Editing FN F2000 (section)

===Operating mechanism===
[[File:FN F2000 partially disassembled.jpg|thumb|left|Partial disassembly (cartridge on bolt face)]]

This [[selective fire]] weapon is a [[Gas-operated reloading|gas-operated]] design utilizing a short-stroke piston system driven by propellant gases diverted into the gas cylinder through a port in the barrel; it fires from a closed bolt position. The weapon is locked with a rotating bolt which features 6 radial locking lugs, a spring-powered [[extractor (firearms)|extractor]] and ejector. The [[chamber (firearms)|chamber]], bolt, and ejector mechanism can be accessed by flipping up a hinged inspection cover in the receiver, behind the optical sight housing.
[[File:PISTONM16.gif|thumb|left|short-stroke gas piston]]

The F2000 uses a unique ejection system, ejecting spent cartridge casings forward and to the right side of the weapon, through a tube running above the barrel. This method of ejection provides for fully ambidextrous operation; the rifle can be used without any modification by both right and left-handed shooters. This ejection pattern was achieved by using a swiveling polymer tray, which intercepts the empty casing from the bolt face immediately after disengaging from the extractor. As the empty casing is extracted it is held while the rocker assembly tilts to lift it above and clear of the feed path as the next round is stripped from the magazine by the bolt head. The casing is fed into the tray located in a cavity in the receiver wall, which then pivots the cartridge case and directs it into a chute (above the barrel); the case is discarded from the tilting tray by being impacted by a pin on the moving bolt carrier upon its forward return. Only when the ejection tube contains more than five cases is the first of them ejected forward through a port just behind and to the right of the muzzle. Any cases remaining after firing has ceased, can be cleared by tilting the rifle muzzle down.

This system is patent protected (patent number 5675924 dated 14 October 1997 by René Predazzer<ref>{{cite web |url=https://patents.google.com/patent/US5675924 |title=Ejection device for firearm |author=Predazzer, Rene |work=Google Patent Search }}</ref> and patent 6389725 from February 25, 2000, author Charles Denuit).<ref>{{cite web |url=https://patents.google.com/patent/US6389725 |title=Fire arm with forward ejection or ejection brought to the fore-part of the firearm |author=Denuit, Charles |work=Google Patent Search }}</ref> The ambidexterity provided by forward ejection is its most obvious benefit, and removes many of the tactical and user difficulties (such as lack of ambidexterity, and gas and debris released in close proximity to the shooter's face, as in the [[SA80]] or [[OC-14]]) that bullpup designs usually create.