Designed for use with the High Capacity Trimmer Collet #1 fits .50-70 Government .50-90-2 1/2-inch Sharps Straight .56-50 Spencer .470 Nitro Express 3 1/4-inch .500 Jeffery and .500 Nitro Express 3-inch; Collet #2 fits.338 Lapua .40-65 Shiloh Sharps .45-70 Government .45-90-2.4-inch Sharps Straight .45-100-2.6-inch Sharps Straight .45-110-2 7/8-inch Sharps Straight .45-120-3 1/4-inch Sharps Straight .404 Jeffery and.450 Rigby Rimless.