Product Description Winchester Ammo component bullets are custom-designed and manufactured to precise specifications to deliver consistent on-target performance. This Centerfire Rifle reloading bullet is a 5.56x45mm NATO/.224 diameter, 55 grain Full Metal Jacket Boat Tail (FMJBT) projectile intended for building reliable target and training loads. Packaged in a 500-count box (4 boxes per case), these bullets are built with a copper jacket over a lead core for dependable function and repeatable accuracy. Product Highlights 55 grain Full Metal Jacket Boat Tail (FMJBT) design for consistent range and practice performance .224" bullet diameter for 5.56x45mm NATO / .223 Remington applications Copper jacket with lead core for proven reliability and uniformity Bulk 500-count box (4 boxes per case) for high-volume reloading Precision-manufactured Winchester component bullets for repeatable on-target results Specs Brand: Winchester Ammo Manufacturer Part Number: WB556MC55D UPC: 020892642256 Product Type: Reloading rifle bullets (component projectiles) Caliber: 5.56x45mm NATO / .223 Remington Bullet Diameter: .224 Bullet Weight: 55 grain Bullet Type: Full Metal Jacket Boat Tail (FMJBT) Jacket Material: Copper Core Material: Lead Cannelure: No Rounds per Box: 500 Boxes per Case: 4 Approx. Package Dimensions (L x W x H): 5.3 x 3.8 x 3.1 in Approx. Package Weight: 4.125 lb Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer.