The Heat Sandra Bullock, Melissa McCarthy, Michael Rapaport. Directed by Paul Feig. Rated R. Opens Friday.

Buddy-cop movies succeed based on chemistry; the Lethal Weapon series made it to four installments thanks to the dynamic between Mel Gibson and Danny Glover, not because it was telling riveting crime stories. The Heat has that part down: Sandra Bullock and Melissa McCarthy make for a very entertaining mismatched pair as uptight FBI agent Sarah Ashburn and uncouth Boston police detective Shannon Mullins, respectively. Their character types are standard-issue, as is the plot that forces them to work together, going from antagonists to allies. Bullock’s character is a retread of her role in the Miss Congeniality movies, and McCarthy is doing a variation on her Bridesmaids and Identity Thief characters. But despite the lazy plotting and the inconsistent humor (Mullins’ family full of Boston stereotypes is particularly groan-worthy), Bullock and McCarthy have excellent rapport, and there are enough funny moments in their banter to make The Heat a worthy addition to the buddy-cop canon.