Lyman's MSR Die Sets are engineered specifically for MSR ammo and are a must for anyone reloading for a modern sporting rifle. These sets include a Small Base Sizing Die designed for semi-auto use which will size cases to a slightly smaller diameter to ensure smooth chambering. Each die set comes with a separate Seating Die and Taper Crimp Die. The Taper Crimp Die is designed to give you added bullet grip for functioning through semi-auto actions. Straight walled cases come with Lyman's famous "M" Neck Expanding Die. The two step design of the expander plugs allow case mouths to be expanded just enough to smoothly seat a bullet without over working your brass. MSR Die Sets also come with one Lyman Ammo Checker gauge. These are "Go" gauges machined to minimum chamber specs. Simply drop your loaded round into the gauge, and if it fits, it will chamber. Naturally dies for "black rifles" should also be black, so MSR dies come with a black oxide ...