Foregoing bonding required innovative thinking to ensure integrity against the prescribed barriers while also achieving proper penetration, which the FBI TEP describes as follows: “It is desirable that the service projectile consistently penetrate an average of 12" to 18" throughout gelatin tests, with no shot less than 12" and no shot greater than 18" … .” Emary returned to Hornady’s roots for the solution; he combined a larger-than-normal mechanical locking ring—InterLock—with a high-antimony lead core, which is preferable in applications calling for high-retained weight. The latter could not be utilized if bonding was to take place, thereby reducing control over bullet deformation and expansion for optimal performance in gelatin. A sectioned FlexLock reveals an unusual, disproportionately heavy midsection with the lead-alloy core in a quasi-arrowhead/hour glass shape; it’s easy to understand how jacket-core slippage is prevented.

Unlike Critical Defense’s FTXs, Critical Duty’s FlexLock bullets are noticeably heavy-for-caliber. For example, in the 9 mm Luger and 9 mm Luger +P loads a 135-gr. version is used, and in .40 S&W the projectile weighs 175 grs. (which meets the Bureau’s call for a .40-cal. projectile “no less than 155 grs, nor exceed[ing] 200 grs.”). “Heavy for caliber is a function of the barriers that are expected to be defeated and yet have the bullet still achieve a minimum of 12" of gelatin penetration,” said Emary. “Lightweight bullets do not have the momentum to defeat barriers and achieve the required penetration depth.” Because of the bullet weights and the standard propellants used, recoil is more noticeable than with Critical Defense; however, it is by no means intolerable.

Hornady’s flexible, red elastomeric tip material is used on the FlexLock. Whereas FTX tip’s primary duty was to prevent cavity blockage, with secondary service aiding uniform expansion, the FlexLock does the aforementioned, as well as ensuring the cavity doesn’t collapse in upon impacting steel. “This is where the FlexTip material shines, “ Emary said. “The combination of the jacket taper design and FlexTip material prevents the nose from collapsing and forces the nose of the bullet to deform around the tip. You end up with a bullet looking like a toadstool. In essence, the bullet is ‘pre-expanded’ by the steel and performs just like a normal bullet in gelatin.” Reportedly, typical expansion across-the-board is 1.487 times caliber in 9 mm Luger, 1.617 in 9 mm Luger +P and 1.415 in .40 S&W. Average weight retention percentages, excluding the glass tests, are 99.8, 99.4 and 98.8, respectively.

Critical Duty also borrows from Critical Defense in its use of nickel-plated cases and clean-burning propellants with flash deterrents added. The former enables easier chamber checks in low-light conditions, as well as enhances feeding, extraction and corrosion-resistance, while low-flash propellants preserve vision at night. Since Critical Duty was developed around full-size handguns, standard propellants—unlike Critical Defense’s progressive type—were utilized.

Put To the Test
Earning an FBI contract for “service” ammunition requires fulfilling the numerous conditions outlined in the TEP. Of the “Phase 1” requirements, though, the most difficult for manufacturers to meet are likely the penetration tests, with each simulating a real-world threat. It was for this very reason that I traveled to Hornady’s Grand Island, Neb., facility last fall—to witness Critical Duty in action. All testing was conducted using a Glock 17 (9 mm Luger) firing the 135-gr. +P load.

Of the eight tests, arguably the most difficult are “steel” and “auto glass.” It was here, respectively, that the evaluation began. For the steel test, two sheets of hot-rolled automotive sheet metal with a galvanized finish are spaced 3" apart, a calibrated gelatin block is draped with light clothing and placed 18" behind the metal, and the shot is taken from 10 ft. Propelled at 1165 f.p.s., the FlexLock easily pierced the steel layers and heavy clothing, and it attained a depth of approximately 13" in the ballistic gelatin. The recovered bullet weighed 133.1 grs. and measured 0.501" at its widest. As Emary had stated, it indeed resembled a toadstool. As for the glass test (described previously), which Emary equated to shooting through 1/4" of concrete, the bullet retained 67.1 percent of its original weight and expanded to 0.443", yet it still penetrated about 13¾" of gelatin. A second glass test was unnecessary.

Subsequent tests revealed FlexLock’s performance against bare gelatin, heavy clothing, plywood and wallboard, respectively. Against bare gelatin, which effectively represents a shirtless subject, from 10 ft. the FlexLock penetrated about 14¼" to 14½" of gelatin, where it was found to weigh 134.2 grs. and expanded to 0.544". Versus “heavy clothing” at 10 ft., the bullet expanded to 0.500", weighed 133.9 grs. and penetrated 15¾" to 16" of gelatin.

The final barrier tests conducted were against plywood and wallboard. The former consisted of one piece of 3/4" AA fir plywood, the latter two pieces of 1/2" gypsum board spaced 3½" apart, and both with a gelatin block with light clothing placed 18" behind and shot from 10 ft. After boring through plywood, the FlexLock attained a depth of about 16", where it weighed 134.0 grs. and expanded to 0.504". Against wallboard, the bullet penetrated nearly 13¾" of gelatin, weighed 134.3 grs. and measured 0.571" at its widest.

Regardless of the barrier it encountered, the FlexLock caused the most damage between approximately 1" and 6" of penetration; considering the chest-to-back depth of the human body, that’s about ideal. It’s comforting to know that, even after engaging barriers, the FlexLock will still deliver.

With barrier testing complete, I tested Critical Duty for accuracy and consistency. From a 4" Springfield Armory XD pistol outfitted with a LaserMax LMS-Micro atop a Hyskore Utility Bag rest. The 135-gr. 9 mm Luger load averaged an excellent 2.08" for five consecutive, five-shot groups at 25 yds. Equally impressive was the load’s consistency: through an Oehler Model 36 chronograph, at 15 ft. the load averaged 1001 f.p.s.—Hornady’s number is 1015 f.p.s.—and the standard deviation was 10.

Critical Duty is available only in 9 mm Luger and 9 mm Luger +P (135 gr.) and .40 S&W (175 gr.).

Hornady’s website prices it at $28.75 per 25 (9 mm Luger and +P) or 20 (.40 S&W). Cabela’s prices it at $21.99 for 9 mm Luger, and $22.99 for 9 mm Luger +P and .40 S&W. Currently .45 ACP is being designed, and .357 SIG and 10 mm are also likely candidates.

Given what I’ve observed, Critical Duty is a remarkable product that delivers as touted. It is little wonder why states such as Kansas, South Carolina, Idaho, Nevada and Utah have contracts for it, thereby enabling all their departments and agencies to order the ammunition. Of the few “absolutes” in life, count Critical Duty’s performance among them.

Test Results:

Bare Gelatin Test 9 mm Luger 135-gr. +P

Auto Glass Test 9 mm Luger 135-gr. +P

Heavy Clothing Test 9 mm Luger 135-gr. +P

Plywood Test 9 mm Luger 135-gr. +P

Drywall Test 9 mm Luger 135-gr. +P

Sheet Metal Test 9 mm Luger 135-gr. +P