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Paradigm Shift: PolyCase ARX Ammo

Paradigm Shift: PolyCase ARX Ammo

PolyCase Ammunition's cutting-edge, injection-molded, proprietary-composition ARX bullets will have you rethinking how a personal-defense bullet is supposed to perform.

Advanced Rotation eXtreme: That's what PolyCase ARX stands for. These innovative bullets have less carry weight, higher velocity, flatter trajectory, less recoil and less potential for ricochets. The bullets help eliminate corrosion, and they are competitively priced. Because they are engineered primarily for personal protection, terminal ballistic performance is highly effective and consistently predictable. More about the performance in a few minutes.

The firm experimented with various formulae for the PolyCase ARX until a proprietary mixture of copper powder metal, glass-fiber reinforced nylon made by PolyOne, and other unnamed contents was finalized.

While listening to detailed technical presentations at PolyCase Ammunition in Savannah, Ga., and participating in extensive shooting sessions, I was extremely impressed with the technology involved with producing these unique bullets.


But I came to realize there was a problem. The problem wasn't with the bullet's unique design, composition, or performance. The problem was I didn't know how I was going to convey just how well it works.


The "before" and "after" photos of conventional jacketed hollowpoint bullets compared to Polycase ARX bullets clearly demonstrated my dilemma. Other than the rifling striations, there's no indication the PolyCase ARX has done anything.

In fact, recovered PolyCase ARX bullets show that the design does not expand. It penetrates all soft material and tissue like any conventional FMJ bullet. But seeing the dramatic results when an ARX bullet strikes a gelatin block, a melon, and a jug of water forced me to rethink everything I thought I knew about how a personal-defense bullet is supposed to perform.

PolyCase Ammunition is a recent startup in the civilian munitions market. Headed up by retired Army Ranger Lt. Col. Paul Lemke and Juan Carlos Marin, its first product was "single-use" .380 ACP ammo that used injection-molded plastic cases topped with conventional cup-and-core JHP bullets. A few months after launching that ammunition, the company came up with its idea of making composite copper-polymer (Cu/P) bullets.

polycase-STMP-151000-PLY-02-arxThe firm experimented with various formulae until a proprietary mixture of copper powder metal, glass-fiber reinforced nylon made by PolyOne, and other unnamed contents was finalized. In addition to the usual roundnose bullets, PolyCase engineers, along with Steve Johnson, who is formerly of Hornady, developed the unique ARX design that has three flutes. I think of them as power vanes.


The Cu/P PolyCase ARX bullets are approximately 35 percent lighter in weight than typical jacketed lead-core bullets, so they can be fired at higher velocities. Kinetic energy sacrificed by the reduced bullet weight is almost fully reclaimed by the enhanced velocity. Another important plus is that a Cu/P round generates appreciably less recoil, meaning it's easier on the gun and the shooter.

Cu/P bullets are not frangible; however, unlike a malleable lead-core bullet, they readily break up when they strike a hard surface; consequently, they don't ricochet back at the shooter. And because there's no lead, they're "friendlier" to the environment.

As this recovered .45 ACP bullet shows, PolyCase's unique injection-molded, proprietary-composition ARX bullets do not expand when fired into ballistic gelatin.


PolyCase ARX rounds are formed through a precision injection-molding process that involves an 80-ton press assembly dropping a charge of predried granules from a gravity-fed hopper and stroking a piston to force the material mixture into a precision-machined, water-cooled mold. The end product is a copper-polymer matrix "tree" comprising a stem and four branches with four fully formed projectiles attached to the end of each branch.

The "tree" with 16 still-warm composite bullets attached falls onto a conveyor belt, and an operator removes the stems and branches from the collection container and boxes the bullets for transfer to the ammunition-loading facility. Almost all of the "scrap" is reprocessed and mixed with virgin Cu/P material to press into more bullets.

The fully automated process is closely monitored by multiple sensors that record pressure levels and mold sequencing. Any deviation from preset limits causes an immediate shutdown, and the problem is identified and resolved before production resumes. Sample bullets are routinely spot-checked to ensure the strict quality requirements are met and maintained.

