United Defense Mfg Corp’s S7-DGIS is a variant of the M110- SASS, Semi-Automatic Sniper System precision rifles chambered in the time-tested 7.62 NATO round (7.62 x 51mm) and designed to hit point targets up to 800 meters (MER) and area targets up to one kilometer. The S7 takes after the M110 battle rifle designed by Eugene Stoner. The DGIS is a simple design that uses the hot gases coming from the gas port of the barrel and through a gas tube the hot gases are rammed into the bolt carrier group to cycle the round. The S7-DGIS uses a one piece KeyMod picatinny rail handguard held securely only at the barrel extension which allows the barrel to “float” and preserve barrel harmonics while in battery. This allows for greater accuracy and consistency. As designed, the barrel does not touch any part of the entire length of the handguard except at the barrel extension. The barrel comes in different lengths: 14.5, 16, 18, 20, 22.5, 24 and 25 inches with a choice of either fixed or retractable buttstock.