Building on the success of the popular Critical Defense ammunition, Hornady took the concept one step further on the road to developing the illusive “magic bullet.” The existing round had proven very successful at meeting the FBI performance standard delivering favorable expansion and penetration in calibrated ballistic gelatin even after passing through heavy clothing including high-loft fabric and leather. Reasoning law enforcement personnel are very likely to become involved in engagements where a variety of barriers are present, Dave Emary, the Hornady engineer who developed Critical Defense, went to work on a round delivering optimum performance against such common barrier material as plywood, steel, wallboard and windshield glass.
A Hornady shooter fires Critical Duty rounds through barrier material, cloth and into ballistic gelatin. Note the camera mounted on the Glock.
Critical Duty ammunition features the FlexLock bullet. The notes relate to the BB calibration of the gelatin block (above). The bullet’s inter-lock (below) prevents jacket separation and the crimp groove elimimnates bullet setback.
According to the FBI protocol, two pieces of 20-gauge galvanized steel is equivalent to the weakest portion of a car door. Two pieces of 1/2-inch gypsum board is a fair proxy for internal residential and business structures, 3/4-inch plywood is also a common structural material and laminated automobile windshield glass is standard for the industry. The hoped-for outcome is the projectile will penetrate these barriers, penetrate 12 to 18 inches in ballistic gelatin and expand to 1-1/2 caliber in the process. In order to perform consistently, the bullet must be extremely well stabilized to eliminate yaw upon and after impact, resist deformation and plugging upon contact with the initial barrier and still expand in the medium.
Key elements in the emergent Critical Duty rounds are embodied in the FlexLock bullet that came out of Emary’s research. Flex Tip technology maintains the integrity of the bullet and aids in expansion. An interlock rather than core-bonded jacket allows use of a tough antimony/lead alloy core promoting penetration, expansion and maximized weight retention. Initial rounds include a 9x19mm load with 135-grain projectile at standard and +P pressures.
Emary had warned us to be wary of any manufacturer claims of absolute 100 percent perfection adding that windshield glass would occasionally defeat the new bullets. Nevertheless, on this occasion, the Critical Duty rounds, shot through the various barrier materials did, in fact, achieve an amazing consistency in expansion and penetration. All met the FBI performance expectations.
I requested a sampling of the 9mm load to test in my own pistols. These included the standard pressure load from the Grand Island visit and a box of the +P loading of the same bullet. The Critical Duty rounds are in nickel-plated brass to resist corrosion and facilitate low-light chamber checks. The rounds are sealed at the primer and case mouth. Low flash powders are optimized for each load and do produce narrow extreme spreads over the chronograph. I shot 5-round groups from 25 yards through my SIG 210 Legend and a loaner Kahr CM9 with 3-inch barrel. The FBI standard is rather fussy about accuracy, deploring groups that exceed 1.25 inches—though probably from a machine rest. The SIG clustered the standard-pressure load in 1.2 inches and the +P in 1.4 from my casual setup, clocking 965 fps and 1,140 fps respectively. The Kahr Arms pocket pistol put the standard loading at 891 fps into a 3.8-inch group and the +P at 1,023 fps into a 3.2-inch group. I did not have enough ammunition on hand to do expansion tests with the smaller pistol, but the FlexLock bullet is promoted as performing across a wide range of velocities, providing hope decent expansion and penetration will extend to the smallest of 9mm concealment arms.
A couple of years ago at the Texas Department of Public Safety Academy, one of the instructors remarked, “We are on the verge of getting the ‘Magic Bullet.’” While his enthusiasm was directed toward the industry-wide state of bullet technology, the Hornady Critical Duty offerings surely bring us a step closer to that goal.
By Mike Cumpston
Hornady Manufacturing Company
3625 West Old Potash Hwy
Grand Island, NE 68803