Tuna Cans Blackfin XL 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 modular Tuna Cans Blackfin XL rifle silencer fielded on an 8-in barrel 300 BLK bolt action rifle firing subsonic 190gr 300 BLK ammunition in the 12-baffle and 9-baffle configuration, as evaluated in technical Report 6.241 and as tabulated in record numbers 7.1.284 and 7.1.285 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 Tuna Cans Blackfin XL silencer in the 12-baffle configuration computed with the PEW-SOFT HD Blast Hazard Prediction Tool are shown in Figure 1, whereas the 9-baffle configuration is shown in Figure 2. The Suppression Rating hazard scale is shown in Figure 3. 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.

8.1.38.1 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 12-baffle configuration of the silencer is 0.29 and the index of the 9-baffle configuration is 0.32.

8.1.38.2 Tuna Cans Blackfin XL Suppression Hazard Map Observations:

The Tuna Cans Blackfin XL utilizes a "brute force" approach to signature suppression, producing varying hazard fields based on its modular configuration. 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. In its full 12-baffle configuration, the silencer controls post-FRP blast propagation relatively well due to its significant length and expansion volume, creating a relatively low-risk hazard field around the weapon system and operator. However, due to its baffle design and .375 caliber over-bore, blast load output from the silencer during the first shot is unoptimized, presenting a severe initial jetting event with a high rate of momentum accumulation.

Forward field severity in the 12-baffle configuration is very low after the first shot, though the initial blast propagates with significant impulsivity. Severity in the rear field near the operator is mitigated in the 12-baffle configuration due to the extended standoff distance of the 10.6-inch system. When reduced to the 9-baffle configuration, the hazard field broadens significantly, and gas velocity out of the end of the silencer increases. This shifts the hazard field shape, increasing relative risk more severely in the rear field than adjacent to the muzzle. Operator risk is driven significantly higher in the shorter configuration due to this reduced standoff distance and elevated blast load amplitude.

The hazard field from the Tuna Cans Blackfin XL system is heavily influenced by severe first-round-pop (FRP). In the 12-baffle configuration, the bystander FRP hazard differential is extreme, presenting a signature that may be upward of four times as severe as subsequent shots. In the 9-baffle configuration, the operator experiences an extremely severe FRP hazard that approaches the relative bystander FRP severity of the full-size configuration. After this initial severe jetting, subsequent shots in both configurations present highly consistent, controlled blast momentum.