The 5.7×28 is an interesting cartridge. Developed originally at NATO’s request as a possible replacement for the 9mm Luger for PDWs and pistols, it underwent a few changes, and I remember reading about it at that time. I recollect wondering if it would make the transition to the civilian world, thinking that it would be a great addition to a gun owners’ arsenal. It’s firmly my belief that the 5.7×28 cartridge is here to stay. I have come to this conclusion despite seeing it introduced to us in one pistol (the FN Five-seveN), and then practically being put on life support due to slow sales.
The problem wasn’t the cartridge – it was the fact that the only pistol able to chamber it for a long while was that lone FN pistol, an expensive ($1409 today) proposition. Many shooters wanted to add the 5.7 to their collection, but couldn’t afford to until Ruger, Kel-Tec, Smith and Wesson, and a few other manufacturers added a 5.7×28 pistol to their line-ups.
Palmetto State Armory 5.7 ROCK, Optics Ready Pistol W/ Threaded Barrell & Holosun 407K Sight $699.99
Live Inventory Price Checker
Palmetto State Armory (PSA) jumped on that particular bandwagon by offering its affordable (starting at $420. PSA website) ROCK 5.7 for sale in May of 2022. Now, many shooters can enjoy the punch of this centerfire .22. Coming in at less than a third of the price of the FN Five-seveN, this cost-effective PSA gun is being snapped up by savvy shooters wanting a hard-hitting pistol that makes little-bitty, very-close-together holes in a target without much felt recoil. Varmints especially fall into the bailiwick of this zippy little round, although that wasn’t its original intended purpose. Let’s take a quick look at the 5.7×28 cartridge first, then we’ll examine the ROCK 5.7 up close that PSA kindly sent for review.
5.7×28 Backstory
Developed by Fabrique Nationale and released in 1990 at the request of NATO as a possible substitute for the 9mm, the SS90 (as it was referred to) featured a 23-grain, plastic-core bullet at 2800 fps when fired from FN’s P90 PDW. When fired from that weapon, the cartridge could defeat a NATO CRISAT vest or a Level IIIA Kevlar vest at a range of 200 meters. Three years later, the SS90 was replaced by the SS190 with its 31-grain bullet at 2350 fps. It also featured a slightly shorter case to function in a pistol more easily. After a few more variations and further development of the 5.7×28 cartridge, the FN Five-seveN pistol went into production in 1998.
I won’t go into the military/NATO evaluations of the cartridge… suffice it to say it underwent a series of tests in 2002 and 2003, alongside the H&K-developed 4.6×30 cartridge. Those tests were terminated due to a bizarre turn of events, as H&K cried ‘foul!’ and testing was suspended.
Needless to say, the venerable 9mm was not replaced, but the civilian world gained a fun-to-shoot little round that excels at penetration, velocity, and lack of recoil. That leads us to the gun-of-the-hour, the PSA 5.7 ROCK.
PSA 5.7 ROCK
Announced in January of 2022 and available in May of that year, the PSA 5.7 ROCK has been a consistent seller for them. Owning a feature set similar to that of a more expensive pistol, the PSA 5.7 ROCK looks, feels and shoots like it should cost a couple of Benjamins more than it does. At last count, I saw 71… yup, 71… different models of PSA 5.7 ROCKs available on PSA’s website. That counts all 5.7s… those both in and out of stock, but it gives you an idea of how popular the round and the gun are. If they weren’t selling them, they wouldn’t make them. Can’t fool me! The guns sell well because the feature set outweighs the price tag.
