The Forster Inside Neck Reamer for .338 bullet diameter (.340-.3405) is a precision reloading tool designed to remove excess brass from case necks that can cause chamber pressure and accuracy issues.Forster Inside Neck Reamer - .338 Bullet Diameter (.340-.3405)Mounts in Case Trimmer for precise operationGrinds entire bullet diameter to precision for perfect symmetryMade from strong and durable steel constructionDesigned for unsized and untrimmed fired casesEliminates thick case necks that cause flyersEssential for serious reloaders working with .338 caliber cartridges this neck reamer ensures consistent case neck thickness for improved accuracy and proper chamber fit during reloading operations.