This is an FN Five-seveN USG, which fires the 5.7x28mm cartridge. This one is black, with adjustable sights and 20rd magazines.
This firearm was purchased in 2010.
The 5.7x28mm cartridge was designed to be able to penetrate body armor when fired from a handgun (a quality which FN marketed as "anti-terrorist"), but there are several ways in which it does not live up to this goal. First, the velocities achieved from a four inch barrel are disappointing. Second, fearing a public backlash, FN sells only highly frangible, lower velocity cartridges to the general public. Third, Federal law bans most types of "armor piercing" handgun ammunition based on the bullet's construction. So contrary to the hype, this cartridge and the guns that fire them should not be viewed as armor piercing.
The standard SS197SR should make a great varmint round. I'll keep a magazine loaded and ready to go.
I should try out the new Speed Gold Dot offering in this caliber.