Gunner Quinn
The FN 5.7×28 mm FN cartridge has been enjoying a resurgence in popularity rarely seen with semi-automatic cartridges that did not catch the eye of the shooting public when they were initially launched. This is due in no small part to the release of pistol models with which cost less than the first pistol made for this round, the FN Five-SeveN. The models available these days include the Ruger-57, the Palmetto State Armory 5.7 Rock series and the Smith & Wesson M&P 5.7. As we look across these options, they share one notable feature in common—they are all full-size pistols. Although each of them is relatively slim and light weight, none of them are configured with concealed carry in mind.
This year, Palmetto State Armory (PSA) addressed the absence of daily-carry pistols chambered for 5.7×28 mm FN with the release of the new 5.7 Rock Compact series. And like many other compacts, it’s based on the duty-size model only with a slide assembly and grip frame that have been trimmed down slightly. In this case, the barrel has been cut down from 4.7″ to 4.3″ and the grip length has been cropped by 0.2″, which in turn has reduced the flush-fit magazine’s ammunition capacity from 23 rounds to 21 rounds. This pistol will accept the 23-round magazines, but they protrude from the grip. Color options currently include all black (shown), flat dark earth, olive drab or gray finishes applied to the slide and grip frame.
Like the full-size 5.7 Rock RK1 that I worked with previously, the Compact is a striker-fired, polymer-frame pistol that has a delayed-blowback action that locks the barrel in place when firing, leading to improved accuracy potential. The solid 416 stainless steel slide features front and rear cocking serrations along with a matte-black finish. The relatively tall suppressor-height sights found on the RK1 have been replaced with a metallic low-profile, three-dot sight set. These sights are Glock-compatible, which allows for a variety of sight upgrades, if desired.
The optics-ready slide arrived without any accessories mounted into the slide cut. Inside the soft zippered case, along with the two magazines and cable lock, was a plastic pouch containing two sets of screws for the provided slide filler plate and the two mounting plates for RMR and Docter-size optics. The slide’s cutout is sized for smaller Shield or Holosun K optics to be attached without a mounting plate.
For this evaluation, the pistol was topped off with a Holosun K-size SCS-Carry optic. It features an enclosed 7075-T6 aluminum housing, a green 2-m.o.a. dot ringed by a 32-m.o.a. circle and a singular control button for the brightness and reticle settings. A top-mounted solar panel recharges the built-in 20,000-hour battery for a suggested retail price of $470.
The 4.3″ fluted barrel is supported by a dual-spring guide-rod assembly that captures a pair of nested round-wire recoil springs. The 2.4″ long dustcover of the polymer frame sports a molded-in two-slot accessory rail for mounting lights and laser sights. The angled and flattened front edge of the generously sized trigger guard is shaped to serve as a finger rest. The curved polymer trigger is smooth faced and fitted with an integral blade safety. The trigger pull is better than many striker-fired pistols with a smooth takeup, a distinctive stop before the trigger break and a short distance traveled after the trigger breaks at 4 lbs., 8 ozs.
The remaining external controls include a pull-down takedown release located inside of the trigger guard, a left-side slide-stop lever and a reversible metallic magazine release button. The grip is treated on all sides with a light but effective texturing. The frontstrap features a single finger groove while the top of the backstrap sports a slight, rounded beavertail for a more comfortable fit with the web of the shooting hand’s thumb. The double-stack magazines are made of blued steel with followers and flat baseplates molded from black polymer.
Due to the positive shooting experiences and results I had with the RK1 version of this platform, I was looking forward to some range time with the Compact. Like its predecessor, this pistol operated reliably with all of the standard pressure ammunition tested. The clean single-action trigger; green-dot optic; the comfortable grip; and modest levels of recoil made for an enjoyable session, which was made even better with the absence of any pistol, ammunition or magazine related malfunctions using the two, factory flush-fit, 21-round magazines.
