Stupid scored big with an estimated $50 million opening weekend for Jackass 3D, Johnny Knoxville’s third foray into theaters. The film, which lured in 15 percent more women than Jackass 2, may break the record for highest-grossing October opening of all time, if projections hold. The R-rated laugh fest will surpass Scary Movie 3, which earned $48 million back in 2003, and a single-day opening record of $21.8 million for its opening day Friday. The film scored well with audiences, mostly young males, earning a B+ from exit pollster CinemaScore.