Speaking of features, let’s take a look at the specs…
Specifications
- Model: PSA 5.7 ROCK
- Caliber: 5.7x28mm
- Capacity: 23+1
- Weight with Empty Mag: 25 oz
- Barrel Material: Carbon Steel With QPQ Finish; Fluted
- Barrel Length: 5.2″
- Twist Rate: 1/9″
- Thread Pitch: 1/2×28 TPI
- Front Sight: Co-Witness Sight, suppressor height, Glock-compatible
- Rear Sight: Co-Witness Sight, suppressor height, Glock-compatible
- Slide Material: 416 Stainless Steel with Sniper Green Cerakote Finish
- Action: Delayed Blowback Striker-fired; single-action
- Mag Catch: Reversible
- Safety: Trigger & Striker
- Accessory Rail: Picatinny
- Color: Sniper Green
- MSRP: $699.99 with Holosun HS407K X2 red dot
Observations
We have the measurements, weights, etc. listed above. Let’s take a more subjective look at this pistol… what do I like about it? Instead of doing pros and cons, I will write about what impressed me, and one thing that did not impress me. One downside that I saw with this pistol didn’t have anything to do with the pistol, but with the cost of ammo. Be ready to spend around $30 for a 50-round box of FMJ cartridges. Expect to pay more for soft points or other expanding rounds. You can buy ammo in bulk, but it still ain’t cheap. (The reloader in me found that the round took small rifle primers and about 6 – 10 grains of powder. Reloading is an option).
Feel.
This is a 5.2-inch-barreled, full-size pistol. It fits my hand very well. I received this and PSA’s Dagger Compact 9mm for review. After handling the Dagger, I picked up the ROCK and my hand said “Ahhh…”. Well, maybe not literally, but there is more room in the grip. Granted, the Dagger is a compact pistol and as such feels better than its “G”-word competitor in my hand. But, the full-size ROCK has a longer grip and is very comfortable to hold. My friend Ed, a former deputy who regularly carries a Walther PPQ, really liked the larger grip frame of the ROCK over that of the Dagger. He is tall, with large hands. It’s a subjective call.
Red Dot.
This model comes with the Holosun HS407K X2 red dot sight. This 6-MOA sight is, well, tiny. It is shorter and narrower than many other dot sights I’ve used over the years. With its auto-on and –off feature, you’ll have 50k or so hours of battery life. Holosun makes good stuff.
Grip Texture.
I noticed first with the Dagger that the grip texturing is very effective. I like a rough grip texture — I’m handy with a soldering iron in the stippling department — but this grip works very well. When you pick the gun up, there isn’t a “grabby” feel to the grip. It’s only when you crank your grip down that you feel the stickiness. Put the gun in your hand, grip it tight, and try to move it around with your other hand. I can’t get it to move much at all. I experience the same feeling with my Springfield Armory Hellcst RDP… SA uses a similar texturing that feels almost smooth until you grip hard. The texturing here would be easy on clothes.
Safe.
The ROCK uses a striker and trigger safety. The striker is blocked unless the trigger is pulled, and the trigger is hinged like that on an S&W M&P 2.0. There is no center blade. I like this system – it works well, doesn’t affect the trigger pull, and doesn’t pinch my finger like some bladed triggers do.
Sights.
The ROCK, like the Dagger Compact, uses suppressor-height, co-witnessing sights that are Glock compatible. They line up with the Holosun HS407K X2 red dot that came with the gun (after a bit of zeroing… it needed adjusting but was no big deal). The Holosun is mounted directly on the gun, no adapter plate is needed, but a couple of plates are included if you need to install another type of red dot. The ROCK allows you to directly mount any Shield footprint optic, excluding the Leupold Delta Point Pro.
Magazines.
You could load all but three from a box of 50 5.7×28 cartridges in the two included steel magazines, plus one in the chamber… magazine capacity is 23 rounds. Not too shabby! They load like .223 AR mags load – push the cartridge down until it clicks into place … don’t try to slide it in from the front. That makes sense since it’s basically a tiny bottleneck rifle cartridge being loaded. They do get rather hard to press down after you’ve loaded a few, so be prepared to push with some force.
About the magazines, PSA’s website has this notice:
“While this magazine will fit in a Ruger 5.7 mag well, we cannot guarantee that it will function in a Ruger 5.7 Pistol
*Due to geometry differences, the 5.7 Rock 23 round *magazine will fit in a Ruger 5.7 Pistol and our 5.7 Rock pistol, however, the function cannot be guaranteed.
A 20-round Ruger 5.7 magazine will NOT work in a 5.7 Rock.”
So now you know.
Case.
The ROCK and the Dagger Compact were both shipped in soft-side, FDE zipper cases with holders for both magazines and the lock. A velcro strap for the gun’s grip rounds out the package. This case is a very nice “extra” that was not expected.
Threaded Barrel.
