SSS.6.174 - B&T Station SIX 9 with B&T SIX 9 Wiped and Training Silencers (Free Version)
/B&T Station SIX 9 Wiped and Training Silencers on the B&T Station Station SIX 9 Bolt-Action Pistol
The SIX family of weapons is designed and manufactured by B&T AG of Switzerland, and includes several variants. For the U.S. market, two systems are marketed and available; the B&T Station SIX 9 and Station SIX 45. Due to U.S. silencer import restrictions, the accompanying SIX 9 and SIX 45 silencers are manufactured in the United States by B&T USA, Florida. This article contains technical information and performance data and analysis for the U.S. SIX 9 system, its included silencer, and its separately available Training silencer. It is important to note that the U.S. SIX 9 system is not integrally suppressed (there is no ported barrel), its grip housing does not detach from the main frame (although their is scoring to facilitate user-modification), and no tools are included with the U.S. retail package for weapon or silencer maintenance. This differs from the “Veterinary Pistol SIX,” “VP9,” and other B&T AG designations that appear in marketing literature. The B&T Station SIX 9 and the B&T VP9 systems are not the same. The Station SIX 9 can be obtained from Silencer Shop. The SIX 9 Training silencer can be obtained from Capitol Armory.
B&T Station SIX 9 Weapon System Physical Details
As stated, this analytical test report addresses the performance of two SIX 9 silencers fielded on the B&T Station SIX 9 bolt-action pistol. The pistol fires from a locked breach; the bolt assembly mechanism is manually rotated. To actuate it, the operator must fully depress the rear grip safety located in the grip tang closest to the bore axis. The operator must then rotate the knurled bolt handle counter clock-wise and retract the bolt rearward. This action will eject a cartridge (if unfired) or spent casing (if fired). To chamber another cartridge, the process is reversed; the bolt is pushed forward and then rotated clock-wise to lock. The action is magazine-fed and the included magazine is a single-stack 9-round model manufactured by Mec-Gar, Italy. The magazines may be considered standard 9mm 1911-pattern compatible. An extra round may be chambered in the pistol with the magazine fully loaded with 9 rounds, for a final loading of 10 total cartridges.
The 3.5-in barrel of the U.S. B&T Station SIX 9 is threaded in the conventional 1/2”-28tpi diameter and pitch and may accept direct-thread 9mm pistol silencers from other brands. The fixed barrel contains adequate shoulder area for gas sealing of most conventional fixed silencer mounts; most conventional 1/2”-28tpi devices index on the shoulder. Unloaded, with an empty magazine inserted, and no silencer attached, the SIX 9 pistol weighs 31.9 ounces, as tested.
B&T Station SIX 9 Silencer Physical Details
Both the included SIX 9 silencer and the Training silencer contain exterior o-rings on a reduced proximal diameter. These o-rings serve two functions; the first is to interface with the outer pistol frame shroud and prevent unintended silencer loosening. The second function is to provide another gas seal; the blast load generation of a closed-bolt system is of a higher internal duration than in typical semiautomatic pistols due to less vent area. Therefore, pressure leaks from unsealed threaded junctions are more likely to occur. This has been observed in internal PEW Science laboratory testing.
The included B&T SIX 9 silencer has no conventional baffles and contains four rubber wipes in its aluminum body, each separated by two spacers. The assembly is captured by the aluminum end cap. The rubber used for the wipes has a reported third-party durometer-measured Shore hardness of 80A. Each wipe is approximately 1/4-in thick and pre-scored in a cross pattern; the scoring centered axially. The wipes are consumable parts and become damaged with each shot fired through the system. From end cap to the step-down mating shoulder forward of the proximal o-ring, the SIX 9 silencer is 5.4 inches long. It has a 1.38-in diameter and weighs 5.9 ounces, post-test. It is possible that some weight reduction occurred from wipe damage during testing, though it is estimated that would be limited to a magnitude of approximately 0.1 ounces or less. The silencer may be disassembled for wipe replacement and maintenance with a tool available from B&T AG, and potentially from B&T USA.
B&T Station SIX 9 Training Silencer Physical Details
The separately available and tested B&T SIX 9 Training silencer is identical in exterior physical dimensions to the included wiped SIX 9 silencer. The Training silencer weighs 5.8 ounces as tested and contains five aluminum baffles. The baffle geometry used is a traditional star-shaped machined derivative, similar to the original crimped-cone baffle geometry first developed by Douglas Olson at Qual-A-Tec and Automatic Weapons Company (AWC), later popularly adopted by Knights Armament Company (KAC) for use in many of their silencers during his employment there. The silencer does possess machined holes on its end cap that imply disassembly is possible, though the capability for user-disassembly is unknown. It is possible thread-locking compound is used in assembly. User caution is advised.
