Metallocene catalysts Et(Ind)(2)ZrCl2/MAO and Et(Ind)(2)HfCl2/MAO were used in ethene/propene copolymerization and in ethene/propene/5-ethylidene-2-norbornene (E/P/ENB) terpolymerization. The copolymerization activity of the Et(Ind)(2)ZrCl2/MAO system was 20 x 10(3) kg(polym)/mol(Mt)*h, the Et(Ind)(2)HfCl2/MAO yielding 5 x 10(3) kg(polym)/mol(Mt)*h. The polymerization activity decreased with diene addition, but this effect was significant only at very large diene feeds. The catalysts incorporated diene readily. Materials with an ethene content of 55 to 70 mol % and an ENB content of 2 to 16 mol % were produced. Et(Ind)(2)HfCl2 produced a considerably higher molar mass material than the Et(Ind)(2)ZrCl2 catalyst. The molar mass distributions were narrow. Copolymers and terpolymers with up to 3 mol % ENB content had some crystallinity. Copolymer T(g)s were between -59 degrees C and -55 degrees C. The terpolymer glass transition temperature rose 1.5 degrees C per wt % of ENB in the polymer. Polymer characteristics reported include composition, molar mass distribution, melt flow rate, density, and thermal behavior. The dynamic mechanical and rheological properties of the materials in comparison with commercial E/P/ENB terpolymers are discussed.