Mail was effective against slashing blows and missiles. Middle 3rd century BC Mechanical artillery began to use torsion in addition to tension power. Torsion allowed larger and more powerful engines to be built. Torsion catapults could send a javelin 800 yards. Catapults hurled arrows and darts, ballista hurled stones.
Romans use the gladius a two-foot long stabbing sword.
Later the spatha, the long slashing sword of the barbarians, becomes popular. 1st century BC Romans develop the pilum, a five foot long weapon with one-third of it being a spear head. It had short range but the head was of soft iron and bent back when hitting an object. This prevented it from being thrown back at them and helped it hook into an enemy's shields. 70 Roman catapults reported to be able to send 55 pound stones 400 yards and more.