Editing FN F2000 (section)

===Grenade launcher===
[[File:FN GL1.png|thumb|GL1 grenade launcher, not mounted]]
[[File:Pripadnik Slovenske vojske.jpg|thumb|GL1 mounted on F2000]]

One of the modules developed for the F2000 system is a proprietary lightweight 40&nbsp;mm underslung GL1 grenade launcher (empty weight 1&nbsp;kg) that uses standard low-velocity [[40&nbsp;mm grenade|40×46mm]] grenades.<ref>[http://www.fnherstal.com/index.php?id=271&backPID=265&productID=89&pid_product=297&pidList=265&categorySelector=7&detail= GL1 40&nbsp;mm LV] {{webarchive|url=https://web.archive.org/web/20090322012754/http://www.fnherstal.com/index.php?id=271&backPID=265&productID=89&pid_product=297&pidList=265&categorySelector=7&detail= |date=2009-03-22 }}, FNHerstal.com</ref> The launcher is a single-shot breech-loaded reverse [[pump-action]] weapon with a barrel that slides forward for loading and unloading (like the [[M203 grenade launcher]]), locked by axial rotation of the barrel.<ref>{{cite web|url=http://www.fnherstal.com/typo3temp/pics/a417e702b9.jpg|title=Pictured: FN F2000 Standard with Grenade Launcher|website=fnherstal.com|access-date=7 May 2018|url-status=dead|archive-url=https://web.archive.org/web/20160304065827/http://www.fnherstal.com/typo3temp/pics/a417e702b9.jpg|archive-date=4 March 2016|df=dmy-all}}</ref>

The grenade launcher's trigger is installed directly under the F2000's trigger so that it can be manipulated without removing the shooting hand from the rifle's pistol grip.<ref>{{cite web|url=http://www.fnherstal.com/uploads/pics/f2000_std_trigger1.jpg|title=F2000 pictured with standard trigger and GL1 grenade launcher with flip up sights|website=fnherstal.com|access-date=7 May 2018|url-status=dead|archive-url=https://web.archive.org/web/20150924014256/http://www.fnherstal.com/uploads/pics/f2000_std_trigger1.jpg|archive-date=24 September 2015|df=dmy-all}}</ref> The double-action trigger lets the operator "try again" if the grenade's percussion type primer doesn't ignite. The breech release button is found on the left side of the launcher body, like on the M203. The grenade launcher comes with a basic flip-up ladder sight, but it was intended to be used with a specially designed optoelectronic fire control system designated FCS, developed in cooperation with the Finnish company Noptel.

The aiming module is installed in place of the standard optical sight and becomes the weapon's primary sight when mounted, but its main purpose is to accurately determine and indicate the range of a grenade target. The module is powered by a 9 V battery pack, installed in the stock, behind the magazine well. The power pack is also intended to power any other tactical accessories or systems that could be introduced. The FCS integrates a low-power laser rangefinder (precise to within ± 1 m), a day-time aiming channel with an electronically projected reticle, a measured range display reading and a diode elevation adjustment indicator.

The fire control system calculates a firing solution manifested by the barrel's angle of elevation using target range information from the laser rangefinder (the rangefinder is activated by pushing a button on the pistol grip, below the trigger), corrected manually by the shooter through a push-button interface (add/subtract buttons) on the FCS top cover to take account for head or tail winds that could affect the desired range. The F2000 FCS also contains software with the ballistic properties of up to six types of 40&nbsp;mm grenades and can be reprogrammed to take advantage of future munition improvements. Batteries for the FCS are located in the bottom of the buttstock.

After obtaining a range measurement, the distance to the target is displayed on a [[liquid crystal display|liquid crystal]] screen and the elevation diode flashes red. Once a correct elevation has been achieved by tilting the rifle, the diode changes color to green indicating the weapon is ready to fire{{citation needed|date=February 2013}}