B&T Station SIX 9 Test Protocol
All testing and analysis reported on this website is performed in accordance with the Silencer Sound Standard. Bolt-action systems are tested with 5 rounds, whereas semiautomatic systems are tested with 6 rounds. In all cases, Suppression Rating metrics are calculated using 5 shots, and only 5 shots, regardless of weapon system. This practice is kept constant such that all system results may be compared to each other and first-round-pop (FRP) phenomena is always equally weighted in the analytical engineering calculations. In almost all conventional systems, silencer performance past the fifth shot differs nominally. In some cases, performance may drop due to system heating. Again, this holds true for most conventional systems.
As discussed, the B&T Station SIX 9 was tested with two SIX 9 silencers. In the case of the Training silencer, the standard bolt-action test protocol was followed; 5 cartridges were loaded into the magazine, a new cartridge was chambered after each shot was fired, and this process continued until the weapon was empty. Bolt actuation and cartridge chambering by the test operator was performed as expediently as possible, while still adhering to safe firearm handling practice and standard PEW Science laboratory safety and operational procedures. The propensity for misfeed is high with the B&T Station SIX 9 system, and care was taken to prevent these malfunctions as to not delay test shots. It is important to note that the ejection port may be cupped by the support hand to assist with certain portions of the operation; the support hand thumb actuating the grip safety to allow bolt operation.
In the case of the included wiped SIX 9 silencer, full system capacity was used in the test to investigate system performance during wipe degradation. The test began with a cartridge chambered and full magazine inserted in the weapon, for a total cartridge load of 10 rounds. The suppression mechanisms through both single-wipe and multi-wipe systems are significantly different than in conventional baffle systems:
In conventional baffle systems, expanding combustion gasses are forced through various channels and at least one primary orifice is open to atmosphere at the distal end of the silencer. It is through this orifice that primary blast load is vented, internal pressure blows down, and the system state returns to ambient internal pressure. Hundreds of examples of this phenomenon can be examined in published PEW Science laboratory test reports.
In single-wipe systems, prior to the first shot, the system barrel and silencer internal volumes are closed to atmosphere, other than cursory small vent channels in the weapon chamber. Upon firing of the first shot, precursor flow consisting of both blow-by and compression waves traveling through the barrel air column, forces wipe deformation. The wipe is then punctured by the projectile, whereby expanding combustion gasses can escape to atmosphere. Blast loads are generated in similar fashion as the above conventional case, along with membrane burst loads. These phenomena have been characterized in detail for single-wipe systems in the previously published subsonic 300 BLK test report for the wiped Energetic Armament VOX-S (6.38). In a single-wipe system, the signature is often the most severe during FRP (if the system has poor FRP control), the signature becomes less severe post-FRP, and gradually increases in severity as the single-wipe becomes damaged. This is because the wipe is the sole suppression enhancer in the system; as the wipe is mechanically removed, performance becomes closer to the un-wiped state. This was demonstrated in Report 6.38 through the execution, data reduction, analysis, and engineering calculations from a 20 shot test. As stated above, only the first 5 shots are used in Suppression Rating calculations.
In multi-wipe systems, suppression phenomenology differs significantly from single-wipe systems and also possesses behaviors of conventional systems. Like single-wipe systems, multi-wipe systems still produce membrane burst waves. That phenomenon is demonstrated in this report from the final distal wipe, and occurs even with the pre-scored wipes of the B&T system. Due to the B&T wipe thickness and hardness, the scoring assists with both wipe integrity and projectile directing; wiped system precision on target is generally poor, and anything that can be implemented to perform early correction of mechanically-induced dispersion is typically done. Physically, in early shots where the wipe integrity is closest to pristine, the sudden truncation of pressure propagation results in short duration shocks with relatively expedient rise times. In later shots where wipe integrity has been compromised, load durations are still short, but rise times become longer and amplitudes become lower. As gas expansion efficiency increases from progressive multi-wipe damage allowing staged expansion earlier in time, performance increase post-FRP is observed. This differs from the single-wipe case. Analysis indicates the signature was least severe during the 10th and final wiped shot. B&T AG states that suppression efficiency is reduced after 10 rounds. While PEW Science postulates this may be correct, it could be that suppression efficiency is not reduced until an even higher round count. The trend of signature suppression showed no signs of reversal during the 10th shot, and because wiped suppression often undergoes gradual changes, it is postulated that a set of four virgin B&T wipes may provide more performance during a longer single shot string than 10 rounds, with this particular full power subsonic defense ammunition analog. More testing is needed to investigate this phenomenon; it is relatively uncommon, during intended operation of this type of system, that multiple magazines would be fired in one string.
