The Sniper Rifle System 99 Anti-Matériel was used by the UNSC Army during the Fall of Reach.
This MOC is not 100% LEGO; a dowel rod for supporting the barrel and custom waterslide decals were used. Overall length is 5'3" (1.60m) approximately. And it is very heavy.
Working features: Sliding bolt, removable magazine, and a trigger that can be pulled.