308 Winchester Small Base Full Length X-2 Die Set by RCBS RELOADING PRODUCTSTrim the case once and never trim again! The X sizer die looks like a regular full length sizer die. Inside and the die features a specially designed mandrel with an expander ball and decapping pin attached. The mandrel is what the X die is all about. The patented X Sizer die eliminates the need for repeated trimming after an initial trim of 0.020" of the max case length to standardize the case. The X die doesn't shorten the length of the case; the mandrel reduces the growth rate as the case grows as a result of the case mouth contacting the mandrel during sizing. Comes with standard bullet seater die.