The flechette shotgun ammunition tested was a random sample taken from production and fired from a government issue Mossberg M-590 shotgun with 20 inch barrel and cylinder bore choke held in a supported shooting rest. The target was an FBI standard synthetic ballistic gel block measuring 6 X 6 X 16 inches manufactured by Clear Ballistics Inc. The ballistic gel was calibrated by the manufacturer to FBI ammunition test standards, a steel BB fired at 600 FPS penitrating between 2.95 and 3.74 inches. The ballistic gel block used in this test had a penetration calibration of 3.25 inches. The ballistic gel target range used was 10 feet/3.33 yards/3.048 meters as specified in the FBI ammunition test protocol. The flechette sabot ammunition tested had a velocity on impact of 1950 FPS (feet per second).
The flechette shotgun ammunition supersonic impact velocity of 1950 FPS is equivalent to mach 1.75, the supersonic cavitations for the multiple flechette impact is shown overlaid with a 1 inch by 1 inch grid. Each flechette striking the ballistic gel block creates an individual supersonic cavitation along the flight path within the ballistic gel as it passed through the target. Each individual flechette cavitation measured over 800% of the flechette diameter, averaging 0.580 inches. The flechette's supersonic cavitation ratio is proportionally equal to or greater than the cavitations of most handgun and buckshot projectiles in current use.
All flechette projectiles impacting the ballistic gel passed completely through the target block, no projectiles were stopped by the the tissue simulant. The average distance for the divergence of the flight path was between 3 and 4 inches of penetration and this include the begining of yaw for some flechettes. The divergence of flight path expands the area of potential trauma with each projectile having more than sufficent energy to pass through the 16 inches of ballistic gel. The flechette's divergence in flight path is superior to the limited divergence of buckshot projectiles which tend to follow a single path through a target.
M1A8 flechette shotgun ammunition fired off hand from a supported rest using a standard issue Mossberg M-590 shotgun with 20 inch barrel and cylinder bore choke. Target was 20 gauge steel sheet 48 x 48 inches with painted on standard U.S. military E-target sillouette and highlighted vital areas, per AFMAN 36-2227. Target range was 20 meters (21.87 yards/65.61 feet), with the aim point being the lower thoracic cavity highlight. Of the 95 projectiles illustrated 98% fully penitrated the steel target, 3 projectiles yawing greater than 5 degrees failed to penitrate.