Organopolysiloxane mixtures curable by hydrosilylation include MT organopolysiloxanes having 10 to 20 siloxy units and containing a fraction of 0.15 to 0.24 M units based on total siloxy units in the organopolysiloxane, and a polydispersity of 1.05 to 1.40, a hydrosilylation catalyst, and an Si—H-functional organopolysiloxane are curable to vulcanizates with elastic moduli which may be greater than 0.5 GPa.