United States Marines Antiterrorism ForceSpecial weapons and tactics of this new elite brigade BY SCOTT R. GOURLEY Carefully adjusting the variable scope on top of the new sniper rifle, a unit marksman squinted toward the far end of the training site where a fellow Marine was removing his chemical protection mask. "This is sweet," he chuckled. "I can look down his ear canal with this thing." The next person whose ear comes in the crosshairs of the enhanced Designated Marksman Rifle (DMR) will get more than an impromptu earwax inspection. Already field-tested in Afghanistan, the DMR version of the 7.62mm...