The Westford Board of Selectmen rejected a measure on Wednesday night to ban assault weapons in town. Selectmen voted 5 to 0 to remove the proposed ban from a Town Meeting warrant that is up for a vote next month, said Selectman Robert Jefferies, the vice chairman of the board who first suggested that the town craft a ban. He said selectmen removed the proposal after it attracted national attention, but the town still intends to “have a conversation and reach consensus” on weapons and how to secure them.