A conversion press comprising: an upper tooling assembly , a lower tooling assembly , and a transfer belt assembly , wherein said upper tooling assembly is structured to move between a first position, wherein said upper tooling assembly is spaced from said lower tooling assembly , and a second position, wherein said upper tooling assembly is disposed a forming distance from said lower tooling assembly , said upper tooling assembly and said lower tooling assembly defining a plurality of end lanes and a tab lane , said end lanes extending generally parallel to each other, said tab lane extending generally perpendicular to said end lanes , said transfer belt assembly being structured to move a number of shells through each said end lane , said transfer belt assembly including a number of transfer belts , each transfer belt assembly transfer belt defining a number of columns of recesses , each recess corresponding to a shell , each transfer belt assembly transfer belt moving through an end lane , said tab lane having a width greater than the length of a 2X2 cluster of shell recesses ; and a retainer assembly , wherein the retainer assembly comprises: a retaining member assembly structured to selectively retain at least one shell in a transfer belt assembly belt column of recesses ; said retaining member assembly including a retaining member ; and characterized in that : the retaining member includes an elongated idle bar ; and said idle bar is structured to extend generally perpendicularly across at least one transfer belt assembly transfer belt ; with the retaining member assembly further comprising a motion assembly structured to move said retaining member between a first position, wherein said retaining member is spaced from said transfer belt assembly transfer belt , and a second position, wherein said retaining member is disposed a retaining distance from said transfer belt assembly transfer belt . a width greater than the length of a 2X2 cluster of shell recesses ; and a retainer assembly , wherein the retainer assembly comprises: a retaining member assembly structured to selectively retain at least one shell in a transfer belt assembly belt column of recesses ; said retaining member assembly including a retaining member ; and characterized in that : the retaining member includes an elongated idle bar ; and said idle bar is structured to extend generally perpendicularly across at least one transfer belt assembly transfer belt ; a retaining member assembly structured to selectively retain at least one shell in a transfer belt assembly belt column of recesses ; said retaining member assembly including a retaining member ; the retaining member includes an elongated idle bar ; and said idle bar is structured to extend generally perpendicularly across at least one transfer belt assembly transfer belt ; with the retaining member assembly further comprising a motion assembly structured to move said retaining member between a first position, wherein said retaining member is spaced from said transfer belt assembly transfer belt , and a second position, wherein said retaining member is disposed a retaining distance from said transfer belt assembly transfer belt . <EOS>