The M110 is Knight’s Armament’s name for the Semi-Automatic Sniper System in service with the U.S. Army and Marines Corps. It’s pretty sweet.
It does have its shortcomings, though. It’s a hell of a range gun, and when it works in the field, it works very well. However, its tight tolerances combined with sandy field conditions have caused them to fail at an incredibly high rate. As it stands, the Army has cannibalized about half of their SASS rifles to keep the other half running.
They’re currently looking for a more compact, more reliable but just as accurate rifle (0.3 MOA!) to replace it. If they find their unicorn, the Army will call it the CSASS (Compact Sniper Rifle System).
That being said, as far as competition guns go, it’s a champ. The M110 and comercial SR-25 variants are considered service rifles and are a go for High Power Rifle competitions.