Well I don't think there is any way at all to level range in F2p without adding combat. XP lamps or books is the only thing I can think of but that would literally takes ages and isn't a realistic answer. If your willing to take the XP, I'd say get your range to 40 first. Then wearing your green d hide, iron plate, iron helm, iron shield do what I suggested in the earlier post. Once you finish with your magic go back and do the range to whatever you like.