The COEI / BII Listings and Component Hand Receipts on ArmyProperty.com are valid for the M16A2 rifle, which is a product improvement of the M16A1 rifle and entered service in 1983. The major changes are:

• a heavier, stiffer barrel than the barrel of the M16A1;
• a redesigned handguard, using two identical halves, with a round contour which is sturdier and provides a better grip when holding the rifle;
• a new buttstock and pistol grip made of a tougher injection moldable plastic that provides much greater resistance to breakage;
• an improved rear sight which can be easily adjusted for windage and range;
• a modified upper receiver design to deflect ejected cartridges, and preclude the possibility of the ejected cartridges hitting the face of a left-handed firer;
• a burst control device, that limits the number of rounds fired in the automatic mode to three per trigger pull, which increases accuracy while reducing ammunition expenditure;
• a muzzle compensator, designed to reduce position disclosure and improve controllability and accuracy in both burst and rapid semi-automatic fire;
• a heavier barrel with a 1 in 7 twist to fire NATO standard SS 109 type (M855) ammunition which is also fired from the M249 Squad Automatic Weapon (SAW). This further increases the effective range and penetration of the rifle cartridge. The M16A2 will also shoot the older M193 ammunition designed for a 1 in 12 twist.