Forster .223 WIN Bushing Bump Neck Sizing Die brings you an advanced level of precision by allowing you to precisely control the amount of bullet tension in your reloaded cartridges. A one-step neck sizing reduction/shoulder bump operation keeps your case necks straighter. This die improves accuracy and prolongs case life because the body of your case maintains its fire-formed “glove” fit to your rifle’s chamber. At the same time it “bumps” the shoulder of the case to maintain excellent case neck concentricity. Best of all, it prevents overworking the neck and allows you to control the amount of neck tension for your bullet seating operation.