Download video: Lego Barrett M98B (working) + instruction
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Initializing link download.....
LDD file http://www.mediafire.com/download/7jmh71n16i5b77r/m98b_by_bear(LDD)_completed.lxf
Here it is. I spent for about 70 hours on it (building time). maximum range is near 12 meters. correction is for about 25 centimeter on 9 meters.