The FN FS 2000 is the civilian-legal, semi-automatic version of the F2000 that first became available in June 2006 manufactured by Fabrique Nationale de Herstal (FN Herstal).
The FS2000 is equipped with a 17.4-inch barrel with a permanently attached flash suppressor and 1/7 right hand twist rifling; the bayonet lug was not included on the FS2000 carbines. The FS2000 has an overall length of 29.1 inches and weighs 7.6 pounds when empty. Compared to the M4 Carbine with a fully collapsed stock (29.75" and 6.49 lb empty), the FS2000 is slightly shorter and heavier. The trigger pull was found to vary between 6-11 lbf. The lower hand guard can be removed in the same manner as the F2000 to accept the same variety of accessories. It comes with a Picatinny rail optic rail along with backup iron sights. The rear flip-up National Match-sized aperture is adjustable for windage, while the removable front sight is adjustable for elevation. The FS2000 is not configured from the factory to have a drop-free magazine system due to the friction from the removable dust gaskets. The magazine needs to be pulled out manually. It should also be noted that the rifle does not have a hold open device...the bolt does not stay rearward after the last round is fired. A small number of the early models featured a stepped barrel contour as well as a de-milled bayonet lug. A measurement of the stepped barrel's rifling was as long as the non-stepped barrel, revealing that the stepped barrel is not simply a shorter F2000 military barrel with an extended flash hider. FN Herstal has recalled approximately four hundred early FS2000 carbines in July 2006 due to the heavier military firing pins causing slam fires with commercial ammunition. The fixed carbines are equipped with a reduced mass firing pin, captured firing pin spring, and a revised bolt. Some users have experienced light primer strikes and short-stroking with the recalled parts using certain types of ammunition.
There is some speculation that FN Herstal plans to release a variant of the FS2000 with the factory F2000 1.6x magnification scope, and does not include the grenade launcher firing computer.