SSS.6.29 - Q Half Nelson and the Q mini FIX 300 BLK Subsonic
/Q Half Nelson on a Q mini FIX 300 BLK with 8-in Barrel
The Half Nelson is designed and manufactured by Q. 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 1.75-inch diameter and is 6.85 inches in length. The silencer is available as a 5/8”-24tpi 25-degree tapered direct-thread model. The silencer is tubeless and constructed of titanium. The silencer weighs 12.2 ounces. The Half Nelson can be obtained from Silencer Shop.
This review contains single-test results using the Half Nelson on the Q mini FIX bolt action pistol, chambered in 300 BLK with an 8-inch barrel. Discreet Ballistics 190gr ammunition was used in the test.
Summary: When paired with the Q mini FIX 8” 300 BLK and fired with Discreet Ballistics 190gr Subsonic Target ammunition, the direct-thread Q Half Nelson achieved a Suppression Rating™ of 55.6 in PEW Science testing.
The performance of the direct-thread Half Nelson on supersonic .308 is similar to that of the “Cherry Bomb” muzzle device-equipped Q Trash Panda, which is detailed in the previous PEW Science Sound Signature Review 6.4, in which the Trash Panda achieved a Suppression Rating of 33.1.
6.29.1 Half Nelson Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Half Nelson 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. Q Half Nelson Sound Metric Summary
6.29.1.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 5-shot test acquired with PEW-SOFT™ are shown below. The waveforms are not averaged, decimated, or filtered. The data acquisition rate used in all PEW Science 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, here.
Figure 1 shows a 2-millisecond long sequence of events during the first test shot of the Half Nelson, as measured 1.0 m left of the muzzle. There are six significant events shown:
During firing system manipulation (trigger and striker actuation) the signature reaches a 107.3 dB amplitude.
The next peak of 117.7 dB occurs during combustion within the weapon system.
Subsequent first round combustion inside the silencer produces a peak amplitude of 117.5 dB.
As the pressure pulse exits the silencer, an initial peak of 133.9 dB is measured.
Jetting increases out of the silencer end-cap, and a 142.4 dB peak occurs.
The maximum peak pressure amplitude of the first shot is measured to be 142.7 dB.
This is a somewhat atypical sequence observed when firing subsonic 300 BLK ammunition from a bolt-action weapon system with an attached silencer. Internal silencer design can significantly influence the measured timing and pressure amplitudes.
Fig. 1 Early-Time Shot History, Q Half Nelson Bolt Action 300 BLK Muzzle Sound Pressure Signature, 24-OCT-2020
To examine the Q Half Nelson first round sound signature characteristics in context, the reader is encouraged to also review the test results of the Energetic Armament VOX S with the same host weapon and ammunition in Sound Signature Review 6.25. One notable difference between the early-time signatures of the two silencers with subsonic 300 BLK is the longer duration of the internal silencer combustion event; this event beginning at approximately 29.6 ms in Figure 1 directly illustrates the influence of increased silencer volume during combustion when firing subsonic ammunition, prior to gas leaving the silencer. There are other significantly different early-time signature characteristics as well, to include delayed first round gas jetting with the Half Nelson, which result in different suppression performance. Overall subsonic 300 BLK performance comparisons of the two silencers are shown in Section 6.29.2 of this review.
The primary sound signature pressure histories for all 5 shots are shown in Figure 2a. A zoomed-in timescale displays the region of peak sound pressure in Figure 2b. The real sound impulse (momentum transfer potential) histories from the same 5-shot test are shown in Figure 3. Again, full and short timescales are shown.
Fig 2a. Q Half Nelson Bolt Action 300 BLK Muzzle Sound Pressure Signature, 24-OCT-2020
Fig 2b. Q Half Nelson Bolt Action 300 BLK Muzzle Sound Pressure Signature, Short Time Window, 24-OCT-2020
Figure 3a. Q Half Nelson Bolt Action 300 BLK Muzzle Sound Impulse Signature, 24-OCT-2020
Figure 3b. Q Half Nelson Bolt Action 300 BLK Muzzle Sound Impulse Signature, 24-OCT-2020
Figure 2 shows a significant pressure regime first-round-pop (FRP). Figure 3 shows the same phenomenon in impulse space. The first round pop is postulated to be noticeable to bystanders, as determined by PEW Science inner-ear response analysis.
