ARC Raiders Ammo: Light for Raiders, Heavy for Machines

The two classes

Light ammunition feeds submachine guns and similar weapons. It is plentiful, it comes in large magazines, and it is effective against unarmoured targets — which in practice means other Raiders. Heavy ammunition feeds rifles and hits hard enough to penetrate the armour plating on ARC machines. It is scarcer, comes in smaller magazines, and it is the only reliable way to break a large machine. So the rule of thumb is exactly as simple as it sounds: light for people, heavy for robots.

Why you carry both

A raid contains both. You will meet Raiders and you will meet ARC, and a loadout that answers only one of them is a loadout that loses the other fight. That is why the standard advice is two weapons with different ammunition types rather than one weapon and a bigger bag. It costs weight and a slot, and it means you always have an answer. The corollary: if you only carry one weapon, make it the one that handles the threat you actually meet. On a map where you are dying to machines, that is heavy. On a map where you are dying to players, it is light.

The magazine problem

Heavy ammunition comes in smaller quantities, so a heavy weapon that fires fast empties quickly and leaves you reloading at the worst moment. That is a real cost of the class and it argues for a heavy weapon with a slower, more deliberate firing pattern. Light weapons have the opposite profile: plenty of rounds, weaker per hit, and a tendency to encourage spraying. Against an armoured machine, spraying light ammunition does almost nothing but does tell the machine exactly where you are.

It interacts with the bench

Ammunition is produced at the workshop, which means your supply is a function of materials rather than of money alone. That makes ammunition a progression concern rather than a shopping trip — the workshop page covers which bench produces what. Running out of heavy ammunition mid-raid is a common early experience, and it is why players learn to fire in short bursts at machine weak points rather than holding the trigger. The enemy page covers where those weak points are, and the rarity page explains why a heavier weapon is not automatically the better one.