The Winchester USA Target Rifle Ammunition is the perfect choice for any shooter looking for a reliable, accurate, and powerful round for their target shooting needs. The Winchester USA Target Rifle Ammo features a full metal jacket bullet that is designed to deliver superior accuracy and performance. Plus, this ammo provides reduced barrel fouling for less cleaning and more time at the range. Please Note: While the 5.56x45mm will fit in a.223 Remington chamber, the 5.56 is a military round that runs at higher pressures than its.223 counterpart and is not recommended to be fired in a.223 Remington Chamber. This is military-grade ammunition. It may show discoloration which is caused by a process known as annealing. This is completely normal.