SIG Sauer Tango6T 1-6x24mm Review SIG Sauer Tango6T 1-6x24mm Review The United States Army has adopted the SIG Sauer Tango6T 1-6x24mm as its new dedicated optic for squad designated marksmen. Soldiers from the 1st Armored Brigade Combat Team (1ABCT), 3rd Infantry Division, conduct marksmanship training at the Fort Stewart, Georgia, sniper range on the U.S. Army’s new M110A1 Squad Designated Marksman Rifle (SDMR) on June 5, 2020. 1ABCT was the first unit in the Army to field this rifle. The SDMR fills the capability gap at the squad level. (U.S. Army, Sgt. Daniel Guerrero)