An interesting behavior noted in the muzzle measurements are the combined end-cap exit and jetting events of each shot at approximately 29.9 ms. These events are extremely consistent between shots and the fast rise-time of the pressure pulses are similar to that of the initial pulses measured during supersonic testing of the Q Trash Panda in Sound Signature Review 6.4. This fast rise-time is most likely predominantly due to the bore aperture size of the silencer being large relative to several silencers tested by PEW Science, to date, and the subsequently higher gas flow rate.
PEW Science Note 1: The early-time pressure pulses, although consistent, are eclipsed by the FRP in Shot 1; PEW Science testing indicates that .30 silencers in the size range of the Half Nelson may exhibit significant FRP in the subsonic flow regime. After the extremely consistent early-time behavior, which is also noted in impulse space prior to a time of 30 ms, the faster rise time and significant relative impulse amplitude of Shot 1 is observed. It is important to note that the similar Trash Panda did not exhibit significant FRP in the supersonic flow regime and PEW Science testing of the Half Nelson in the supersonic flow regime indicates it also does not exhibit significant FRP. The FRP of the Half Nelson is therefore observed to be a phenomenon only occurring below a certain sound pressure threshold in PEW Science testing, to date. The Energetic Armament VOX S also exhibited significant FRP in the subsonic flow regime, whereas it’s supersonic FRP was less pronounced. Note that supersonic 7.62x51mm behavior is not necessarily an indicator of behavior with supersonic 300 BLK. This is a subject of future data publication.
PEW Science Note 2: 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.
The sound signature of the Half Nelson when suppressing subsonic 300 BLK significantly differs from its signature when suppressing supersonic .308. While the peak sound pressure is lower in this test, the impulse is significantly lower than measured in the .308 test. This phenomenon is a result of the significantly different propellant loads of the 300 BLK and .308 / 7.62x51mm cartridges.
6.29.1.2 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 4. The primary sound signature history is shown on the left. A zoomed-in timescale is displayed on the right, in the region of peak sound pressure. The real sound impulse (momentum transfer potential) histories at the ear from the same 5-shot test are shown in Figure 5. Full and short timescales are shown.
Figure 4a. Q Half Nelson Bolt Action 300 BLK Ear Sound Pressure Signature, 24-OCT-2020
Figure 4b. Q Half Nelson Bolt Action 300 BLK Ear Sound Pressure Signature, Short Time Window, 24-OCT-2020
Figure 5a. Q Half Nelson Bolt Action 300 BLK Ear Sound Impulse Signature, 24-OCT-2020
Figure 5b. Q Half Nelson Bolt Action 300 BLK Ear Sound Impulse Signature, 24-OCT-2020
Similar to the measurements at the muzzle, there is significant FRP evident when examining the waveforms measured at the shooter’s ear, and this is clearly observed in both Figure 4b and Figure 5b. Note that, again, the fast rise-time to peak impulse after silencer gas exit is evident in Shot 1. Also note the very similar pressure and impulse magnitudes during Shot 1 and Shot 2 prior to the gas completely exiting the weapon system. Even the subsonic 300 BLK platform creates measurable sound signature even before the gas completely exits the barrel and silencer.
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 significantly lower impulse at the shooter’s ear in this test when compared to that in the .308 test of the Trash Panda.
PEW Science Note: The sound signature at the ear with the Half Nelson when firing subsonic 300 BLK on the Q mini FIX is significantly quieter than with the Energetic Armament VOX S. This is evident in both pressure and impulse measurements, as well as in detailed PEW Science inner-ear response analysis, which is the subject of future PEW Science Member Research publication.
6.29.2 Suppression Rating Comparison - Subsonic 300 BLK
The Q Half Nelson suppressor is intended to possess significant sound suppression performance for its size in the subsonic flow regime. Figure 6 shows a performance comparison of the two .30 rifle silencers tested with the subsonic 300 BLK cartridge shown in public PEW Science testing, to date. Unsuppressed and suppressed sound signature ratings are shown for both the shooter and bystanders.
Figure 6. Suppression Rating Comparisons Of .30 Rifle Silencers Using PEW-SOFT Data 300 BLK Subsonic Test Data
Note that the performance of the Q Half Nelson at the weapon muzzle, which is an indicator of nearby bystander sound signature perception, is higher than that of the Energetic Armament VOX S. At the shooter’s ear, the performance of the Half Nelson is significantly higher than that of the VOX S; the difference in Ear Suppression Rating is almost 10 points (a Suppression Rating category-spanning range), indicating that shooters firing subsonic ammunition through the tested host weapon with the Half Nelson will experience a significantly quieter sound signature than with the VOX S. The Half Nelson is an objectively quieter silencer than the VOX S in both the supersonic and subsonic flow regimes. Bolt-action host weapon testing allows strict isolation of sound suppression performance variables.
