RCBS Quick Change Powder Measure Large Metering Screw Assembly is a great powder measuring tool. Ideally designed for the reloader that has a variety of different cartridges and hates weighing charges every time they switch between the cartridges. These quick change parts can be used to update your existing RCBS Uniflow powder measures. A perfect match is with the RCBS Quick Change Powder Measure. Steel construction gives this the durability needed for reloading.