the best non dlc weapon in the game is the mirv but another non dlc game which i rate as the most practical (ammo, firepower, and wieght) is vengance. Vengance is a named gattling laser that at fully repaired does about 130-140 or so damage. it can be found in the back of the deathcalw sancuary behind a rock piller by a small pool of water. if you did the finding out about rivet city's history part of the survival guide ammo only costs 1 cap each and usually is stocked in 1000s-10000s. its one draw back is that it wieghs alot, 15-20 or so.