Bent over bb rows with an underhand grip, seated cable rows hit the rear delts, reverse pec deck flye hits them pretty good, and obviously bent over db rows, but honestly those hurt my delts more than anything else. I never do them for this reason. I have found that heavy pressing for bench and military, along with rows, and reverse pec deck, have actually made my delts over power my arms. I'm in the process of now bringing my arms up to match them.