Ruger may have gone back to the future when it chambered its new-for-2020 Ruger-57 handgun in 5.7x28mm (aka 5.7×28 FN), a round that has mostly languished for 30 years, but which is seeing a blip of interest in recent introductions.
Developed by FN back in 1989, the 5.7x28mm cartridge is similar in shape to the commercial .221 Fireball cartridge, but the two are not interchangeable.
Long known for its use in the FN FiveseveN handgun as well as FN’s personal-defense weapons, such as the P90 and the PS90 the 5.7 was intended to replace the 9x19mm Parabellum pistol cartridge for NATO use. The 5.7x28mm weighs only half what the 9mm does, allowing a soldier to carry double the amount of ammunition. Magazine capacity is also substantially higher.
At SHOT Show 2020, the .224-caliber cartridge has already been introduced in the aforementioned Ruger-57, (see TTAG’s full review here). Ruger’s involvement alone may broaden the round’s appeal beyond what FN was able to achieve, but others have also given the 5.7 a try recently.
CMMG, for instance, has has released its 5.7 AR Conversion Magazine, which holds 40 rounds of 5.7x28mm and is designed to fit and function in a mil-spec AR-15 lower receiver when paired with CMMG’s 5.7x28mm Radial Delayed Blowback upper receiver.
CMMG offers a complete line of firearms in Banshee and Resolute models that are designed for 5.7 AR Conversion Magazines. Each is built with CMMG’s Mk4 lower receiver and a dedicated 5.7x28mm Radial Delayed Blowback upper receiver and ship with one 5.7 AR Conversion Magazine. The magazines are $40 each.
And now Diamondback has jumped into the 5.7 pool with their new-for-2020 DBX57BGB, a semi-auto locked breech, dual-gas-piston pistol with an 8-inch barrel. It has a Magpul Handstop Kit and comes with a 20-round Five-seveN-compatible magazine. The brace is a rear Picatinny mounted, side-folding style. TTAG has shot this item as well, and as soon as the review is published, we’ll have the link here.
I’ve shot the 5.7 in the FN handgun and the PS90, as well as a 57Center PDW, and have loved it in all of them. The round has been superbly accurate in everything I’ve shot, and its performance in ballistic gelatin was eye-opening in terms of penetration. Its cost per round has always been a big drawback when shooting it against a 22 WRM pistol such as a Kel-Tec PMR30, but perhaps these new companies’ interest in it will improve the ammo selection and pricing.