Hornady's Custom-Grade Dies provide a lifetime of reloading. They are so well-crafted that they are guaranteed never to break or wear out from normal use. The Sip Spindle design features a series of light threads cut on the spindle and spindle collet. This design eliminates slippage and takes the knuckle-busting out of tightening the spindle lock while making spindle adjustments a snap.S eries IV is another tier of bottleneck rifle cartridges, obscure, and almost semi-custom. This 2-die set includes a sizer die and bullet seater die.