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 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 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 Variants F2000 Tactical The F2000 Tactical railed variant is similar to the standard model, but it lacks the optical sight, and comes instead with an extended top receiver MIL-STD-1913 rail with flip-up iron sights allowing for picatinny rail accessories to be fitted. F2000 Tactical TR The F2000 Tactical TR variant is similar to the F2000 Tactical model, but includes a triple rail handguard for add-on accessories. FS2000 Intended for civilian ownership, the FS2000 is a semi-automatic version of the F2000 that first became available in June 2006. The FS2000 Tactical model is equipped with an extended barrel with a permanently attached muzzle brake and a 1:7 in right hand twist rifling rate; the bayonet lug was not included on the FS2000 rifles. 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. A small number of the early models featured a stepped barrel contour as well as a demilled bayonet lug. Measurements on the stepped barrel's rifling were as long as the non-stepped barrel, revealing that the stepped barrel is not simply a shorter F2000 military barrel with an extended muzzle brake which is similar to the PS90. A variant of