The standard-size 5.7 Rock pistol’s are available with either 5.2″ long threaded barrels or 4.7″ flush-fit barrels. The flush-fit version was already the shortest commercial option available. The FN, Ruger and Smith & Wesson offerings sport barrel lengths of 4.80″, 4.94″ and 5.00″ respectively. This makes the 5.7 Rock Compact’s 4.3″ barrel the shortest yet. Knowing that the 5.7×28 mm FN cartridge relies on projectile velocity in order for its lightweight bullets to expand properly, I was curious to see how this particular gun would perform.
I went back through my notes from the evaluation of the 5.2″-barrelled version of the 5.7 Rock RK1 pistol. Using loads topped with 40-grain bullets, the muzzle velocities were between 1,668 and 1,902 f.p.s. producing muzzle energy levels of 247 and 321 ft.-lbs. The accuracy results were quite satisfying, with an average extreme spread of just 1.87″.
Generally speaking, if a bench-rested pistol is punching out 3″ to 3.5″ five-shot groups at 25 yards using iron sights, or about half an inch less with an optic mounted to the slide, then I would say that the gun, ammunition and the guy pulling the trigger are operating properly. This pistol’s sub 2″ groups in most cases was a good indicator that the gun was out-shooting the shooter.
For the Compact model, the formal accuracy testing once again consisted of five, five-shot groups fired at 25 yards from a bench rest using the Holosun optic. Two of the loads were the same as the previous test, including Federal’s American Eagle 40-grain full-metal jacket practice load and Speer’s Personal Protection 40-grain Gold Dot hollow point, which is a popular option for self defense. The third load, Fiocchi USA’s Hyperformance Defense 40-grain polymer-tipped hollow point is another defensive option I’ve wanted to work with.
How much of a difference did the 4.3″ barrel make? To summarize, the 40-grain bullet velocities were between 1,609 and 1,671 f.p.s. for muzzle energy levels of 230 and 248 ft.-lbs. As for accuracy, the average extreme spread expanded by nearly an inch at 2.68″. This level of accuracy is well within my rule-of-thumb-minimum of 3″ to 3.5″, but it’s enough of a difference that it should be noted. Here is the complete set of range results:
As of this writing, the usefulness of 5.7×28 mm FN ammunition in handguns for personal protection, in general, and for concealed carry in particular, continues to be debated. This caliber’s dissenters tend to favor the 9 mm Luger round for its larger projectiles and time-tested results. But for those civilians who have adopted 5.7×28 mm FN, it’s hard to argue with the reduced recoil, tighter patterns and guns with increased ammunition capacity.
Palmetto State Armory’s new 5.7 Rock Compact provides the top-notch trigger, desirable defensive-pistol features and the softer shooting characteristics of the standard pistols but in an easier to pack configuration that only sacrifices two rounds of ammunition capacity. For those who agree that the 5.7×28 mm FN is a viable, low-recoil defensive option, this compact-size pistol is a welcome addition to the PSA catalog that is listed for a suggested retail price of $499.
PSA 5.7 Rock Compact Specifications
Manufacturer: Palmetto State Armory U.S.A.
Action Type: delayed-blowback-operated, semi-automatic, centerfire pistol
Chambering: 5.7×28 mm FN
Frame: black polymer
Slide: 416 stainless steel
Barrel: 4.3″ carbon steel; QPQ finish
Rifling: six-groove, 1:9″ RH-twist
Finish: matte black
Magazine: 21-round detachable box
Sights: Glock-compatible; blade front, dovetailed square-notch rear
Trigger: single-action, 4-lb. 8-oz. pull
Overall Length: 7.70″
Height: 5.03”
Width: 1” slide; 1.25″ grip
Weight: 25.4 ozs. (with empty 21-round magazine and filler plate installed)
Accessories: owner’s manual, zippered soft case, two magazines, lock
MSRP: $499 (Model RO-101127)
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