CAT SP in Long and Short Configurations on the 1911 Full-Size Semiautomatic .45 ACP Pistol - Hazard Map

This Silencer Hazard Map Brief documents the free field blast overpressure hazards from the CAT SP silencer in both its long and short configurations fielded on the 1911 semiautomatic combat handgun firing Speer Lawman 230gr .45 ACP ammunition, as evaluated in technical Report 6.242 and as tabulated in record numbers 7.1.286 and 7.1.287 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 long configuration of the CAT SP silencer computed with the PEW-SOFT HD Blast Hazard Prediction Tool are shown in Figure 1. Similarly, the hazard contours with the short configuration 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) on both maps. Computational parameters and blast overpressure hazard field observations are provided below.

8.1.39.1 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 semiautomatic jet stability index sigma_sa of the long configuration of the silencer is 0.99. The index for the short configuration of the silencer is 0.47.

8.1.39.2 CAT SP Suppression Hazard Map Observations:

The CAT SP is a modular silencer that produces highly controlled blast load propagation and varying hazard fields based on its configuration. Blast load input amplitude into the silencer may be considered moderate, as the barrel length of the 1911 is 5.5 inches long. In its long configuration, blast load output is exceptionally controlled, combining a high early-time flow rate with high distal momentum control. This creates a hazard field that is globally less severe than most other .45 ACP silencers evaluated on a standard combat handgun, to date.

In the long configuration, personnel risk in both the forward field and rear field near the operator is reduced to levels surpassing even the legacy AAC Ti-RANT 45. Because the CAT SP maintains an extremely high early-time flow rate, system back pressure is very low, which significantly reduces ejection port blast load propagation, especially when paired with the favorable lock time mechanics of the linked tilting barrel in the 1911 pistol. When converted to the short configuration by removing the front section, early-time flow rate and ejection port blast reduction remain identical, but late-time flow rate increases significantly. Consequently, muzzle blast severity increases . However, due to the maintained low early-time back pressure and hazard field shape differences, net operator risk in the rear field drops much less severely, allowing the short CAT SP to maintain more operator protection than typical

Both the long and short configurations of the CAT SP provide highly consistent hazard fields from shot to shot, with first-round-pop (FRP) effectively masked across the entire shot string.