A two-part curable liquid silicone rubber composition comprises a first liquid composition and a second liquid composition. The first and second liquid compositions are stored separately and yield, upon mixing, a silicone rubber forming composition. The silicone rubber composition comprises: (A) an alkenyl group-containing organopolysiloxane comprising (A-1) an organopolysiloxane having only a silicon-bonded alkenyl group at each molecular terminal and (A-2) an organopolysiloxane having from 1 to 4 silicon-bonded alkenyl groups in side molecular chains and containing not greater than 2.0 wt. % of alkenyl groups; (B) a calcium carbonate powder; (C) a hydrosilylation reaction catalyst; and (D) an organohydrogenpolysiloxane having silicon-bonded hydrogen atoms.