A fully automatic firearm operates as a self-loading weapon that continues to cycle and fire rounds as long as the trigger is held down.
Here's a breakdown of the process:
The Core Principle
Based on the provided reference, a key characteristic of a fully automatic firearm is that it continuously chambers and fires rounds when the trigger mechanism is actuated. This means that unlike a semi-automatic firearm, where one pull of the trigger fires one round and requires a new pull for the next shot, holding down the trigger on a fully automatic weapon initiates a continuous firing cycle.
The Continuous Firing Cycle
When the trigger of a fully automatic firearm is pulled and held, the following actions happen rapidly and automatically:
- Firing: The hammer (or striker) strikes the primer of the chambered round, igniting the propellant.
- Cycling Mechanism Activation: The energy released from the fired round (typically through gas pressure or recoil) drives the firearm's operating mechanism.
- Extraction: The spent casing is pulled out of the chamber.
- Ejection: The spent casing is thrown clear of the firearm.
- Feeding/Chambering: A fresh round is taken from the magazine or feed mechanism and pushed into the chamber.
- Locking & Firing: The action locks, and the hammer or striker is released again (or remains in a position to strike as soon as the action closes, depending on the design) to fire the new round.
Steps 3 through 6 repeat continuously as long as the trigger is depressed and ammunition is available. This creates the sustained burst of fire characteristic of automatic weapons like machine guns or some assault rifles.
Automatic vs. Semi-Automatic
Understanding the difference highlights how a fully automatic weapon works:
| Feature | Semi-Automatic Firearm | Fully Automatic Firearm |
|---|---|---|
| Trigger Action | One pull = one shot | One pull (held) = continuous shots |
| Recocking | Recocked by the firing cycle | Recocked by the firing cycle |
| Next Shot | Requires trigger release and new pull | Fires automatically as long as trigger is held |
Examples
- Machine Guns: Designed for sustained automatic fire.
- Some Assault Rifles/Submachine Guns: Often have a selector switch allowing the operator to choose between semi-automatic, burst fire, and fully automatic modes.
The mechanism ensures that the firearm is self-loading, using the energy of the fired cartridge to prepare the weapon for the next shot without manual manipulation, and crucially, it continuously performs this cycle when the trigger is actuated.
