Since 1939, more hunters have relied on Remington Core-Lokt than any other big game ammunition. Core-Lokt is the original controlled expansion bullet. Its time-proven performance has made it hunting's first choice for over 75 years. The tapered copper jacket is locked to a solid lead core delivering massive 2X expansion, weight retention, and consistent on-game results. Trust your next hunt to the best-selling hunting ammunition of all time.