Made to SAAMI specifications from C4 carbide, these reamers are sure to last up to 4 times longer than standard tool steel reamers. Available in the most popular calibers, these reamers include a removable pilot for use with the GTR Chamber Flushing System (sold separately). A roughing reamer is used to make the initial cut in an unchambered barrel, while a finishing reamer is used for final cutting and headspacing. 3/8" square drive shank is for use with a tap wrench (not included).