BrickArms Spy Pistol
"The Beretta .25 is a ladies' gun 007, try this.."

One piece of equipment that LEGO Bond never leaves home without is his handgun, worn inconspicuously in a shoulder holster. While not the most powerful gun in the world, it is compact and reliable.

The BrickArms Spy Pistol is also available in a silenced version.

$1
 
(Disclaimer: All BrickArms tiny toy weapons are made of solid ABS plastic, designed to be used with LEGO toys. They cannot shoot bullets and cannot be made to fire bullets in any way. Again, they are a TOY! T-O-Y Toyee!)