For SOS: put unit in editor and special weapons(NATO)>PREVIEW>pick the SOS from box>change zeroing to any desired value except 500m>switch to iron sight with CTRL+RMB>switch back to magnification> O.o
For DMS: put OPFOR marksman in editor>change zeroing to any desired value except 400m>switch to iron sight with CTRL+RMB>switch back to magnification> O.o