Building on a spate of recent new firearm releases chambered for the once-exotic FN 5.7 round, the aisles at SHOT Show this month seemed to reinforce that the caliber is here to stay. 

While the 5.7x28 was originally just designed for FN's PDW program-- which led to the P90/PS90 and the Five-seveN series pistol – the now-NATO standardized cartridge caught a boost from Ruger in late 2019 with the Ruger 57 pistol followed soon after at SHOT Show 2020 by the prototype Diamondback DBX large-format pistol. Since then, KelTec has brought its P50 pistol to market, the CMMG Mk57 has appeared, and the DBX has started to appear on dealer's shelves. In the meantime, FN updated the Five-seveN with new features and colors. 

With Vista's ammo brands (Federal, Speer, etc.) pumping out new 5.7 rounds as fast as they can to keep up with the trend, even more 5.7-chambered guns are inbound. 

PSA Rock 

Palmetto State Armory showed off its new 5.7mm Rock pistol, a polymer-framed striker-fired handgun that uses Ruger 57-style 23-round mags – although the base Ruger mags aren't compatible due to the longer grip length of the PSA. The guns are in production now in two variants, a $499 base model and a $550 optics/suppressor-ready model. Delivery is set to begin in about three months. 

PSA Rock 57
The PSA Rock is Palmetto's budget answer to the Ruger 57 and FN Five-seveN series pistols. (Photo: Chris Eger/
PSA Rock 57
It will be available in both a basic model and a more feature-rich version that has an RMR cut and threaded barrel. (Photo: Chris Eger/



More DBX choices

Diamondback's DBX, a sweet little gun that uses an adjustable dual gas-piston action and dual aluminum receivers, was introduced in black in 2020. This year it will also be available in dark gray and an FDE-ish tan color as well. Overall length, sans any accessories, is 15.25 inches with an 8-inch stainless-steel barrel while the weight of the DBX is right at 5 pounds. 

Diamondback DBX
The top Pic rail, handguard with M-LOK slots, and rear accessory rail give the little DBX a lot of plug-and-play options. It accepts FN pattern mags. (Photo: Chris Eger/


KelTec P50 goes long

KelTec was showing off the P50 on the range and on the floor itself. 

They also added a $300 carbine kit that includes a fairly legit side-folding stock and a 16-inch barrel that is NFA compliant so long as you install both pieces. If you want to file the Form 1 and just install the stock, that's you. Yes, we know, the NFA should be abolished. 

KelTec P50
The P50, shown with and without the soon-to-be-released carbine kit installed. (Photo: Paul Peterson/

For now, at least, it looks like the 5.7 is just getting started. 

revolver barrel loading graphic