With all of the above context, it is important to note that the analysis and engineering calculations of the test results of the included wiped silencer also only consider the first 5 shots, as is typical. However, it is important to note that the signature was less severe after the 5th shot and continued to reduce in severity through the tenth and final shot. The computed Suppression Rating does not take this into account, as it is a 5-shot computation.
wIped System General Caution
Wiped systems, configured with a single wipe, or multiple wipes, introduce direct mechanical interference to the bullet flight path within the silencer. Accuracy and precision may be negatively influenced by this mechanical interaction, sometimes significantly. Serious injury or death can result from improper use not in accordance with silencer manufacturer instructions.
This Sound Signature Review contains test results and analysis for two silencers in two tests. Test data was generated using the B&T SIX 9 wiped silencer and Training silencer on the B&T Station SIX 9 bolt-action pistol, chambered in 9mm with a 3.5-inch factory threaded barrel. Speer Lawman 147gr ammunition was used in the tests.
Section 6.174.1 contains the B&T SIX 9 wiped silencer test results and analysis.
Section 6.174.2 contains the B&T SIX 9 Training silencer test results and analysis.
Section 6.174.3 contains Suppression Rating comparisons of the B&T SIX 9 wiped and Training silencers fired on the Station SIX with conventional silencers fired on a conventional 9mm full-size combat handgun, including the Rugged Obsidian 9, CAT SC, SilencerCo Omega 9K, Inert Haze Ti-P, AAC Ti-RANT 9M-HD, AAC Ti-RANT 9M, AAC Ti-RANT 9, HUXWRX CA$H 9K, Resilient Suppressors RSP, CGS MOD9 FS, Rugged Obsidian 45, and SWR Trident-9 silencers.
Section 6.174.4 contains the review summary and PEW Science laboratory staff opinions.
Summary: When paired with the B&T Station SIX 9 bolt-action pistol and fired with Speer Lawman 147gr ammunition, the B&T SIX 9 silencer achieved a Suppression Rating™ of 45.6 in PEW Science testing. The B&T SIX 9 Training silencer with the same host weapon and the same ammunition achieved a Suppression Rating of 40.9. 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
6.174.1 B&T Station SIX 9 Wiped Silencer Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the wiped B&T SIX 9 silencer tested on the B&T Station SIX 9 pistol 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. B&T Station SIX 9 Wiped Silencer Sound Metric Summary
6.174.1.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 10-shot test acquired with PEW-SOFT™ are shown below. One cartridge was loaded into the chamber, nine cartridges were loaded into the magazine and the weapon was fired and manually cycled until the magazine was empty. Only five shots are considered in the analysis. The signatures of all ten shots are displayed in the data presentation but are not included in the analysis to maintain consistency with the overall PEW Science dataset. 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 10 shots with the wiped SIX 9 silencer are shown in Figure 1a. The pressure signatures of Shot 1, Shot 2, and Shot 3 are shown in Figure 1b, in early time.
Fig 1a. B&T Station SIX 9 (Wiped B&T SIX 9 Silencer) subsonic 9x19mm Pistol Muzzle Sound Pressure Signature
Fig 1b. B&T Station SIX 9 (Wiped B&T SIX 9 Silencer) subsonic 9x19mm Pistol Muzzle Sound Pressure Signature
The pressure signatures of Shot 1, Shot 7, and Shot 8, and Shot 9 are shown in Figure 1c, in early time. The real sound impulse (momentum transfer potential) histories from the same 10-shot test are shown in Figure 2a. In Figure 2b, a shorter timescale is shown comparing the impulse of Shots 1 through 3. Figure 2c displays impulse histories of Shot 1, Shot 7, Shot 8, and Shot 9.
Fig 1c. B&T Station SIX 9 (Wiped B&T SIX 9 Silencer) subsonic 9x19mm Pistol Muzzle Sound Pressure Signature
Fig 2a. B&T Station SIX 9 (Wiped B&T SIX 9 Silencer) subsonic 9x19mm Pistol Muzzle Sound Impulse Signature
Fig 2b. B&T Station SIX 9 (Wiped B&T SIX 9 Silencer) subsonic 9x19mm Pistol Muzzle Sound Impulse Signature
Fig 2c. B&T Station SIX 9 (Wiped B&T SIX 9 Silencer) subsonic 9x19mm Pistol Muzzle Sound Impulse Signature
As discussed in the test protocol at the beginning of this report, suppression phenomenology in multi-wipe systems differs significantly from single-wipe systems and also possesses behaviors of conventional systems. The pre-scored wipe pressure propagation is shown after approximately 30.5 ms in Figure 1b. The below performance factors should be noted:
Significant truncation of primary blast load duration (Fig. 1a). This is a result of the multi-wipe system.
