Women must feel a great sense of comfort in the parity they’ve achieved in Hollywood. Here’s a movie that proves they can star in a buddy-cop action comedy every bit as crass and dumb as the ones male teams have been making for years.

The mismatched duo are Sarah Ashburn (Sandra Bullock) and Shannon Mullins (Melissa McCarthy). Sarah is a straight-arrow, by-the-book, ambitious FBI agent sent to Boston to identify and arrest a big-time drug dealer no one’s ever seen, while Shannon is the loose cannon local plainclothes cop she’s forced to partner with. Naturally their styles clash in every respect, especially since Mullins—in conformity with the persona McCarthy’s built over several pictures—is an abrasive, foul-mouthed type whose very presence offends the mousy, businesslike Ashburn.

The “procedural” element of Katie Dippold’s script doesn’t bear much scrutiny. The unlikely pair’s tracking down of the villain leads from goofy street dealer Rojas (Spoken Reasons) through slutty Russian Tatiana (Kaitlin Olson) and sleazy club owner LeSoire (Adam Ray) to nasty henchman Julian (Michael McDonald) and ultimately kingpin Simon Larkin, whose identity will not be revealed here. (Just think of the least likely suspect and you’ll have it.) Both women have harassed superiors—Sarah’s is demanding Hale (criminally used Demian Bichir) and Shannon’s Captain Woods (Tom Wilson). And there are a couple of frazzled DEA agents (Dan Bakkedahl and Taran Killam) whose ire the women spark for undermining their long-term nvestigation. (The former is an albino, which looses comic tirade after tirade from the insensitive Mullins.) Along the way there are plenty of face-offs, gun battles and car chases, as well as the obligatory sequence where our heroines are captured and threatened with death. And that’s after they’ve armed themselves to the teeth with the heavy weaponry Mullins has accumulated in her refrigerator, in a sequence that goes back to the Rambo pictures.

But the really “significant” part of “The Heat” is the way these two mismatched partners bond during their time together, becoming BFFs in the process. This involves the rigid Sarah being forced out of her shell by the raucous, raunchy Shannon—in sequences like a long digression in which they get plastered at rundown bar, dance and do other embarrassing stuff, and wind up bosom buddies. It’s all the usual drivel—including lots of low-rent humor involving Shannon’s estranged family, who are depicted as loudmouthed numbskulls so stereotypical that they should put all Beantown residents into apoplexy—except for one truly horrendous sequence in which Sarah tries to assist a choking man by giving him an amateur tracheotomy. That’s a scene that’s so visually ugly and unfunny—not to mention utterly extraneous—that it shatters the movie’s crudely comic tone, which never recovers.

As for the stars, Bullock is doing yeoman straight-woman work here, looking properly pained and embarrassed, though it’s hard for her to pull off Sharon’s warming toward Shannon, whom McCarthy plays with her customary rude, abrasive shtick. One supposes that McCarthy is trying to be the modern female version of Jackie Gleason’s Ralph Kramden, but in her hands it’s a routine that’s getting old fast, primarily because Kramden was always obviously deluded and wrongheaded, and so deserving of sympathy, while the McCarthy’s characters—like this one—are portrayed, in the contemporary fashion, as obnoxious but right, and so merely irritating. Sure, she always proves to be a softie in the end, an oversized broad with a hard surface but a heart of gold, but frankly it’s a matter of too little (or too much) too late. One might be surprised that McCarthy has coasted as long as she has with this one-note kind of performance, but audiences today seem much more tolerant of repetition than they used to be. As for the supporting cast, apart from Bichir—who’s really too good an actor to be wasted in such a thankless role—they all do what’s expected of them, with Wayans, of all people, coming across as the most laid-back and likable of the bunch as a fellow agent who’s sweet on Sharon.

Technically the movie is okay, though Feig’s flat direction is compounded by sluggish editing from Brent White and Jay Deuby, which appears to have been dictated by the a desire to give the leading ladies free rein for their mugging and other bits of business. The result is a picture that drags on for nearly two hours, far too long for this sort of thing. Getting rid of that tracheotomy sequence would be a good place to start, but it would still leave a lot of mediocrity to contend with.