What does "full metal jacket" mean?

Answer by  ParrotPirate (477)

Full metal jacket refers to the type of bullet used in certain types of ammunition, usually for military use. FMJ rounds have a copper of other metallic coating over the actual lead bullet of the cartridge. This causes higher velocity and more penetration. FMJ are most often rifle, sub-machine gun or machine gun calibers.

Answer by  kb2008 (50)

"Full metal jacket" refers to a style of bullet wherein the soft metal of the bullet is encased entirely by a harder metal. "Jacket", in this case, refers to the coating of aforementioned harder metal.

Answer by  malone (4817)

A full metal jacket is a bullet that consists of a soft core, usually lead, that is covered in a harder metal, usually copper.