FRP divergence is early and severe. This is largely a function of silencer design and not initial wipe puncture, nor membrane burst wave phenomena.
Precursor waves are uniform with primary burst waves exhibiting consistency in both rise time and duration, in both positive and negative phase (Fig. 1b). This trend changes with wipe damage (Fig. 1c).
Primary jetting is of significantly low duration due to the multi-stage wipe configuration. This is significantly different than single-wipe system behavior, as previously discussed.
Later in the string, loss of wipe integrity introduces time lag in rise time (30.7 ms, Fig. 1c). Amplitudes become reduced in both pressure space and impulse space due to enhanced gas expansion stage efficiency from internal wipe damage (Fig. 2b and 2c). “Burst lag” noted in the figure is physical pressure rise-time delay from structural membrane compromise past critical stiffness. The mechanical damage results in less dynamic response, which in turn, results in a less dynamic blast load. Thick wipes, in multiple numbers, perform better when damaged than single thin wipes, for this reason.
PEW Science Research Note 1: The B&T Station SIX 9 system is designed to be compact for its intended use. When size is a design limitation, engineering solutions to gain or maintain efficacy are accomplished with advanced technologies or brute-force implementations such as wiped components. Multi-wipe systems allow for decreased size envelopes with an enhanced ability to trap expanding combustion gasses. With multiple chambers, progressive gas expansion can be tuned to operate with high efficiency, even without the addition of ablative media such as water or grease. Nonetheless, there are physical performance limitations to certain technologies. The size, wipe type, quantity, and configuration of the Station SIX 9 silencer does significantly suppress the weapon system. However, its FRP performance and general suppression performance suffers compared to more advanced modern designs, particularly during the first 5 shots. Note the significant difference between its muzzle (bystander) and shooter’s ear (operator) Suppression Ratings. In this particular case, this phenomenon occurs due to the absence of ejection port blast on the bolt-action system, which directly lowers acute operator risk.
On the webpage link at the top of this report, B&T AG states, in reference to the “Veterinary Pistol SIX,” “The sound produced by the SIX is less than 125 dB. Supersonic ammunition can be used and will have the velocity reduced to subsonic speed by means of a ported barrel.” It is very important to note that the U.S. Station SIX does not possess a ported barrel. Even if the U.S. version of the system did have a ported barrel, it is unlikely that the system would achieve that level of measured suppression, during any portion of the blast load propagation history other than internal initial combustion, with typical factory ammunition, in accordance with the laboratory test data presented in Figures 1 and 2. However, it is also possible that the B&T AG measured blast overpressure value of “125 dB” was acquired at a distance much further than 1.0 meter of standoff. PEW Science laboratory testing of the ported-barrel version of the system is needed to confirm these performance claims.
PEW Science Research Note 2: Significant truncation of blast load duration is a viable suppression mechanism, and one that is clearly demonstrated by the system tested herein. However, gross pressure amplitude and accompanying severity of burst wave negative phase is so severe that hazard reduction through reduced impulse accumulation by reducing the time domain dimension is somewhat nullified. The silencer is simply too small for the technology employed to exhibit the highest levels of performance. There is not enough duration for staged expansion to take place prior to primary distal membrane burst. To be clear, this is a size limitation of the system for this type of technology. This system is intended to be used for an extremely limited number of shots, discretely.
PEW Science Research Note 3: The B&T Station SIX 9 is a bolt-action pistol, and like most bolt-action systems, there is no ejection port blast propagation to contend with; this reduces the blast load signature to both operators and bystanders. Even with its relatively modest muzzle Suppression Rating, the wiped SIX 9 silencer is able to protect the operator with a relatively high shooter’s ear Suppression Rating, facilitated by lack of ejection port blast loading and muzzle blast standoff from the operator’s head due to the standard geometry of a handgun being fired. The shooter’s ear Suppression Rating of the wiped B&T SIX 9 silencer is similar to that from the Resilient Suppressors RSP (6.87) on a full-size semiautomatic combat handgun. As the muzzle Suppression Ratings of the two systems are not significantly different, this provides a direct illustration of the hazards of ejection port blast. The wiped SIX 9 muzzle is closer to the operator, but the level of protection to the operator does not suffer as much due to ejection port blast not propagating from the B&T Station SIX 9 system. It is interesting to note that through the use of advanced technologies, unwiped systems can exceed the performance of wiped systems, even in short length envelopes. For example, the short configuration of the CAT SC (6.162), even with the ejection port blast of the full-size 9mm combat handgun, provides superior free field bystander and operator protection than the wiped SIX 9 silencer on the B&T Station SIX 9. This conclusion is significant and is one example of recent technological advancement in suppressed small arm system performance.
