5.56 NATO M855 62gr FMJ (Green Tip)

The M855 cartridge, commonly known as "green tip" due to its distinctive paint marking, has served as the standard 5.56x45mm NATO ball ammunition for the United States Military and NATO forces since approximately 1982. This ammunition features a 62-grain projectile with a boat tail design and a seven-grain steel "penetrator" tip designed to improve performance against intermediate barriers and light armor. The M855 was specifically engineered to enhance long-range performance in the Belgian Minimi and American M249 SAW, where the heavier bullet provides better terminal ballistics at extended ranges.

The steel penetrator core gives M855 its barrier-blind characteristics, enabling it to reliably pierce 0.12-inch thick steel well beyond 600 yards. This makes it particularly effective for tactical applications where shots may need to pass through car doors, windshields, or light building materials. However, this same penetrator design makes M855 somewhat less accurate than M193 at long range, as the steel core and lead core can separate slightly during flight, affecting consistency.

Available from numerous manufacturers including Winchester, IMI, Federal, and PMC, M855 delivers approximately 3,020-3,100 fps from a 20-inch barrel with muzzle energy around 1,289-1,323 ft-lbs. The ballistic coefficient of 0.304 provides adequate downrange performance, though not quite as flat-shooting as heavier match bullets. While an excellent general-purpose training and tactical round, M855 is less favored for precision shooting where its accuracy limitations become more apparent beyond 300 yards.