Well 47 does have some heavy weapons, like the minigun who fires over 100 bullets per second. And it also depends on what weapons you give him. Because he almost always sneaks around he never brings stuff like rocket launchers and stuff, but I'm sure he's capable of getting one or handling one...
Anywho, 47 was made out of several people, Lee Hong, Pablo, Boris, the doctor, and that guy who plans to blow up the hotel. This gives Hitman increased speed of a normal human (yes, all of their speed was given to him), same with strenght, IQ, marksmanship, durability(the druglord Pablo could take more than 20 shots in his body and still stand), reflexes. This is why 47 has a hitrate of 100%, never fails a mission, always succeeds to plan a way through his missions even though sometimes he is ambushed by other people. Hitman is by far beyond Jill who took down Nemesis, Hitman has some damn good weapons and he could easily think out a plan AND execute it...