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.