Semi-Automatic Fire is a way of firing one round of ammuntion at a time.
Semi-automatic was added in the update that added switchable fire modes and overhauled the melee system. There were 2 new ways of firing military projectile weapons, semi-automatic, available on all military weapons, and burst fire, available on only certain weapons. The semi-automatic fire mode fires only one shot at a time. It is primarily used for controlled fire when trying to conserve ammo.
The semi-automatic fire mode is extremely useful for dispatching zombies, as you can conserve your ammuniton instead of accidentally firing more than one shot. The lowered recoil and raised accuracy also makes it a good way of firing at targets from a distance. Many survivors who adopt a sniper playstyle combine this fire mode with equipment such as a long range rifle, such as the 7.62x51mm rifles, and attachments such as a forward grip, and a long range scope, such as the ACOG or SUSAT.
- Semi-automatic is always more accurate than automatic fire.