Small for .175" primers. Primer Pocket Cleaners help ensure consistent ignition and reduce the incidence of misfires by removing powder and primer residue from the primer pockets of your cases. This simple tool is easy to use: Just hold the case mouth over the Primer Pocket Center with one hand while you quickly and easily clean the primer pockets by turning the Case Trimmer handle. There's no tightening or loosening of collets required. Will not remove brass from the webs of your cases.