SSS.8.1.18 - Suppressed Bolt Action Rifle Hazards - AAC 762-SDN-6 Silencer Hazard Map Brief
/AAC 762-SDN-6 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 AAC 762-SDN-6 rifle silencer fielded on an 8-in barrel 300 BLK bolt action rifle firing subsonic 190gr 300 BLK ammunition, as evaluated in technical Report 6.221 and as tabulated in record number 7.1.252 in the Rankings.
The average Suppression Rating hazard contours at 1.6 m silencer end cap elevation from the instrumented blast test of the AAC 762-SDN-6 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.
8.1.18.1 PEW-SOFT HD Computational Model Parameters
PEW-SOFT HD code Version 2.2.7 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 0.357.
8.1.18.2 AAC 762-SDN-6 Suppression Hazard Map Observations:
Unlike the legacy version of the silencer, the AAC 762-SDN-6 is a hybrid design with high flow rate, maintaining high performance signature suppression. The silencer controls blast propagation relatively well, especially for a high flow rate silencer with low pressure combustion input in the subject evaluation. 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.
Forward field severity is very extremely low 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.
The hazard field from the AAC 762-SDN-6 system is consistent from shot to shot, from FRP onward. The FRP hazard differential from the silencer is low.
fig 1. AAC 762-SDN-6 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
