Lee Undersize Mandrel .222" - For Collet Sizing Dies

The Lee Undersize Mandrel .222" for Collet Sizing Dies is a precision reloading component designed for shooters and handloaders who demand tight tolerances and consistent case neck sizing. This mandrel is engineered specifically for use with Lee's collet sizing die system and serves a critical function in the reloading process—ensuring case necks are sized to exact specifications for improved accuracy and cartridge consistency. Whether you're a competitive precision rifle shooter, long-range hunter, or dedicated reloader, this undersize mandrel addresses the need for superior case preparation that factory ammunition cannot provide.

Manufactured by Lee Precision, this .222" mandrel works in conjunction with collet sizing dies to apply precise, uniform pressure to case necks during the sizing process. The undersize dimension ensures cases are brought to specification without excessive work that can cause case hardening or premature neck failure. The mandrel's compact design—measuring 3.3 inches in length with a 1.05 x 0.95 inch profile and weighing just 0.05 lbs—makes it an efficient addition to any reloading bench setup. The collet system itself provides superior sizing control compared to traditional full-length dies, offering handloaders the ability to size only the case neck while preserving case length and shoulder geometry for maximum case life and accuracy potential.

This mandrel is ideal for reloaders working with .222 Remington and related cartridges who prioritize precision and consistency across high-volume production runs. Installation is straightforward—the mandrel seats directly into the collet die assembly without requiring additional setup or adjustment beyond standard reloading press operation. Serious precision shooters will appreciate how the undersize dimension contributes to tighter velocity spreads and improved group consistency, particularly in rifles that demand match-grade ammunition. Compatibility is confirmed with Lee's collet sizing die platform, making this an essential component for any reloader committed to optimizing case preparation standards.