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Review: Palmetto State Armory 5.7 Rock RK1 Pistol

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In the spring of 2022, Palmetto State Armory (PSA) released the 5.7 Rock, which continues to be the most affordably priced semi-automatic pistol chambered in FN 5.7x28mm here in the United States.

After FN Herstal developed the 5.7×28 mm FN cartridge in 1990 for NATO, the only handgun available to fire it was the FN Five-seveN. This particular semi-automatic pistol is currently selling for around $1,400. It wasn’t until December 2019 that the next commercial competitor in the 5.7×28 mm category arrived in the form of the Ruger-5.7, which currently sports a suggested retail price of $899. When the standard version of the PSA 5.7 made its debut, the suggested price was $500, or close to one-third the price of a factory-fresh Five-seveN.

palmetto state armory 5.7 rock pistol in nylon case on logThis pistol ships in a configurable zippered soft case with two magazines.

In 2023, the Smith & Wesson M&P 5.7 pistol arrived on the scene and is listed for $699. During the same time frame, the PSA 5.7 Rock lineup grew to include optics-ready models and the RK1 models that ship with threaded barrels, vented slides and Cerakote finish options. With the RK1 model prices topping out at $600, even the most dressed up 5.7 Rock pistol still costs at least $100 less than the nearest competitor.

When delving into the PSA catalog to find a 5.7 Rock model for evaluation, it took a minute to sort through the options. With various slide colors, frame colors, barrel colors, flush fit barrels, threaded barrels and slides with or without RK1 venting, there were more than 60 optics-ready pistol configurations and packages to choose from at the time (not including the no-optics models).

Palmetto State Armory 5.7 Rock pistol left side two-tone stainless steel slide black polymer frame shown on wood logOptics-ready 5.7 pistols are available in a variety of configurations, including the 2-tone threaded barrel model shown here.

In the end, I went with the model I liked best. This review takes a closer look at the optics-ready two-tone Model RK01-51655140298. Its solid, no-vents silver 416 stainless steel slide features front and rear cocking serrations. The 5.2″ long carbon steel barrel is treated with a matte black finish that matches that of the black polymer frame and its appointments.

The muzzle of the barrel is threaded at 1/2×28 TPI to support popular barrel-mounted accessories. This configuration is topped off with a set of black metallic suppressor-height sights consisting of a narrow blade up front and a dovetailed square-notch sight at the rear. The sight system used is Glock-compatible, which makes it easy to trade the sights out for other configurations. I’ve always liked silver/black two-tone pistols but the long, slim profile of the solid 5.7 slide looks particularly sharp.

PSA Rock 5.7 pistol controls shown on logThe 5.7 Rock has an integral trigger safety and a reversible magazine release button.

The full-size 5.7 Rock RK1 is a striker-fired, polymer-frame pistol that employs a delayed-blowback action design. The barrel remains locked in place when firing to contribute to improved mechanical accuracy. Removing the slide from the frame reveals a relatively stout one-piece polymer guide rod featuring a spring loaded plunger and a single captured flat-wire recoil spring.

The full-size frame’s dust cover is long enough for a 2.5″ three-slot accessory rail that will accommodate a variety of light and laser sight modules. The front edge of the oversized trigger guard is canted with a small ledge at its base to serve as a finger rest. The external controls consist of a takedown release located inside of the trigger guard, a left-side slide stop lever and a reversible metallic magazine release button.

PSA 5.7 barrels shown with pistol on logPSA offer addition flush fit and threaded barrel options starting at $90.

The gently curved polymer trigger is fitted with an integral blade safety. The company describes the trigger as single-action. It did exhibit a hint of take-up before breaking cleanly with 4 lbs., 12 ozs. of trigger pull. The trigger felt lighter than this due to a short arc of travel that is only about 0.25″, and it exhibited a distinctive trigger reset. In short, the trigger feels more like a tuned competition model than that of an off-the-rack striker pistol.

The grip features panels of effective but non-abrasive texturing on all four sides. The trigger guard is undercut where it meets the front strap with just a hint of a single finger groove just below. The top of the backstrap features a lip that takes the place of an extended beavertail without making this relatively long gun even longer.

psa 5.7 rock magazines and baseplates shown on logThis pistol arrived with two 23-round magazines and mounting plates for optics with RMR and Docter footprints.

The 5.7×28 mm FN cartridge is about 0.42″ longer than the 9×19 mm Parabellum. This requires a greater front-to-back grip distance than many folks are used to working with. PSA did an admirable job of shaping the contours of the 5.7 Rock grip frame to make it comfortable to work with, even for folks with somewhat smaller hands like mine.

This pistol uses double-stack and double-feed magazines. The bottle-neck shape of the 5.7×28 mm FN cartridge allows for the double-feed configuration, meaning, rounds are pressed straight down just like loading an AR-15 magazine. PSA’s blued steel double-stack magazines can hold up to 23 rounds. This allows 5.7 Rock series pistols to carry one more shot than the Smith & Wesson and three more than the FN and Ruger models.

