M855SS109
m855ss109 is a type of 5.56×45mm nato cartridge that features a ss109 projectile. it is also commonly referred to as m855 ammunition and was originally designed by belgian manufacturer fabrique nationale. this ammunition is widely used by military and law enforcement agencies around the world. the ss109 projectile consists of a 62-grain bullet with a steel core surrounded by a copper jacket, providing improved penetration capabilities compared to earlier ammunition types. it was designed to be fired from rifles with a 1:7 twist rate barrel, which helps stabilize the longer bullet. the m855ss109 cartridge achieves a muzzle velocity of approximately 3,050 feet per second when fired from a standard m16 rifle. this ammunition is notable for its ability to penetrate steel helmets and body armor at effective ranges. in the united states, m855 ammunition has been subject to various regulatory discussions due to its penetrating capabilities. the designation m855ss109 indicates that it meets both american m855 specifications and the ss109 standard used by nato countries.