Browning BXR Matrix Tip .300 Win Mag 155 Grain Centerfire Rifle Ammo is designed specifically for hunting medium-sized species of big game, including whitetail deer, mule deer, and pronghorn, as well as the lighter species of African antelope. BXR bullets employ a Matrix Tip made of copper and polymer, and a wide impact diameter where the tip meets the jacket; together, these initiate rapid expansion, expending maximum energy inside the target. The bullets come in weights which are a few grains heavier than standard ammunition, enhancing their aerodynamic profiles and ballistic coefficients to retain downrange velocity and flatten trajectory. Browning BXR Centerfire Rifle Ammo comes loaded in nickel-plated, brass cases, an especially worthwhile feature to prevent corrosion when carrying ammo in cartridge loops on extended, hardcore hunting trips. Rapidly expanding bullets Copper/polymer Matrix Tip Enhanced aerodynamics Nickel-plated brass cases