Precision tactical rifles dominate the market, leaving shotguns, the proverbial blunt instruments, marginalized as low tech. Yet close-quarters battle often requires more versatility than a rifle or carbine can provide. Two examples come to mind when considering the advantages of using a shotgun for CQB situations. While a rifle or carbine will kill hostiles, full-metal-jacket (FMJ) projectiles can overpenetrate and kill or wound noncombatants. Also, breaching a door usually is best done using a 12-gauge shotgun with a serrated standoff/breaching muzzle device.

One such breaching device is the Dragon, made by Aimpro Tactical. Located in Golden, Colorado, the company has been threading Mossberg 590A1 barrels for some time to enhance the shotgun’s performance, and it recently introduced the Dragon to exploit the flexibility of this feature. Like a choke, the serrated device screws into the muzzle. The Dragon also provides modest muzzle-brake characteristics, which may account for some of the shotgun’s increased controllability. The ability to use chokes and breaching devices increases a shotgun’s versatility.

But Aimpro Tactical can do more than just make muzzle devices. The company improves factory firearms using expert gunsmithing techniques and by adding performance-enhancing upgrades to proven systems. It’s best known for its utilitarian performance work on the venerable Mossberg shotgun platform. In fact, Aimpro Tactical’s founder, Mike Shain, has been optimizing the potential of pump-action and semi-auto Mossbergs for more than 10 years. The company is also the only official Mossberg Law Enforcement Warranty and Repair Services facility.

Developing new products and finding engineering improvements motivates Shain to build guns like the Ultimate 590A1. The gun started as Aimpro Tactical’s response to repeated requests from its elite law enforcement customers for a true co-witness pump-action shotgun, meaning it would utilize the immensely popular red-dot and holographic sights that have become commonplace on long guns paired with a set of backup iron sights. This combination is pretty rare on a traditional shotgun, but the Ultimate is anything but traditional.

Beyond The Box
A base mil-spec Mossberg 590A1 platform is hardly recognizable after Aimpro Tactical’s transformation. Starting with a plain-Jane, 18.5-inch, heavy-walled-barrel model, Aimpro disassembles and strips the gun. Each component goes through a parts washer for degreasing. From there, a 3-inch length of mil-spec Picatinny rail—machined from solid bar stock with the proper elevation for the co-witness sight package—is brazed onto the barrel using a custom-made appliance to ensure precise alignment of the front and rear rails.

After refinishing the receiver and barrel with Aimpro’s proprietary ExtremeCoat finish, the shotgun undergoes the signature Aimpro performance shop treatment: a hand-polished action job, forcing-cone reprofiling and a complete hone and polish of the chamber and the bore all the way to the muzzle. The shotgun is assembled, function checked and test-fired to assure its absolute reliability. The result is a smooth action and excellent downrange performance with slugs and buckshot—something Aimpro has developed a reputation for within tactical shotgun circles.

Each shotgun receives the best mission-specific accessories available: a Mesa Tactical Enidine recoil-reducing adjustable stock and a Falcon Industries Ergo tri-rail forend with low-profile rail covers. A SOG Graphite vertical foregrip, a Command Arms Accessories cheekpiece, an Aimpro heatshield and a LimbSaver M4 recoil pad round out the aftermarket gear. Magna-porting the barrel is also an Aimpro option. Valuable additions would be a white light mounted on the full-length rail forend, plus a sling. According to Shain, “Most of our Ultimate customers want to select their own light setup and choose a single- or three-point tactical sling once they’ve had a chance to handle the gun and determine what’s optimal for their application.”

An extra-long receiver rail designed to match up with the proprietary front-sight rail enables the co-witness system to accept any standard-elevation co-witness sight package. This particular build was fitted with an Aimpoint CompM4 red dot and a pair of polymer, mil-spec ARMS #71L folding backup sights. Aimpro Tactical’s Ultimate M590A1 is available in several finishes, including OD green, Flat Dark Earth and gunmetal grey.

Going Downrange
To evaluate the inherent accuracy of Aimpro’s Ultimate 590A1 shotgun, I fired it from a supported position with a warm barrel using standard IPSC targets at a distance of 50 feet. Elevation was 8,450 feet with no measurable wind.

My targets attest to the gun’s substantial accuracy, and photos of the gun show its cosmetic appeal. But they cannot convey the action’s smoothness and remarkable lack of perceived recoil. Muzzle rise was negligible, and it was quick and easy to find a proper cheekweld thanks to the elevated cheekpiece on the buttstock.
The pistol grip and vertical foregrip arrangement had a natural feel. Cycling the slide was a bit different than with a typical pump action, but it was effortless thanks to the Aimpro action work, the grippy feel of the SOG Graphite foregrip and the Hogue M4 pistol grip that comes standard with the Mesa Tactical stock adapter. The gun functioned flawlessly throughout testing. It’s a high-speed, low-drag tactical tool.

Editor’s Note: N.E. MacDougald is a Vietnam veteran and former Soldier of Fortune staffer. He recently wrote a book under the SOF banner for Skyhorse Publishing ( titled Soldier of Fortune Guide to Surviving the Apocalypse: The Ultimate Source for Protecting Your Family Against Societal Collapse.

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