NEW LEFT AND RIGHT  BOLT RAILS FOR BUILDING A M249, MK46 OR MK48 INTO A FULL AUTO OR SEMI AUTO. ONE PAIR (2) BOLT RAILS.  THESE ARE THE BEST RAILS AVAILABLE. HIGH QUALITY STEEL WITH THE REAR STOCK MOUNT, EJECTION PORT DOOR AXIS PIN AND EJECTOR AXIS PIN HOLES ALREADY DRILLED IN THE CORRECT POSITIONS. EASIEST RAILS TO INSTALL AND THE BEST QUALITY.  G I MILSPEC PARTS DROP RIGHT ONTO THESE RAILS WITH NO MODIFICATIONS, EASY ASSEMBLY. THESE ARE THE RAILS WE USE ON OUR MILITARY GRADE MACHINE GUNS.