F2000, like most guns in the game, is a joke weapon that I only use when I want to humiliate little baby buffalo.
Delta, there's only really three or four worthwhile primary weapons in this game, if you want to fulfill a certain niche in this game. The M16 is not one of them, for god's sake, the M93 is a better weapon. The FAMAS is the god weapon, you can technically do anything with it, and you can literally run any attachment on it. TAR-21 is an all-around gun as well, but Full-Auto. It's worse than the FAMAS at long range, but is superior at close range. The MP5K is unmatched at close range. Period. If you really want long, long range kills, the Barrett is pretty much the best choice for a Sniper rifle.