Which calibre of bullet is stronger, the .45 ACP or the 9mm Parabellum?
9mm travels faster but has less energy on impact(stopping power) .45 travels 200-400 feet per second slower but has alot more energy,9mm may go right through a person thus not depositing all of its kinetic energy in the target, but a 45 will almost never exit and tends to transfer all of its energy in the target.