Add a suppressor easily via the 1/2×28 TPI threaded barrel. Don’t lose the rubber gasket under the thread protector – you’ll need that.
Trigger.
The only negative observation I have about this particular pistol concerns the trigger. I measured it at seven and a half pounds. It had about a half-inch of take-up. That wasn’t the issue. The trigger pull itself was very hard – after take-up, you hit the “wall” and it takes a lot of pressure to trip the sear. I pulled the sights off target a couple of times trying to cope with the pressure required to fire the gun. I would hope that, after a few hundred rounds, the trigger would smooth itself out but as it is now, it sure took some concentrated effort to keep the sights or the dot on the target while pressing it.
That honestly is the only remotely negative aspect I noticed about this gun. Other shooters validated my opinion on the tough trigger. Several other reviews I read online praised the trigger on their sample, so hopefully, the one I got was a one-off.
Field-Stripping The ROCK
The take-down drill is a bit different than your typical Glock-style procedure. It’s more like the takedown of a couple of .22 LR pistols I’ve handled.
First, pull the magazine and make sure the chamber’s empty. Then, remove the mag and pull the slide takedown lever down. Grasp and pull the slide to the rear about 1/2″. After a trigger pull, move the slide forward not quite an inch, and lift it off the frame rails. Do not attempt to slide it off the front of the frame… that’s not going to happen. Just lift it off the rails.
To reverse, place the slide back over the frame, about an inch forward of the locked position. Press it down and work the slide to the rear. That should do it. If you get stuck go to the PSA 5.7 ROCK owner’s manual. Go to page 17.
The key to being able to remove the barrel for cleaning lies in the thread protector’s rubber gasket. I tried pulling the barrel out at first and was unsuccessful until my friend Ed tried it and saw, then removed the gasket. I hadn’t seen it, but he did. Once the gasket was off, the barrel came right out. Hang on to that little rubber circle!
How’s It Shoot?
I bought a couple of different brands of 5.7 ammo… not something I say lightly at its current cost … and headed to my backyard range. As I said above, I had reviewed the Ruger 5.7 before, so I had some idea of what to expect in terms of recoil, flash, and noise. Not so much of the first, more of the last two. This gun was no different. When you consider that the 9mm operates at a max pressure of 38,500 psi and compare it to the 5.7×28’s more than 50,000 psi, you will know when you touch one off. Remember that the original military purpose of developing the 5.7 was to defeat body armor at a distance. So, it’s bound to attract attention when you pull the trigger.
One of the two brands of ammo I bought was the FN-manufactured 40-grain FMJ (FN GUNR, #SS201 target ammo). The first two targets are the FN load and the third, black, target is the Federal American Eagle 40-grain FMJ. Targets were set at 25 yards. Here’s what happened…
It took a while to discover that the red dot wasn’t quite zeroed, so we switched to irons. The tall sights were easy to acquire, but the results were not as good as they could have been if we had just stuck with the irons to begin with. I finally got the dot zeroed to co-witness with the irons, after our shooting session. The gun popped every clay pigeon I put the dot on – it’s accurate, in spite of the trigger. Unless you’re hunting varmints with this gun, this FMJ ammo is surely OK for practice.
Conclusion
If you are looking to add a unique firearm to your gun safe and want that gun to put bullets out of its muzzle at very great speed, then you might want to check out the PSA 5.7 ROCK. The ROCK is built to a high standard, feels good in the hand, and is accurate and reliable. I really like shooting it — the lack of recoil makes up for the blast and flash. If ammo was a bit cheaper, I could packing this thing around at home for woods walks, etc. Put one in your hand and give it a try – you’ll be glad you did!
About Mike Hardesty
With experience spanning over 45 years, Mike Hardesty has long enjoyed shooting and reloading. An inveterate reloader, he casts bullets and reloads for a diverse array of firearms, each handled with long-practiced precision. Living in rural Indiana, his homestead boasts a personal 100-yard range where he shares his love for guns to his four sons, their wives, and eleven grandchildren. As a recognized author, his writings have been featured in notable platforms like Sniper Country, Bear Creek Arsenal Blog, Pew Pew Tactical, TTAG, Dillon Precision’s Blue Press, and Gun Made, revealing his ongoing passion for firearms at the age of 72.
