Actually, that’s not entirely true. In the movies none were shot, sure. But in the book Muldoon (of ‘clever girl’ fame) actually does blow the leg off a raptor with a SPAS-12 and tranquilized the T-Rex with a goddamn rocket launcher. Dr. Grant also kills a few raptors in a melee with some hypodermic syringes filled with hyper-toxins or some shit.
As for the lack of heavy weapons on the island, John Hammond (the eccentric old guy) did not permit Muldoon to keep launchers and stuff on the island for fear of ‘hurting the dinosaurs’. Originally Muldoon wanted AT4s, but Hammond said ‘fuck that, you work for me’. In the end there were net launchers, shock prods, and some tranq darts. Not much for safety, really. There’s actually quite a lot different between the book and movie.
Geez, guys, go read a book.