric threshold is probable for gas operated 5.56x45mm small arms. Current research indicates that host weapon component dynamics (AR15 platform bolt carrier, buffer mass, and gas port size) can significantly influence suppressed weapon system performance. Further research is ongoing.
For example, an 11.5-inch AR15 chambered in 5.56x45mm with a mid-length gas system and adequate reciprocating mass (an H3 buffer weight, for example) may be able to be suppressed with any silencer shown in Figure 7 without undue gas blow back noted by the shooter. This type of suppressed small arm weapon system is an example of a gas insensitive host. Conversely, a 14.5-inch AR15 in the same chambering with a carbine-length gas system, relatively large gas port, and standard weight carbine buffer, may produce severe gas blow back noted by the shooter, even with a silencer such as the Surefire SOCOM762 RC2, which is shown in Figure 7 to have a normalized back pressure metric much lower than even some mid-size silencers. This type of suppressed small arm weapon system is an example of a gas sensitive host. On the AR15 platform, silencer gas flow (back pressure) sensitivity is a function of dwell time, inertial resistance, and lock time. Other host weapon types have characteristics that result in more or less gas sensitivity in suppressed operation.
PEW Science Field Note: A real field-example demonstrating the gas sensitivity of hosts is highlighted by current PEW Science research with the CGS Helios QD and Helios QD Ti. Those two silencers, when used with the aforementioned 11.5-inch mid-length gas Surefire OBC (carrier+H3 equivalent mass) equipped AR15 do not induce “blow back” to the shooter, even with sustained fully-automatic fire. This behavior is observed despite the Helios QD system exhibiting the highest back pressure metric in Figure 7. The host weapon is tuned to be gas insensitive.
PEW Science Research Note: The relative back pressure percentages described in this section are only valid when examining the data normalized to the CGS Helios QD with solid endcap in Figure 7. PEW Science back pressure research is ongoing. Membership contributions to PEW Science help fund such research.
The Griffin Armament Explorr EX3 is slightly quieter than the CGS Hyperion K and Rugged Radiant to observers. However, it is louder than both of those silencers at the shooter’s ear on this platform. The Explorr EX3 is quieter than the Sandman-K to both observers and the shooter, and is postulated to generate somewhat higher backpressure. Detailed comparisons follow.
6.36.3 Detailed Supersonic Waveform Comparisons and Backpressure Research
The Explorr EX3 exhibits a relatively fast rise to peak positive phase impulse that is the subject of further PEW Science research. This Sound Signature Review subsection is intended to provide context for back pressure research to readers by comparing the waveforms of other silencers that exhibit similar phenomena. The following discussion delineates between rise-time to peak impulse and the rate of that rise, which is not necessarily the same.
Figure 8a shows four waveforms in impulse space; each of Shot 2 from a 5-shot test of each silencer. Shot 2 is presented, rather than Shot 1, to compare impulse rise-time of the silencers without the influence of ancillary FRP combustion. The maximum amplitude of each curve is labeled:
The Griffin Armament Explorr EX3; it has the fastest rise to peak positive phase impulse of the group (but not the fastest impulse rise rate).
The Dead Air Sandman-K; this silencer is the second fastest to reach peak, but has the fastest impulse rise rate.
The CGS Hyperion K; this silencer has a very similar peak impulse amplitude to the Explorr EX3, but it occurs later in time, and at a slower rate.
The YHM Resonator K; this silencer takes the longest to rise to peak positive phase impulse of the group, and it has the slowest impulse rise rate.
Figure 8a. Bolt Action Rifle Supersonic .308 Muzzle Sound Impulse Signature Comparison (Shot 2)
The PEW Science Back Pressure Hypothesis used to formulate the Rev.1 backpressure metric shown in the previous reviews only considered rise-time. In that revision of the metric, the postulation was that after peak positive phase impulse measured 1.0 m left of the silencer end-cap occurs, rarefaction begins to overwhelm positive phase impulse accumulation, indicating that flow rate through the silencer has passed its maximum.
Theoretically, as impulse is a measure of the momentum transfer potential exhibited by a flow, the sound signatures in the impulse regime are postulated to present clear delineation of the maximum particle velocity events in the time domain. However, the rate at which the maximum impulse is reached is further postulated to correlate directly to flow rate through the silencer, and that rate is a function of not only the absolute time of peak impulse, but the impulse amplitude at that time.
Rev.2 of the Back Pressure Hypothesis, and the accompanying Rev.2 metric has recently been developed by PEW Science. To illustrate the changes to the results using the new metric, normalized metric quantities, using both Rev.1 and Rev.2 metrics, are presented for the five silencers of interest in Figure 8b, below.
Figure 8b. Back Pressure Metric Comparisons Of .308 Rifle Silencers Using PEW-SOFT Data
Note that the general trend of the Rev.1 metric is somewhat followed, but there are some key changes with the Rev.2 metric. With the revised back pressure metric, the Explorr EX3 is shown to have postulated back pressure (flow restriction) in-between that of the Hyperion K and the Sandman-K. Using Rev.1 of the metric, the Explorr EX3 would be predicted to have lower back pressure than the Sandman-K; this is a consequence of significantly different peak impulse amplitudes reached with the two silencers. Research and analysis is ongoing, with supplementary studies being conducted on various weapon platforms. An example of supplementary study follows.
