Home » Gun Information » Gun Glossary | Gun Terminology » Fully Automatic (Full-Auto) Fully Automatic (Full-Auto):A fully automatic (full-auto) firearm is a design that continuously feeds cartridges, fires, and ejects cartridge cases as long as the trigger is fully depressed and there are cartridges available in the feed system. Share:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Pinterest (Opens in new window)