As the default human weapon, the Rifle recieves much use during all parts of a normal game of Tremulous. Nothing is particularly noteworthy about this weapon, besides the fact that it is one of the most quickly-firing weapons in the game. Its accuracy is good enough to hit a dretch consistently at medium range. It can be used for a variety of duties, including supporting fire against large targets, but it does none of them particularly well. It is, however, free.
En masse, the rifle can do significant damage, although it is rarely used in that fashion.
NOTE: The rifle becomes much less useful when it's reloading. If you get caught reloading in the heat of battle, the DPS becomes something more like 33-36. As long as you can eliminate the enemy before this happens, the rifle is an excellent and free medium-range weapon.