Now you can precisely control headspace with the new Redding Competition Shellholders. Comes in five-piece sets, each shellholder is calibrated in .002 inches increments (+.002 inches, +.004 inches, +.006 inches, +.008 inches and +.010 inches) to allow for fine adjustments. The distinct black oxide finish ensures durability, while each shellholder is clearly marked to indicate the exact amount it will decrease case-to-chamber headspace. With this set, you can easily adjust the shoulder bump to tailor cases for your specific chamber, achieving a custom fit for optimal performance.