I don’t know about you, but I love watching car chases in movies set in the 1920s, because you know that despite sharp editing and camera angles giving the impression of astounding speed, those vehicles were probably scooting around at 40 miles per hour tops. Live by Night, director/writer/star Ben Affleck’s adaptation of Dennis Lehane’s 2012 novel, is similarly deceptive. Telling of a petty Boston crook who, between the ’20s and ’40s, becomes a Florida-based rum entrepreneur and bona-fide gangster, the film has a breadth and look and quality performers suggesting an epic tale of venality and greed, like The Godfather with fewer Sicilians and heavier humidity. In truth, however, it’s a dawdling, unsatisfying attempt at an epic, and it is slow. Forget 40 miles per hour; this thing doesn’t have a heart rate of even 40 beats per minute.