I know this is an oldie but a goody. Since kinetic energy increases 4 fold when doubling velocity what is the majic number at which bullet velocity starts to "out weigh" mass...pun intended. Epecially with all the designer rounds, bullet mass vs. velocity deserves a second look. Also, what about pistol cartridges that can reach over 2000 ft per second? (7.62x25mm) Worth another look? Interesting article on the subject: Tokarev 7.62x25mm vs. m1911 .45 ACP: Velocity or Bullet Mass?