PEW Science Research Note 4: At approximately Shot 5, the B&T Station SIX 9 signature propagation becomes noticeably less severe and calculations from test data support this. As stated at the beginning of this report, the Suppression Rating only considers the first 5 test shots.
PEW Science Research Note 5: Note there is no bolt-closing signature shown in the primary measured free field blast pressure history in Figure 1a. This is because the Station SIX 9 is a bolt-action pistol. Blast pressure blows down from the distal silencer orifice until ambient pressure is reached. The data acquisition time window has been extended to demonstrate the data is acquired in the true free field.
PEW Science Research Note 6: Note that the muzzle Suppression Rating of the B&T Station SIX 9 with the wiped SIX 9 silencer is 35.8 and the shooter’s-ear Suppression Rating is 44.8; which are different zones on the Suppression Rating Dose Chart. Standoff and pressure field shape influence the holistic signature from this weapon system. Examination of waveforms measured at the operator’s head are presented in the Member Version of this report.
Testing and analysis results for the Training silencer on the Station SIX 9 pistol follow:
6.174.2 B&T Station SIX 9 Training Silencer Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the B&T SIX 9 Training silencer tested on the B&T Station SIX 9 pistol is shown in Table 2. The data acquired 1.0 m (39.4 in) left of the muzzle is available for viewing to all. As stated in Section 6.174.1, 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 2. B&T Station SIX 9 Training Silencer Sound Metric Summary
6.174.2.1 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 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 non-wiped B&T SIX 9 Training silencer are shown in Figure 5a. The sound signatures of Shot 1, Shot 2, and Shot 3 are shown in a shorter time window in Figure 5b. The real sound impulse (momentum transfer potential) histories from the same 5-shot test are shown in Figure 6a. In Figure 6b, a shorter timescale is shown comparing the impulse of Shot 1 to that of Shot 2 and Shot 3.
Fig 5a. B&T Station SIX 9 (Non-Wiped Aluminum Baffle B&T SIX 9 Training Silencer) subsonic 9x19mm Pistol Muzzle Sound Pressure Signature
Fig 5b. B&T Station SIX 9 (Non-Wiped Aluminum Baffle B&T SIX 9 Training Silencer) subsonic 9x19mm Pistol Muzzle Sound Pressure Signature
Fig 6a. B&T Station SIX 9 (Non-Wiped Aluminum Baffle B&T SIX 9 Training Silencer) subsonic 9x19mm Pistol Muzzle Sound Impulse Signature
Fig 6b. B&T Station SIX 9 (Non-Wiped Aluminum Baffle B&T SIX 9 Training Silencer) subsonic 9x19mm Pistol Muzzle Sound Impulse Signature
The B&T Station SIX 9 wiped silencer and the SIX 9 training silencer are completely different systems. As such, their blast propagation signatures are also completely different. Significant differences in combustion propagation behavior are noted in the above test data, including:
Significantly longer blowdown duration due to a standard open distal orifice, along with accompanying ground reflection (Fig. 5a).
Typical coupled jet behavior characterized by consistent shock loads at projectile exit (Fig 5b.) with accompanying coincident rarefaction.
Muzzle blast jet pulses, a function of the star baffle geometry in the short design envelope, repeat periodically and in-phase, prior to primary jetting which also appears in-phase (Fig. 5b).
PEW Science Research Note 9: Like the FRP from the included wiped SIX 9 silencer, the FRP generated from the Training silencer is severe. However, its severity differential with subsequent shots is less severe than is the case of the wiped silencer. Although the Training silencer produces a more severe signature than the wiped silencer, its relative FRP severity is reduced. One reason for this is the size of the silencer and the baffle technology used. The signature is severe throughout the shot string; consuming extra air to facilitate ancillary combustion does not adversely influence the signature to the degree it would for a higher performance design. The brute-force suppression of the included wiped silencer traps gas much more efficiently (it does so mechanically).
PEW Science Research Note 10: Flow rate through the Training silencer is relatively high, due to its size and baffle quantity. Combustion propagation is somewhat erratic, even post-FRP. As the intent of the SIX 9 Training silencer is to mimic the size and weight of the included operational wiped SIX 9 silencer, performance may not have been a strong forward design goal.
