Review: Tisas PX-5.7 FO

The idea that a faster-moving, lightweight projectile can do the same work as a heavier, slower-moving slug has been around for ages, and the math clearly supports it, even if some in the general public don’t. This, unfortunately, was the case when Fabrique Nationale introduced its first firearms chambered in 5.7×28 mm FN, a cartridge designed for the Personal Defense Weapon (PDW) role that promised some level of armor penetration without excessive recoil. And although the military/law-enforcement versions of the chambering made good on this pledge, 5.7×28 mm FN did meet its match in one barrier that it couldn’t break through: price.

The American market had a hard time accepting the high costs of the original firearms and their ammunition, religating the package to novelty status for the first 25 years of its existence. But renewed interest in the cartridge, and the guns that fire it, has led to the introduction of several new 5.7 mm pistol and carbine models during the past five years, some of which—like the Tisas PX-5.7 FO evaluated here—are offered at price points that fit into more shooters’ budgets.

Imported by SDS Imports, the PX-5.7 FO is an internal-hammer-fired semi-automatic pistol that feeds from a 20-round detachable box magazine. When a cartridge is fired, the recoil sends the barrel and slide rearward together, allowing the bullet to exit the muzzle and chamber pressure to drop to a safe level. After approximately 1/4″ of travel the two separate, allowing the fired cartridge to be extracted and ejected while the internal hammer is re-cocked. Once the slide finishes its rearward travel, the recoil spring returns it to battery, chambering a fresh cartridge and making the pistol ready to fire again.

The 5.7×28 mm FN is one of the softest-shooting centerfire cartridges on the market, so taming recoil doesn’t require an excessively heavy frame, and Tisas wisely chose lightweight polymer for this component. As the 5.7 mm cartridge and its magazines are considerably longer than other pistol cartridges, the manufacturer took several measures to ensure that the grip was not too bulky and cumbersome. Among these is a relieved area where it and the trigger guard intersect. This assures average-size hands have no trouble wrapping around the grip while allowing for a higher grasp relative to the bore axis to better manage recoil.

Mildly aggressive texturing is molded around the grip’s entirety to further aid in controlling the pistol and is met with a pair of panels bearing the same texture just above the trigger. These panels offer some grit for the support-side thumb as well as a tactile reference point for the trigger finger when the shooter isn’t actively firing the pistol. As for controls, the PX-5.7 offers a low-profile takedown lever up front and bilateral slide stops near where the thumb rests when assuming a firing grip. Below that is an oblong, reversible, push-button magazine release. The only active safety on the pistol is located inside the trigger bow, however, a passive firing-pin block is built into the slide to ensure it is drop-safe. A five-slot Picatinny rail is molded into the dustcover for an accessory.

The Tisas PX-5.7’s “FO” designation indicates its use of a green fiber-optic front sight; the optics-ready variant of the gun is called the “OR.” The rear sight is a solid black notch surrounded by well-defined serrations to help eliminate glare. It is dovetailed into the slide using a Glock-pattern cut, allowing the end user to drift it for adjustment or replace it with another sight. Aside from the sights, the only other notable feature on the slide are the aggressive cocking serrations found both fore and aft.

Ammunition choices for the 5.7 mm are becoming more plentiful, with at least five different manufacturers now offering one or more loads. For testing we selected three 40-grain options—Federal’s American Eagle, Hornady’s V-Max and Speer’s Gold Dot. Testing began with a bench-rested accuracy evaluation, with which all shooters were quite pleased.

By now, we’ve learned that we can expect more out of an import than we could in the past, and this pistol did not disappoint. Slow-fire work offers the best opportunity to feel the subtle nuances of a trigger, and most described it as long but smooth. Testers also remarked on the ease and comfort afforded by the flat, wide trigger bow. Breaking at a touch more than 5 lbs. puts it on the middle ground of pull weights, but overtravel is virtually nonexistent, adding to the overall accuracy.

The reset was a little long, though, as it required the trigger to return nearly completely to its forward position before it could be fired again. This slowed down rapid-fire testing but wasn’t a deal-breaker. Thanks to the pistol’s lack of muzzle rise, even less experienced shooters had no trouble re-acquiring the sights and getting a second shot downrange in a hurry.

We concluded our test after exhausting close to 200 rounds of ammunition—with the only stoppage to speak of occurring during the first magazine. We attributed this simple failure to feed to a firearm’s natural break-in period, as it could not be replicated again that day. The consensus was that this pistol would make a solid choice for anyone interested in the 5.7×28 mm FN who doesn’t want to break the bank. And since firearm production stimulates ammunition production, we hope the addition of another solid 5.7 mm option on the market helps further reduce the price of this interesting little cartridge.