The 74-grain 9mm PolyCase ARX penetrated 12 to 14 inches in gelatin and created a wound cavity of 3 inches.

How the ARX Works

As I said earlier, the PolyCase ARX bullet does not expand because it's designed to rotate through tissue and cause devastating shock through fluid dynamics and lateral force. Operating like a hydrodynamic ram, the bullet compresses the fluid-filled tissue ahead of it and creates a temporary cavity as it dumps rotational energy into the tissue.

The bullet's flutes cause the fluid in the target's tissue to be accelerated and displaced, causing the wound cavity to increase. As the fluid's velocity across the bullet's flutes increases, shock waves are produced. There is an illustration of how this unique bullet works on PolyCase's website, and it helps explain the PolyCase ARX's effect on the fluid-filled tissue.

STMP-arx-151000-polycase-PLY-07During my visit to the PolyCase facilities, we fired hundreds of rounds downrange at paper targets, steel targets, and other targets of opportunity, including melons, oranges, and water jugs, and we also shot 9mm and .45 ACP PolyCase ARX bullets into gelatin blocks with and without denim/leather barriers at a range of 10 feet.

The 9mm bullets (at 1,400 fps) penetrated 12 to 14 inches and caused an initial cavity of up to 3 inches. The .45 ACP bullets (at 1,150 fps) penetrated several inches more and created an even larger cavity. By the way, the PolyCase ARX fed just like a roundnose bullet; the flutes had no negative effect on feeding whatsoever.

One round of .45 ACP ARX was fired at soft body armor backed by gelatin. It penetrated the first layer of Kevlar and then the nose flutes shattered. The bullet shank remained intact but was fractured into three, roughly equal segments. It was obvious that if a human had been wearing the body armor, he would have been subjected to significant blunt force trauma.

I haven't seen what the PolyCase ARX does to a human, but I have seen what it did to a large hog. Both eyes were pushed out, and the head was drastically flattened. The results were devastating.

STMP-151000-polycase-PLY-arx-08Range Results

Returning home, I outlined a test plan to demonstrate the PolyCase ARX's performance at my local range. I decided to fire multiple 10-shot groups of .380 ACP, 9mm, and .45 ACP PolyCase Inceptor ammunition and other brands of ammo and tabulate the velocity and accuracy results. I would also include calculated values of the muzzle energy and "free recoil" energy.

I tested the 9mm and .45 ACP factory loads in both compact and full-size pistols. The recoil energy formula, taken from Lyman's reloading manual, requires using the propellant charge weight in the calculations. I reviewed the Lyman manual to estimate an average value for the jacketed-bullet factory loads, and I used actual charge weights for the various PolyCase rounds.

When fired at body armor, the 114-grain .45 PolyCase ARX's flutes shattered and the base fractured into three pieces, but it would have caused considerable blunt force trauma.

As you can see, velocities for the PolyCase ARX were substantially greater than the conventional factory loads. I expected that. In most cases, the muzzle energies were higher, and the accuracy results were comparable.

In my opinion, the main point of interest is the recoil figures. As the chart indicates, each gun's kick was 25 percent to 35 percent less with the PolyCase ammo. I could definitely feel the difference when doing the shooting. Taming recoil without sacrificing ballistic performance will be welcomed by shooters using compact, lightweight handguns.

So, to review, the PolyCase ammunition loaded with ARX bullets has less carry weight, higher velocity, higher energy (in most instances), and less recoil. Its terminal ballistics are incredibly effective. It's available through suppliers like Cabela's at a list price of $21 per box of 20 rounds, so it is competitively priced.

All of that means that my testing of the ammo proves that PolyCase's claims are accurate. ARX bullets are currently available in PolyCase's brass-case Inceptor line of ammo in .380 ACP, 9mm Luger, .40 S&W, and .45 ACP; .38 Special and .357 Sig are said to be coming very soon.polycase-arx-ballistics

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