Case Trimming
A collection page of Magnum Sports
About
Case trimmers and preparation tools for handloaders, from Hornady, RCBS, Lyman, Forster, Wilson and Lee. Cases stretch every time they are fired and resized. Once they grow past maximum case length the neck can pinch the projectile at the throat and spike pressure, so trimming is a safety job before it is an accuracy job. Trim to length, then chamfer and deburr the case mouth so the projectile seats straight without shaving jacket material. Beyond the basics, uniforming primer pockets and deburring flash holes removes some of the variation in ignition, and neck turning brings neck wall thickness into line for shooters chasing the last of the consistency in a match rifle. Manual trimmers are fine for modest volumes; a power or lathe-style trimmer earns its keep once you are doing hundreds of cases at a sitting.