PEW Science Research Note 11: Comparison of the wiped SIX 9 silencer and the SIX 9 Training silencer, in muzzle Suppression Rating, shows that the first 5 shots of both systems, on average, are not drastically different in severity to an adjacent bystander. This underscores the severe nature of high amplitude but short duration pressure pulses directly adjacent to a pressure orifice. It is not until personnel is moved out of the primary pressure field to the operator’s location that the severity differential between the two systems becomes greater. This comparison is important, because the Training silencer may be used indoors at training facilities; due to the muzzle Suppression Ratings being somewhat comparable between the two systems, initial blast load reflections off of reflecting surfaces may be somewhat similar in amplitude. However, the durations of the blast loads are drastically different, and during the time regime of operation, it is likely that the Training silencer produces a more uncomfortable pressure field for personnel. Supplementary personal protective equipment (PPE) is always encouraged for training purposes by silencer designers, manufacturers, dealers, distributors, and this laboratory.
PEW Science Research Note 12: Flow rate through the Training silencer is relatively high, due to its size and baffle quantity. Combustion propagation is somewhat erratic, even post-FRP. As the intent of the SIX 9 Training silencer is to mimic the size and weight of the included operational wiped SIX 9 silencer, performance may not have been a strong forward design goal. Notably, the SIX 9 Training silencer is just slightly longer than the short configuration of the Rugged Obsidian 9 (6.172) and significantly outperforms it. Granted, the Obsidian 9 was tested on a semiautomatic handgun host. However, the muzzle Suppression Rating differential is severe enough, and the blast propagation physics measured in both tests dictate that the short configuration of the Obsidian 9 would still be significantly outperformed by the SIX 9 Training silencer even if fired with a direct-thread mount on the B&T Station SIX 9 bolt-action pistol. This contextual performance comparison may be valuable for some users. More comparisons are available in Figure 9 in Section 6.174.3 of this report, as well as in the Rankings Section of the Standard. If using the Rankings table, please ensure the B&T Station SIX 9 weapon system is selected, along with your other desired comparison parameters.
Examination of waveforms measured at the operator’s head from the SIX 9 Training silencer are presented in the Member Version of this article.
The following section presents overall comparisons of centerfire pistol silencer configurations on the HK P30L semiautomatic pistol with the B&T Station SIX 9 systems tested and analyzed in this report.
6.174.3 Suppression Rating Comparison (Subsonic 9x19mm from the B&T Station SIX 9 and the HK P30L)
Figure 9 presents a comparison of the PEW Science Suppression Ratings of the included wiped B&T SIX 9 silencer and unwiped B&T SIX 9 Training silencer on the B&T Station SIX 9 and other silencers on the full-size HK P30L semiautomatic pistol using subsonic Speer Lawman 147gr 9mm ammunition. The same ammunition is used in all tests.
Figure 9. Suppression Rating Comparisons of the included wiped B&T SIX 9 silencer and unwiped B&T SIX 9 Training silencer on the B&T Station SIX 9, with the Rugged Obsidian 9, CAT SC, SilencerCo Omega 9K, AAC Ti-RANT 9 Series, the HUXWRX CA$H 9K, Resilient Suppressors RSP, Rugged Obsidian 45, CGS MOD9 FS, and SWR Trident-9 on the HK P30L, Using PEW-SOFT 9x19mm Subsonic Test Data and PEW Science Analysis
PEW Science Research Note 14: Even though the calculated Suppression Rating metrics are universal and may be compared to one another regardless of system (something not possible with other “sound metrics” like “peak dB” transients), in common practice, it is somewhat unusual to compare the performance of silencers on different host weapons. Typically, that results in blurred and potentially misleading comparisons, which can skew user expectations. However, in this case, the decision was made to present the chart in Figure 9 because the B&T Station SIX 9 is a system. Any and all of the above silencers, if fitted with a direct-thread mount, may be installed on the U.S. non-ported barrel B&T Station SIX 9 bolt-action pistol. If that is done, there will be no ejection port blast present during operation. Therefore, it is likely that all of the shooter’s ear Suppression Rating metrics (the blue bars) would increase. It is also possible that muzzle Suppression Rating metrics (the red bars) could also increase, due to severe ejection port blast propagating to the muzzle sensor with conventional pistol systems. Therefore, presentation of the above results should be viewed with this context in mind. An abbreviated contextual caution is also present in the Figure legend. It is therefore our hope that the likelihood for misuse, misunderstanding, and non-contextual use of the data in this chart is low.
