Premium Ultra Mag For Serious Hunters There's probably been more big game shot with Remington Core-Lokts than any other ammunition. For more than six decades, it has remained the leader in centerfire hunting ammunition. One of the first controlled-expansion bullet designs, it's still one of the most effective ever developed. Its progressively tapered copper jacket is locked to a solid lead core for perfectly controlled expansion and high weight retention. Mfg: Remington