Redding Precision Expanding Mandrels (.338/8.6mm)

Redding Precision Expanding Mandrels (.338/8.6mm) let handloaders control case-neck I.D. and neck tension by sizing the inside of the case neck to a precise mandrel diameter.

• Machined on CNC lathes and heat-treated for dimensional integrity and long-term durability.
• Mandrels are machined from high-quality tool steel, then hardened and precision-ground to the final diameter (size marked on the head).
• Available in .0005" diameter increments ranging from .0005" through .0030" below nominal bullet diameter to fine-tune neck tension.
• Die body and mandrel have unique angled alignment surfaces for correct alignment when assembled and secured with the threaded retention plug and lock ring.
• Precision Expanding Die ships factory-assembled with one mandrel that is .0010" below nominal bullet diameter for each caliber (22–338); other mandrel sizes are available separately.

These mandrels provide a precise, adjustable method for setting neck tension and maintaining consistent inside neck dimensions when used with the matching Precision Expanding Die. The size-marked, precision-ground heads make selection and identification straightforward during reloading sessions.