#Subsonic 556 db full

This phenomenon is a result of the significantly different propellant loads of the 300 BLK and. While the peak sound pressure is lower in this test, the impulse is significantly lower than measured in the. The sound signature of the Half Nelson when suppressing subsonic 300 BLK significantly differs from its signature when suppressing supersonic. This is one of the reasons why The Silencer Sound Standard requires examining multiple sound signature metrics. The FRP phenomenon cannot always be shown by viewing only the peak sound pressure. PEW Science Note 2: First-round sound signatures always differ from subsequent shots, as the atmosphere within the silencer changes. This is a subject of future data publication. Note that supersonic 7.62x51mm behavior is not necessarily an indicator of behavior with supersonic 300 BLK. The Energetic Armament VOX S also exhibited significant FRP in the subsonic flow regime, whereas it’s supersonic FRP was less pronounced. 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. It is important to note that the similar Trash Panda did not exhibit significant FRP in the supersonic 7.62x51mm flow regime and PEW Science testing of the Half Nelson in the same supersonic flow regime indicates it also does not exhibit significant FRP. 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. 30 silencers in the size range of the Half Nelson may exhibit significant FRP in the subsonic flow regime. PEW Science Note 1: The early-time pressure pulses, although consistent, are eclipsed by the FRP in Shot 1 PEW Science testing indicates that. 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. 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. The first round pop is postulated to be noticeable to bystanders, as determined by PEW Science inner-ear response analysis.Īn interesting behavior noted in the muzzle measurements are the combined end-cap exit and jetting events of each shot at approximately 29.9 ms. Figure 3 shows the same phenomenon in impulse space.

#Subsonic 556 db full

Again, full and short timescales are shown.įigure 2 shows a significant pressure regime first-round-pop (FRP). The real sound impulse (momentum transfer potential) histories from the same 5-shot test are shown in Figure 3. A zoomed-in timescale displays the region of peak sound pressure in Figure 2b. The primary sound signature pressure histories for all 5 shots are shown in Figure 2a. Overall subsonic 300 BLK performance comparisons of the two silencers are shown in Section 6.29.2 of this review. 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. 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. 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.