Performance of these silencers on semi- and fully-automatic 300 BLK host weapons is the subject of future PEW Science research. Back pressure relationships of the silencers in the supersonic flow regime can be examined in previous PEW Science test reports of the Trash Panda and VOX S. The Half Nelson, like the Trash Panda, is postulated to possess lower back pressure than the VOX S, based on rise-time to peak impulse parameters (flow rate). Back pressure characteristics present in the supersonic and subsonic flow regimes are the subjects of ongoing PEW Science research. PEW Science members help fund such research efforts; PEW Science thanks you for your support.
6.29.3 Review Summary: Q Half Nelson on a Q mini FIX 300 BLK with 8-in Barrel
When paired with the Q mini FIX 8” 300 BLK and fired with Discreet Ballistics 190gr Subsonic Target ammunition, the direct-thread Q Half Nelson achieved a Suppression Rating™ of 55.6 in PEW Science testing.
The performance of the direct-thread Half Nelson on supersonic .308 is similar to that of the “Cherry Bomb” muzzle device-equipped Q Trash Panda, which is detailed in the previous PEW Science Sound Signature Review 6.4, in which the Trash Panda achieved a Suppression Rating of 33.1.
PEW Science Subjective Opinion:
The Q Half Nelson is a compact, lightweight, and simple high-performance subsonic .30 rifle silencer with respectable performance in the supersonic flow regime for its size, like its sister silencer, the Trash Panda. The Half Nelson is a direct-thread model, and cannot be used with the Cherry Bomb muzzle brake. Although the direct-thread interface of the silencer possesses a 25-degree taper for use on tapered-barrel muzzles, the silencer can also attach to standard 90-degree shoulder muzzles due to adequate surface area at the mount interface.
The simple ported cone-baffle tubeless design of the Half Nelson (and Trash Panda) silencers is observed to exhibit extremely efficient subsonic sound signature performance for the design envelope. The Suppression Rating Performance delta between the Half Nelson and the Energetic Armament VOX S, for example, is significant at the shooter’s ear; detailed waveform and inner-ear response comparisons of the two silencers is the subject of a future PEW Science Member Research Supplement.
First round pop (FRP) performance in the subsonic flow regime is lower with silencers in the size class of the Half Nelson. PEW Science testing indicates that subsonic FRP is challenging to eliminate with compact silencers; comparisons will be provided in future PEW Science data publications.
Many of the performance characteristics of the Half Nelson are shared with that of the Trash Panda; the notable differences are that of the direct-thread interface instead of the muzzle brake attachment threading and an extra baffle in the Half Nelson. It is interesting to note that the extra baffle of the Half Nelson does not seem to significantly influence its supersonic performance when compared to that of the Trash Panda. Further PEW Science testing is needed to fully quantify the performance differences in the subsonic flow regime.
Note that the Cherry Bomb muzzle brake used with the Trash Panda is heat-treated stainless steel; the combustion products produced on various barrel lengths influence the heat, abrasion, and other phenomena incurred by the blast-baffle interface of a silencer. As a result, the user is encouraged to consider their use case(s) when selecting a direct-thread silencer or a muzzle brake mounted silencer, as muzzle brake mounts like the Cherry Bomb can serve as “sacrificial” blast baffles on certain host weapons such as short-barrel semi-automatic rifles. As the Half Nelson and Trash Panda are both constructed of titanium, users should be mindful of their firing schedules and barrel lengths. Users with less severe firing schedules or longer barrels may choose to use the Half Nelson instead of the Trash Panda. Note that using the Half Nelson with a tapered barrel provides for a very simple, repeatable, and secure attachment mechanism. This is the case with all 25-degree tapered direct-thread silencers.
In this review, the Half Nelson performance metrics depend upon suppressing a subsonic intermediate rifle cartridge. While the sound signature of such cartridges can be suppressed to levels that may result in the desire of the shooter and bystanders to not wear hearing protection, PEW Science encourages the reader to remain vigilant with regard to all subsonic rifle cartridge suppression claims. The gas volume and combustion products created by firing a subsonic intermediate rifle cartridge such as 300 BLK are still significant; the measured pressure and impulse magnitudes, and their durations, illustrate this fact.
The hearing damage potential of subsonic rifle use is not insignificant. PEW Science encourages the reader to consider the Suppression Rating when deciding on an appropriate silencer and host weapon combination for their desired use.
