 FACT: When the ballistics expert examines the bullet, he declares it  to be "4.2 mm," which would be .169", slightly less than the .172"  of "17 caliber" weapons. He also declares the mass to be 20.53 grams  (316 grains). Even though 23 carat gold is somewhat denser (1.67:1)  than the lead alloy used in modern arms, this is still almost  thirteen times as massive as the largest 17 caliber bullets  manufactured (25 grains). It would look more like a thick needle  than a bullet, being nearly two and three quarters inches in length  and would be nearly impossible to stabilize.