Method employing a supported metallocene catalyst composition in the production of an isotactic ethylene propylene co-polymer. The composition comprises a metallocene component supported on a particulate silica support having average particle size of 10-40 microns, a pore volume of 1.3-1.6 ml/g, a surface area of 200-400 m 2/g. An alkylalumoxane cocatalyst component is incorporated on the support. The isospecific metallocene is characterized by the formula: B(CpRaRb)(FlR′2)MQn   (1) or by the formula: B′(Cp′R′aR′b)(Fl′)M′Q′n′   (2) In the formulas Cp and Cp′ are substituted cyclopentadienyl groups, Fl and Fl′ are fluorenyl groups, and B and B′ are structural bridges. R′ are substituents at the 2 and 7 positions, Ra and R′a are substituents distal to the bridge, and Rb and R′b are proximal to the bridge. M and M′ are transition metals, Q′ is a halogen or a C1-C4 alkyl group; and n′ is an integer of from 0-4.