The Hornady Lock-N-Load Handgun Metering Assembly is the perfect tool for the reloader looking to improve the function of their Hornady Lock-N-Load Powder Measure. The Handgun Metering Assembly features an adjustment lock ring, which allows settings to be locked in place permanently for a favorite load. The assembly is designed to throw charges of pistol powders between 0.5 to 17 grains. Notes: Must be used with the handgun rotor, will not work with the Lock-N-Load Bench Rest or Black Powder Measurers