SU-260/P

The SU-260/P, known as the Machine Gun Day Optic (MDO), is a part of the ACOG (Advanced Combat Optical Gunsight) family developed by Trijicon. This optic gained a reputation for ruggedness and reliability in the challenging environments of Iraq and Afghanistan. It is particularly noted for its magnification and bullet drop compensator reticle, which are crucial for long-range engagements. While the ACOG series, including the TA31RCO, was adopted by the U.S. Army in 2007 as a field carry optic, the SU-260/P (Trijicon TA648 6x48 ACOG) was specifically adopted the following year for its enhanced capabilities suited to machine gun applications

The horseshoe reticle is sighted for 5,56 round and hits center at 100m. The top of the vertical line is sighted for 25m and 300m. Greater distances can be read off the vertical line. The horizontal lines can be used to estimate distances and measure target sight. The separation between large lines is 10 mils, with the small lines denoting the 5 mil. 1 mil corresponds to 1 m spacing at a distance of 1 km. In the image below you can see a 1 m cube being sighted at 100 m being exactly 10 mils.