A propylene 1-hexene copolymer containing from about 5.5 to about 9.0% by weight, based upon the total weight of the copolymer, of 1-hexene derived units having: a) two melting temperature peaks in the DSC plot having a difference in height ranging from 0 to 5 mW; b) the higher melting temperature, measured by DSC, ranging from about 141.0° C. to about 151.0° C.; and c) Melt Flow Rate (MFR, measured according to ASTM D 1238, 230° C./2.16 kg) from about 3.5 to about 8.0 g/10 min.