Winchester‘s USA line in 5.56x45mm (brand part no. WM193150) loads a 55-grain full metal jacket bullet, sold here by the full 600-round case for AR-platform shooters who train in real volume. USA is Winchester’s affordable, widely available range ammunition line, built around dependable feeding through semi-auto rifles rather than hunting-style expansion. The cartridge is marked for both 5.56x45mm NATO and .223 Remington chambers, giving it broad compatibility across AR-15-pattern rifles. At this case quantity, true cost works out to roughly 61 cents a round, meaningfully below what the same rounds would cost split across individual boxes. For 5.56/.223 shooters who burn through range ammo fast, this rifle ammunition case is built to keep up.

Key Specifications

• The chambering is 5.56x45mm NATO / .223 Remington, dimensionally compatible with either chamber.
• The bullet weighs 55 grains, a standard weight for the caliber.
• The bullet is a full metal jacket, built for reliable feeding rather than expansion.
• USA is Winchester’s affordable, widely available range ammunition line.
• True cost runs about $0.61 per round at this case quantity.
• The full case totals 600 rounds, packed as 4 boxes of 150.
• The shipping case measures roughly 15.7 inches long, worth knowing for storage planning.
• This is built for range and training use rather than hunting, since FMJ bullets aren’t built to expand.
• Buying a full case brings the true per-round cost well below single-box pricing.

Frequently Asked Questions

Will this run in a rifle chambered in .223 Remington? Yes, 5.56x45mm NATO and .223 Remington share chamber dimensions, and this load is marked for both.

Is this FMJ round good for hunting? No, full metal jacket bullets aren’t built to expand, so this load is best suited to range, training, and target use.

How much ammo comes in the full case? The case totals 600 rounds, packed as 4 boxes of 150.

Buy Winchester USA 5.56x45mm 55gr FMJ 600rd Case Lot

High-round-count AR training runs on cases, not boxes, and USA’s affordable FMJ keeps that math working. Order from our Lubbock, Texas gun shop and it ships fast to your door.