Many reloaders consider Lyman’s Neck Expanding (M) Die a valuable tool for improving the accuracy of their reloads. The die’s expander plug has two steps. The first step expands the inside of the case neck to just under bullet diameter for precise case neck tension in the finished reload. The second step expands the case mouth to bullet diameter or slightly over. This allows the jacketed or cast bullet to be started perfectly centered in the case mouth and properly aligned with the axis of the case neck. (By adjusting the neck expanding plug slightly deeper, Step 2 also provides a slight flaring of the case mouth for reloaders using cast bullets.)
