RCBS MatchMaster Case Trimmer Collet #3 .440/.545

Collet #3 for the RCBS MatchMaster Precision Case Trimmer. It clamps case heads in the .356, .440 and .545 diameter range, which covers a long list of cartridges including 6mm PPC, 6mm Krag, 6.5 PRC, 300 WSM, 300 SAUM and 300 Remington Ultra Magnum.

The collet is what decides whether a trim is repeatable. If the case is not held square and tight, the trimmer chases whatever runout is in the brass and every case comes out a little different. Matching the collet to the case head diameter is the difference between a batch that all measures the same and one that needs sorting afterward.