documentclass[twoside=false]{scrbook}

usepackage{blindtext}

% KOMAoptions{BCOR=0mm}
% KOMAoptions{DIV=calc}

begin{document}
    blinddocument
end{document}

documentclass[twoside=false]{scrbook}

usepackage{blindtext}

KOMAoptions{BCOR=0mm}
KOMAoptions{DIV=calc}

begin{document}
    blinddocument
end{document}