Redding Reloading Competition PR-50 Powder Measure. The engineering target range was approx. 50-60 grains with the ideal use range extending from approx. 35 to 75 grains. This powder measure uses all of the engineering features and knowledge gained from our other Competition powder measures. Specifications for Redding Reloading Competition PR: Manufacturer: Redding Reloading Quantity: 1 Package Contents: Redding Reloading Competition PR Redding Reloading 3900: Competition PR-50 Powder Measure