Winchester Ammunition .223 Remington Features In 1873 less than a decade after the Civil War and when Westward expansion was in full gallop Winchester introduced the first successful centerfire cartridges. Winchester has set the world standard in superior ammunition performance and innovation for more than a century. USA centerfire rifle ammo is the ideal choice for training or extended sessions at the range and provides several features such as no expansion positive functioning good accuracy and no barrel leading. Winchester Ammunition .223 Remington Specifications Brand: Winchester Ammo Category: Centerfire Rifle Rounds Series: Target Caliber: 223 Rem Model: USA Rounds Per Box: 20 Casing Material: Brass Muzzle Energy: 1323 ft lbs Muzzle Velocity: 3100 fps Application: Plinking Boxes Per Case: 50 Bullet Type: Full Metal Jacket (FMJ) Bullet Weight: 62 gr