With the above context in mind, the overall suppression performance of the B&T Station SIX 9 system, regardless of wiped or Training silencer, is lower than may be anticipated by many users, due to general interpretation of marketing and mystique of the intended purpose of such a system. As iterated several times in this report, the performance of the system does increase during Shot 5 and through Shot 10. However, the Suppression Rating calculation is always computed with five shots; to skew the calculation for a wiped test (like the previous VOX-S 300 BLK wiped test) or this test, would invalidate comparisons across the pedigree. Therefore, the standard 5-shot Suppression Rating calculation stands and is not adjusted, despite the wiped SIX 9 silencer exhibiting higher late-shot-string performance. Furthermore, as a note of practicality, users generally judge suppression performance by the initial shots; not by an arbitrarily late shot sequence requiring additional magazines, for example. Including 10 shots would hamper practical utility and also dilute FRP contribution to the Suppression Rating, which is, again, unacceptable for the research pedigree. This is particularly the case for the Station SIX 9, which has significantly severe FRP.
PEW Science Research Note 15: The closest overall performance to the wiped SIX 9 system, on average, based on free field blast hazard risk, is the Resilient Suppressors RSP (6.87), based on the presented data. Clearly, the two systems are extremely different and produce extremely different signatures; one being fired on a reciprocating system with ejection port blast, the other being fired on a bolt-action system with only one primary blast overpressure source to atmosphere. The systems are different, they behave differently, and they sound different, and the blast load durations are significantly different. Nonetheless, in the true free field, the acute risk to operators and bystanders is calculated to be very similar. This is how the Suppression Rating metrics are used. They are not subjective metrics; they are objective risk calculations and are only valid in the true free field away from reflecting surfaces other than the ground. This is the only way to provide apples-to-apples comparisons with blast load analysis. Various environmental testing is a subject of ongoing PEW Science laboratory research.
As previously discussed, it is interesting to note that through the use of advanced technologies, unwiped systems can exceed the performance of wiped systems, even in short length envelopes. For example, the short configuration of the CAT SC (6.162), even with the ejection port blast of the full-size 9mm combat handgun, provides superior free field bystander and operator protection than the wiped SIX 9 silencer on the B&T Station SIX 9. This conclusion is significant and is one example of recent technological advancement in suppressed small arm system performance.
Notably, the unwiped SIX 9 Training silencer is just slightly longer than the short configuration of the Rugged Obsidian 9 (6.172) and significantly outperforms it. Granted, the Obsidian 9 was tested on a semiautomatic handgun host. However, the muzzle Suppression Rating differential is severe enough, and the blast propagation physics measured in both tests dictate that the short configuration of the Obsidian 9 would still be significantly outperformed by the SIX 9 Training silencer even if fired with a direct-thread mount on the B&T Station SIX 9 bolt-action pistol. This contextual performance comparison may be valuable for some users.
The shooter’s ear Suppression Ratings of some silencers in Figure 9 are similar. This does not mean that the overall signature of the weapon system is identical. It means that the hearing damage risk to the shooter is almost identical, in the free field. Environmental changes and deviations from free field conditions can, and most likely will, result in protection differentials that shift. Severe environmental differentials may provide severity with highly nonlinear characteristics and outcomes. PEW Science highly encourages examination of the full member version of this report for elaboration on these performance facts.
PEW Science Research Note 16: 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, silencers with a lower Suppression Rating are postulated to be more hazardous to the unprotected ear than silencers with a higher Suppression Rating. To iterate, the Suppression Rating is a DRC - it is not a subjective quantity; it is an objective quantification of hearing damage risk potential.
6.172.4 Review Summary: B&T Station SIX 9 Wiped and Training Silencers on the B&T Station Station SIX 9 Bolt-Action Pistol
When paired with the B&T Station SIX 9 bolt-action pistol and fired with Speer Lawman 147gr ammunition, the B&T SIX 9 silencer achieved a Suppression Rating™ of 45.6 in PEW Science testing. The B&T SIX 9 Training silencer with the same host weapon and the same ammunition achieved a Suppression Rating of 40.9.
As with all weapon systems, the user is encouraged to examine both muzzle and ear Suppression Ratings.