6.36.3.1 Rugged Rifle Silencer Backpressure Research Case Study
Figure 9a shows measured PEW-SOFT muzzle impulse waveforms for five silencers manufactured by Rugged Suppressors. Each silencer has a different number of baffles, different baffle spacing, and different overall length. PEW Science has tested these silencers on semi-automatic host weapon platforms chambered in 5.56x45mm and 7.62x51mm. The observations from those live fire tests are:
The Rugged Surge in its long configuration exhibits the highest back pressure of the group. Adjustable gas blocks on the tested 5.56mm and 7.62mm weapon systems must be adjusted to restrict gas flow further than with the other silencers in the group to achieve favorable weapon function.
The Surge in its short configuration exhibits less back pressure than it does in its long configuration.
The Rugged Radiant in its long configuration is approximately the same size as the short configuration of the Surge. However, the baffle configuration is different, and lower back pressure is observed with the long configuration of the Rugged Radiant than with the short configuration of the Surge. Over-function is less prevalent with the Radiant than it is with the Surge.
The Rugged Razor exhibits lower back pressure than the long configuration of the Rugged Radiant. Weapon over-function is minimal.
The short configuration of the Rugged Radiant exhibits the lowest backpressure of the group, and adjustment of gas operated weapon systems to achieve function with this silencer configuration is not typically required.
When examining the relative rise-times of the waveforms shown in Figure 9a in context with the five observations noted above, correlation between rise time to peak impulse and generated back pressure is noted.
The Rugged Radiant in its short configuration reaches maximum peak positive phase impulse first.
The Rugged Razor is the second silencer to reach maximum impulse.
The long configuration of the Radiant follows.
The short configuration of the Surge is somewhat slower than the Radiant.
The long configuration of the Rugged Surge takes the longest time to reach positive phase impulse.
This sample field case study demonstrates correlation between the previous Rev.1 PEW Science back pressure metric and observed back pressure on semi-automatic host weapons.
Figure 9a. Bolt Action Rifle Supersonic .308 Muzzle Sound Impulse Signature Comparison of Rugged Rifle Silencers (Surge, Radiant, and Razor; final 4 shots of each 5 shot test)
The updated Rev.2 metric indicates some changes in the above back pressure relationships, but the relative flow restriction relationship trends are largely unchanged. A comparison of the computed Rev.1 and Rev.2 back pressure metrics for the five aforementioned Rugged rifle silencers is shown in Figure 9b, below.
Figure 9b. Back Pressure Metric Comparisons Of .308 Rifle Rugged Rifle Silencers Using PEW-SOFT Data
As indicated, the Rev.2 back pressure metric also shows general correlation with field results. Research is ongoing. Third-party anecdotal, experimental, and analytical data regarding back pressure metric research may be submitted to PEW Science through this website, here. PEW Science thanks you for your interest in our continued research of suppressed small arms.
6.36.4 Review Summary: Griffin Armament Explorr EX3 on a Savage Model 10 .308 with 20-in Barrel
When paired with the Savage M10 20” .308 and fired with Federal XM80C, the Griffin Armament Explorr EX3 mounted with the two port tapered muzzle brake achieved a Suppression Rating™ of 27.5 in PEW Science testing.
PEW Science Subjective Opinion:
The Griffin Armament Explorr EX3 is a compact and relatively lightweight and durable .30 rifle silencer. The Explorr EX3 is versatile in that it may be used on many cartridges with a variety of Griffin Armament taper mount adapters. The user should note that it is a compact silencer and therefore its sound signature suppression performance is lower than that of larger silencers.
The Explorr EX3 contains six baffles. The baffles are stepped and notched cones with porting cuts close to the bore in each baffle in the tubeless stack. As stated in this Sound Signature Review, it is postulated that the repeated porting in close proximity to the bore results in relatively high flow rate. The back pressure metric data presented may be an indicator of this. A notable phenomenon observed in the performance of the Explorr EX3 is that it is postulated to exhibit higher flow rate than the YHM Resonator K, but be significantly quieter than that silencer at the muzzle on this host weapon platform. While it did not reach the at-ear Suppression Rating of the Resonator K in PEW Science testing, the overall loudness of that system is comparable. First round pop (FRP) performance of the Explorr EX3 in the supersonic flow regime was measured to be respectable at the muzzle; this is most likely related to its postulated higher flow rate, as silencers that exhibit high flow rate possess sound signatures that are not easily overwhelmed by ancillary first round combustion.
The Griffin Armament taper mounts are relatively simple to operate. The mount system has threading forward of the seating and sealing taper, which some users report to influence thread fouling with debris due to thread tolerance allowing debris propagation. Nonetheless, routine cleaning of the mount is relatively simple and is not anticipated to present users with issues if maintenance is performed. It should be noted that PEW Science does have experience with the Griffin Armament taper mount system loosening during heating and cooling cycles. However, that phenomenon did not occur during this test of the Explorr EX3. Care must be taken to secure non-latching taper mounts, as there may be no visual indicator that the mount is attached. This is also the case with other taper mounts on the market from other manufacturers.
PEW Science tested this silencer with a compact two-port taper mount brake, and not the Griffin Armament “Tactical Compensator.” Users have provided anecdotal reports indicating that different mounting solutions may result in different back pressure characteristics with certain silencers. This phenomenon has not been investigated by PEW Science.
In this review, the Explorr EX3 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.
