The Ruger 57 is a semi-automatic handgun chambered in 5.7x28mm. The caliber delivers low recoil and high velocity, which works well for both self-defense and target shooting. A 20-round magazine means fewer reloads during a range session, which sets it apart from most pistols in this class. 
 

Key Specifications 

• Manufacturer: Ruger 
• Model: 57 
• Action: Semi-Automatic 
• Caliber: 5.7x28mm 
• Barrel Length: 4.94 inches 
• Capacity: 20 rounds 
• Finish: Cobalt Cerakote (Grey) 
• Material: Polymer Frame 
   

Features 

 
The grip is textured and the manual safety is ambidextrous, making the pistol accessible to both left- and right-handed shooters. The through-hardened billet steel slide has pre-drilled lightening cuts and comes ready for optic mounting. 
 
Sights are a fiber optic front paired with an adjustable rear, which gives fast target acquisition across varying light conditions. The alloy steel barrel has a black nitride treatment for wear resistance. Disassembly requires no tools and no trigger pull.

The Ruger 57 Cobalt in 5.7x28mm draws strong opinions from both directions.

Owners who like it point to the light recoil and high velocity of the 5.7x28mm round, which makes fast follow-up shots manageable. The 20-round capacity is a consistent plus, and most users find the accuracy solid for both range work and defensive use.

The main complaints center on ammunition. The 5.7x28mm round is harder to find locally than 9mm or .40 S&W, and it costs more per round. Some shooters also report that the grip geometry doesn't fit all hand sizes well.

Comparisons to the FN Five-seveN come up frequently. The debate over whether 5.7x28mm is practical for self-defense relative to more common calibers is a recurring thread in user discussions.