Metallic cases stretch as a result of both the firing process and the subsequent resizing process.
When your cases reach a certain dimension, the original case length must be restored through trimming. These E-ZEE TRIM pilots are calibre specific case length guides for use with the Lyman E-ZEE TRIM hand case trimmer.
Each pilot is calibre specific so no measuring is required when setting up the E-ZEE TRIM. Just install the proper pilot and the case length is preset.