Provided are ethylene propylene copolymers compositions thereof and methods for making the same. The composition may include an ethylene copolymer, comprising 40 wt % to 70 wt % of units derived from ethylene, and at least 30 wt % of units derived from at least one α-olefin having 3 to 20 carbon atoms. The composition can have a melting point (Tm) in ° C., as measured by DSC, that satisfies the relation: Tm>3.4×E−180, where E is the weight % of units derived from ethylene in the copolymer. The composition can also have a Mw/Mn ratio of about 1.5 to about 3.5. The composition can further have a content of Group 4 metals derived from a catalyst of 25 ppm or less.