Palmetto State Armory 5.7 Rock Rk1 pistol disassembled parts shown on logLike other polymer framed striker pistols the 5.7 Rock breaks down quickly and easily for routine cleaning.

With an overall length of 8.88″, thanks to the extended threaded barrel, one might expect the 5.7 Rock to have a hefty feel. But this is not the case. The gun I worked with weighed in at 25.7 ozs. with an empty magazine. The slide is only 1″ wide, which contributes to a handy, well-balanced feel. The fit and finish proved to be top-notch throughout, the slide is relatively easy to cycle manually and the magazine springs were nice and tight.

PSA 5.7 Rock RK1 pistol shown with Swampfox red-dot opticThe RMR-size Swampfox optic provided a wide sight picture useful for distances of 25 yards or more.

The slide’s optics cut out is sized for smaller Shield RMS-footprint optics to be attached without the need for a mounting plate. The pistol shipped with a slide filler plate and two mounting plates for RMR and Docter size optics. For this evaluation, the pistol was fitted with an RMR footprint Swampfox Justice II 6-m.o.a. red dot with a generously sized 30-mm ruby-coated lens, aluminum housing, ten brightness levels and up to 50,000 hours of runtime using one CR1632 battery. Although the pistol cycled reliably with the larger Justice II, the optic’s extended lens rim took a beating on the right side from the energetically ejected cartridge cases. This is a good optic that I plan to work with again, but a smaller optic would clearly be a better fit for this particular handgun.

psa 5.7 rock rk1 range restThe 5.7 Rock’s felt recoil was similar to that of .22 Mag. semi-automatic pistols the author has tested.

At the shooting range, the 5.7 Rock pistol, with a total of four factory magazines, proved to be utterly reliable with most of the ammunition tested. I had hoped to do some shooting with a subsonic load through a Silencer Central Banish 22 sound suppressor, which is rated for use with 5.7×28 mm FN. However, the subsonic load caused too many feeding issues to justify continued testing. Of the four typical velocity loads, with 35-grain to 40-grain bullets, there was not a single malfunction of any kind using either the factory installed 5.2″ barrel or a second 4.7″ flush-fit barrel I had on hand.

5.7x28 mm FN ammunition federal hornady speerThankfully FN 5.7×28 mm ammunition is not as expensive as it used to be.

As for accuracy, I had no complaints there either. The combination of the single-action trigger, red-dot optic, comfortably hand-filling grip and the softer shooting characteristics of the 5.7×28 mm FN cartridge contributed to bench rested five-shot groups that hovered around 2″ to 2.5″ in size at 25 yards. Here are the range results fired with Federal American Eagle, Hornady Black and Speer Gold Dot loads using a Garmin Xero C1 Pro chronograph to measure bullet velocities:

5.7x28 mm testing ballistics accuracy graph table specifications velocity psa rock 5.7 pistol test

Pistols chambered in 5.7×28 mm FN have been gaining traction with American semi-automatic fans over the last few years. Working with this Palmetto State Armory optics-ready 5.7 Rock pistol has been the first opportunity for me to test drive this gun and ammunition combination for myself. After this range test, I can see what the hubbub is all about.

Speer Gold Dot ammunition box with target triangle bullet hole group accuracy testingSpeer Gold Dot ammunition yielded the best single five-shot group of 1.27”.

The 5.7 Rock itself is a well-made and properly thought out pistol at a price that’s hard to beat. It proved to be reliable, accurate and enjoyable to shoot. And with 5.7×28 mm FN ammunition prices having shifted from $1 a pop down to around $0.50 per round, or .45 ACP and .40 S&W territory, its modest levels of felt recoil can be enjoyed without breaking the bank.

At the 2024 SHOT Show in Las Vegas, NV, PSA trotted out a collection of prototypes for customers to vote on. Among them was a compact-size version of the 5.7 Rock. After the positive results of this range test, I’m eager to see that configuration in action as well.

Palmetto State Armory West Columbia, SC stamping on gun frame two-tone stainless steel slide black ploymer

PSA 5.7 Rock RK1 Specifications
Manufacturer: Palmetto State Armory
Action Type: delayed-blowback-operated, semi-automatic, centerfire pistol
Chambering: 5.7×28 mm FN
Frame: black polymer
Slide: 416 stainless steel
Barrel: 5.2″ carbon steel, QPQ finish; 1/2×28 TPI
Rifling: six-groove, 1:9″ RH-twist
Finish: two-tone
Magazine: 23-round detachable box
Sights: Glock compatible; blade front, dovetailed square-notch rear
Trigger: single-action, 4-lb., 12-oz. pull
Overall Length: 8.86″
Height: 5.75”
Width: 1” slide; 1.25″ grip
Weight: 25.7 ozs. (with empty 23-round magazine)
Accessories: owner’s manual, zippered soft case, two magazines, cable lock
MSRP: $560

Article by B. GIL HORMAN

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