“Loaded Gun: Life, Death and Dickinson,” writer-director Jim Walpaw's idiosyncratic search for the essence of cryptic poet Emily Dickinson (1830-86), whose sometimes morbid work “still seems ahead of its time.” The reclusive Dickinson is not an easy subject for a standard documentary. “Nothing,” Wolpaw sighs, “was giving me a real sense of who this woman was.” So in addition to interviewing experts and filming “arty” establishing shots, he also got actresses to improvise as Dickinson. The results are hit or miss. Says one: “I consider death to be an orgasmic moment.”