Lee Precision Decap Mandrel .3055 for 308 Winchester and 30-06

Lee Precision Decap Mandrel .3055" – 308 Winchester

The Lee Precision Decap Mandrel is the decapping spindle for Lee collet neck sizing dies: it is the element against which the collet fingers squeeze the case neck and, at the same time, it carries the pin that ejects the spent primer. This .3055" version is the one specified by Lee for 308 Winchester, 30-06 Springfield, 30-30 Winchester, 30-30 Ackley Improved, 300 Winchester Magnum, 300 WSM, 7.5x55 Swiss, 7.62x54R, 300 PRC, and it is replaced when the pin bends or the mandrel becomes worn.

In the collet die, the neck is not compressed by an external ring and then opened back up by an expander, as in full-length dies: four fingers squeeze it directly against the mandrel, so the diameter of the mandrel determines the final internal measurement of the neck. For this reason, Lee makes the mandrels .002" to .003" below the nominal bullet diameter: with a brass spring-back of .001"–.002", the finished neck remains about .001" below the bullet diameter, which is the correct tension to hold it. Lee describes this system as capable of producing a precisely aligned neck, reducing runout. The same .3055" diameter is also available under the code NS3548, though it is intended for 7.62x39, 300 AAC Blackout, and 300 HAM’R collet dies: the two mandrels belong to different die families.

Main features

• Lee designation: DECAP MANDREL .3055"
• Mandrel diameter: .3055"
• Lee design undersize: .002" to .003" below nominal bullet diameter
• Dual function: internal reference for neck sizing and decapping
• Quantity specified by Lee: 1 piece per die
• Calibers indicated by Lee: 308 Winchester, 30-06 Springfield, 30-30 Winchester, 30-30 Ackley Improved, 300 Winchester Magnum, 300 WSM, 7.5x55 Swiss, 7.62x54R, 300 PRC

Recommended use

Replacement part for Lee collet neck sizing dies — Collet Neck Sizing, Micrometer Neck Sizing, and Ultimate Die Set — in calibers 308 Winchester, 30-06 Springfield, 30-30 Winchester, 30-30 Ackley Improved, 300 Winchester Magnum, 300 WSM, 7.5x55 Swiss, 7.62x54R, 300 PRC. Lee classifies it among the spare parts for the 300 WSM Micrometer Neck Sizing Die Set and .30 caliber collet dies.

Package contents

The replacement part is supplied individually and includes only the decapping mandrel. The die body, collet assembly, and other die components are not included.

Manufacturer code: NS2627