Improve the accuracy of both cast and jacketed bullet loads with this neck expander die from Lyman. This die does not stretch cases like standard expander button style dies do. Instead, it works in a two-step process. The first step expands the inside of the case neck to just under bullet diameter. The second step expands the case mouth to bullet diameter or slightly over so that the bullet can be started perfectly centered.

Fits:
.40 S&W, 10mm Auto