At the Range with my M1A2, I have targets slowly driving left and right at about 1500 yards. My Laser Finder is reading a good range at about 1800 yards. When I shoot, my HEAT rounds are splashing at about 1000 yards. Well short of the target. Is the Laser finder not feeding into the computer? Is there something about the HEAT round that I need to change to get an accurate firing solution?