PEW Science Laboratory Staff Opinion:
The B&T Station SIX 9 is a bolt-action pistol that includes a wiped silencer. The overall package is compact, may be used discretely in both spent casing ejection and overall signature, and modified to break-down to a very compact configuration through grip modification. The U.S. version of the pistol has a non-ported barrel that is threaded 1/2”-28tpi and may be used with direct-thread silencers of users’ choosing. While the gross sound suppression performance of the included wiped SIX 9 silencer is not extremely high, it does significantly suppress the system when compared to an unsuppressed gunshot, particularly for its size. As the silencer wipes are consumable parts, B&T also offers a separate Training silencer of identical dimensions. The performance of the SIX 9 Training silencer is somewhat similar to that of the wiped SIX 9 silencer, though lower.
The B&T Station SIX 9 was developed by B&T AG for the following public purpose (direct-quote):
“B&T developed the SIX in response to requests from Swiss veterinarians that required a very quiet firearm for dispatching sick cattle or game injured along the motorway without disturbing the other animals or residence in the area. The development goal was to have quietest possible sound but with sufficient energy to dispatch a large bovine animals quickly with a low risk of ricochet or over penetration.”
Regardless of the intended purpose of the weapon system, suppressed small arm weapon systems, in general, may be used for such a purpose. The Station SIX 9 has other features that exceed the above use goal, and users may find the features welcome. Such features include the ability to catch a spent cartridge case in the support hand during ejection with the support hand thumb actuating the grip safety to rotate the bolt. Another feature is a pre-scored grip module on the main pistol frame that may be cut such that storage of the pistol without a magazine inserted is more compact. Although the barrel of the U.S. Station SIX 9 is not ported like the Swiss VP9, the ability to use modern high-performance silencers on the U.S. Station SIX 9 may be attractive to some users, depending upon their use case. Significantly higher performance can be gained by using a modern 9mm pistol silencer on the Station SIX 9, instead of the included wiped silencer. Many times, this incurs a weight or length penalty. However, not always.
The shooter’s ear Suppression Rating of the wiped B&T SIX 9 silencer is similar to that from the Resilient Suppressors RSP on a full-size semiautomatic combat handgun. As the muzzle Suppression Ratings of the two systems are not significantly different, this provides a direct illustration of the hazards of ejection port blast. The wiped SIX 9 muzzle is closer to the operator, but the level of protection to the operator does not suffer as much due to ejection port blast not propagating from the B&T Station SIX 9 system. It is interesting to note that through the use of advanced technologies, unwiped systems can exceed the performance of wiped systems, even in short length envelopes. For example, the short configuration of the CAT SC, even with the ejection port blast of the full-size 9mm combat handgun, provides superior free field bystander and operator protection than the wiped SIX 9 silencer on the B&T Station SIX 9. This conclusion is significant and is one example of recent technological advancement in suppressed small arm system performance. Notably, the SIX 9 Training silencer is just slightly longer than the short configuration of the Rugged Obsidian 9 and significantly outperforms it. Granted, the Obsidian 9 was tested on a semiautomatic handgun host. However, the muzzle Suppression Rating differential is severe enough, and the blast propagation physics measured in both tests dictate that the short configuration of the Obsidian 9 would still be significantly outperformed by the SIX 9 Training silencer even if fired with a direct-thread mount on the B&T Station SIX 9 bolt-action pistol. This contextual performance comparison may be valuable for some users.
Operationally, the B&T SIX 9 can be somewhat frustrating to use for two primary reasons. The first is bolt actuation. Depressing the grip safety is required for bolt operation, and chambering a round often results in misfeeds in which new cartridges fall out of the chamber. This occurred during initial testing trials of the silencer and has been duplicated by system users. Fortunately, the ejection port may be cupped by the support hand, which can alleviate some issues. Secondly, the ergonomics of the system, along with the trigger pull, are not as user-friendly as well-developed 9mm combat handguns. These opinions are from PEW Science laboratory staff and may not represent the user-base at large.
The star-baffle geometry in the Training silencer, with U.S. lineage in design origin, is an interesting historical note. It is somewhat well known that B&T AG has utilized crimped-cone design lineage in machined baffles in several silencer models; for elements of the design to also be placed in the SIX 9 Training silencer is a testament to the wide proliferation of early U.S. silencer technology innovation.
In this review, the B&T Station SIX 9 wiped and Training silencer performance metrics depend upon suppressing a bolt-action handgun firing a full-power subsonic centerfire pistol cartridge. This type of evaluation provides a specialized look at personnel risk and operational physics due to the unique design factors of the host weapon. PEW Science encourages the reader to carefully consider action dynamics, barrel lengths, and other characteristics in the selection of centerfire pistol silencer hosts and systems.
The hearing damage potential of centerfire pistol 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. Note that the presence of nearby reflecting surfaces, as well as ammunition choice, can influence the sound signature to which both the shooter and bystanders are subjected.
