Hornady 546449 Custom Grade Series IV 2 Die Set for 375 Flanged Mag Nitro Express Includes Sizing SeaterHornady'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. Series IV is another tier of bottleneck rifle cartridges,