SSS.8.1.4 - Suppressed AR-15 Rifle Hazards - Battle Born Supply Co. Whiskey Quebec 5.56 Silencer Hazard Map Brief
/Battle Born Supply Co. Whiskey Quebec 5.56 Models on the M4A1 Mid-Gas 5.56x45mm 14.5-in Barrel Automatic AR15 Rifle - Hazard Maps
This Silencer Hazard Map Brief documents the free field blast overpressure hazards from the Battle Born Supply Co. Whiskey Quebec 5.56 silencers (Purged and non-purged) fielded on the 14.5-in M4A1RIII AR-15 semiautomatic rifle firing M193 55gr 5.56 NATO ammunition, as evaluated in technical Report 6.206 and Report 6.207 and as tabulated in record numbers 7.1.234 and 7.1.235 in the Rankings, respectively.
The average Suppression Rating hazard contours at 1.6 m silencer end cap elevation from the instrumented blast test of the non-purged version of the silencer computed with the PEW-SOFT HD Blast Hazard Prediction Tool are shown in Figure 1. Hazard contours for the Purged version of the silencer are shown in Figure 2. The Suppression Rating hazard scale is shown in Figure 3. Ground-truth anchored Suppression Ratings from the technical reports are annotated 1.0 m left of the end cap (SR_muzzle) and 6 inches right of the shooter’s right ear (SR_ear). Computational parameters and blast overpressure hazard field observations are provided below.
8.1.4.1 PEW-SOFT HD Computational Model Parameters
PEW-SOFT HD code Version 2.2.4 Alpha was used.
Contour elevation is 1.6 m above grade. No reflecting surfaces, other than the ground, are present in the model.
Grid resolution is 0.076 m (3 in).
The average semiautomatic jet stability index sigma_sa of the non-purged version is 0.0658. The Purged version of the silencer has a lower jet stability index of 0.0508.
8.1.4.2 Whiskey Quebec 5.56 Models Suppression Hazard Map Observations:
The Whiskey Quebec 5.56 silencer series are full size, 2-in diameter hybrid designs with high early time flow rate. The Purged model possesses higher late time flow rate than the standard model. Blast load input into the silencers is relatively high amplitude from the 14.5-in rifle barrel. Blast load output from the silencers is generally controlled, with the non-purged model producing a more stable jet. The stability index of the Purged model drops due to its distal vent array.
Near-field severity forward of the operator is generally less intense and less hazardous with the non-purged model. The Purged model produces safer near-field severity near the weapon operator. These hazard field differentials are driven by reduced ejection port blast hazards with the Purged model, along with its somewhat elevated muzzle blast hazards.
Both silencer models provide relatively consistent hazard fields after the first shot. Blowdown momentum is significantly controlled.
fig 1. Battle Born Supply Co. Whiskey Quebec 5.56 14.5-in M4A1 AR-15 Free Field Hazard Map Produced by PEW-SOFT HD Blast Hazard Prediction Tool using PEW Science Test Data
fig 2. Battle Born Supply Co. Whiskey Quebec 5.56 Purged 14.5-in M4A1 AR-15 Free Field Hazard Map Produced by PEW-SOFT HD Blast Hazard Prediction Tool using PEW Science Test Data
Fig 2. PEW Science Suppression Rating Scale
