SSS.8.1.35 - Suppressed Bolt Action Rifle Hazards - PTR VENT 1 Silencer Hazard Map Brief
/PTR VENT 1 on an 8-in Barrel subsonic 300 BLK Bolt Action Rifle - Hazard Map
This Silencer Hazard Map Brief documents the free field blast overpressure hazards from the PTR VENT 1 rifle silencer fielded on an 8-in barrel 300 BLK bolt action rifle firing subsonic 190gr 300 BLK ammunition, as evaluated in technical Report 6.238 and as tabulated in record number 7.1.279 in the Rankings.
The average Suppression Rating hazard contours at 1.6 m silencer end cap elevation from the instrumented blast test of the PTR VENT 1 silencer computed with the PEW-SOFT HD Blast Hazard Prediction Tool are shown in Figure 1. The Suppression Rating hazard scale is shown in Figure 2. Ground-truth anchored Suppression Ratings from the technical report 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.
8.1.35.1 PEW-SOFT HD Computational Model Parameters
PEW-SOFT HD code Version 2.2.8 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 bolt action jet stability index sigma_b of the silencer is 0.48.
8.1.35.2 PTR VENT 1 Suppression Hazard Map Observations:
The PTR VENT 1 produces very high performance signature suppression. The silencer controls blast propagation exceptionally well and creates a relatively low risk hazard field around both the weapon system and operator. Blast load input into the silencer is relatively low amplitude due to the use of subsonic 300 BLK in the test, but relatively high amplitude for that combustion regime due to the short 8-in rifle barrel. Blast load output from the silencer is very controlled, with relatively stable jetting. Jet momentum is expelled from the silencer at a somewhat higher rate for this level of signature suppression due to the nature of the early time blast loads progressing through the PIP lattice.
Forward field severity is very extremely low even compared with that from competing 300 BLK systems of similar size. Severity in the rear field near the operator is also low and bolt action weapon system operator hazards are lower for this combustion regime than they are with a semiautomatic weapon system (e.g. AR-15 or AR-18). Forward field dispersion from silencer jetting is relatively controlled. Note that operator risk is driven by multiple sources of sound and overpressure from the weapon system. At these levels of suppression, resonance plays a role in audible signature.
The hazard field from the PTR VENT 1 system is very consistent from shot to shot. The FRP hazard differential from the silencer is low.
fig 1. PTR VENT 1 8-in barrel 300 BLK Subsonic Bolt-Action 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
