I would stay away from HP"S. Any good JSP or hardcast semi-wadcutter or flat nose will work (158 or 180 gr.) I use a 158 gr. SWC in my handloads and they work well. The only thing I would caution you about is keep the shots close, pretty much treat it like a bow.
"Suppose you were an idiot, and suppose you were a member of Congress, but I repeat myself." Mark Twain