>>517850
Try shooting through a bush with .223.
Then try it with something of the same energy value (ftlb) but lower speed/higher mass.
Answer: The slower cartridge actually moves better through bush/leafs. Higher speed/low mass one yaws immediately, lower speed/higher mass just keeps plugging along in a straight line. Same energy though!
The math: Momentum is mass times speed. Kinetic energy is mass times velocity squared over two. So for kinetic energy, speed is exponentially more important, whereas for momentum its equivalent value to mass. And since momentum is whats CONSERVED in a physics situation, if you can pick between mass and velocity… the mass is comparatively more important.