Winchester USA Lake City .223 Rem 55 gr FMJ 200/ct is a high-volume target and training round manufactured by the Lake City Army Ammunition Plant for Winchester. Known for its consistent "White Box" performance, it is specifically designed for range practice and tactical exercises with AR-15 platform rifles. 
Product Highlights
Performance Metrics: Achieves a muzzle velocity of 3,240 fps and muzzle energy of 1,282 ft-lbs, providing a flat trajectory suitable for precision training.
Bullet Design: Features a 55-grain Full Metal Jacket (FMJ) projectile with a lead core and copper jacket, ensuring reliable feeding and reduced barrel fouling for extended range sessions.
Reloadable Components: Uses new, non-corrosive brass casings with Boxer primers, making the brass highly desirable for reloaders.
Range Compatibility: The non-magnetic projectile is generally compliant with indoor range restrictions that prohibit magnetic or "steel core" ammunition.