Lee Undersize Mandrel .241, 243 Winchester

The Lee Precision Undersize Mandrel, .241 inch (Lee part no. 90007), is a .002-inch undersize swap-in for Lee’s Collet Neck Sizing Die, sized for 243 Winchester, 6mm Creedmoor, and 6mm/244 Remington Magnum. Straight from the factory, Lee’s collet die grips the bullet with a light press fit that suits cases of average hardness; this mandrel gives you a noticeably tighter grip for brass that’s been worked, annealed inconsistently, or simply needs more neck tension to hold a bullet securely under recoil. Swap it in without buying a whole new die, available in our reloading equipment lineup.

Key Specifications

• Ships at a listed weight of about 1.6 oz, a light add-on to any die order.
• Ground to .241 inch, a .002-inch undersize compared to Lee’s standard factory Collet Die mandrel.
• Fits 243 Winchester, 6mm Creedmoor, and 6mm/244 Remington Magnum.
• Swaps directly into Lee’s Collet Neck Sizing Die in place of the factory mandrel — no new die required.
• Delivers a tighter press fit on the bullet than the factory mandrel, for handloaders who want more neck tension.
• Lets you fine-tune neck tension without buying a whole new sizing die.
• Covers every cartridge listed above because they share the same bullet/neck diameter.

Frequently Asked Questions

What does an undersize mandrel do? It swaps into Lee’s Collet Neck Sizing Die in place of the factory mandrel, giving the case neck a tighter, more consistent press fit on the bullet than the stock setup.

Which cartridges is the .241 mandrel sized for? It fits 243 Winchester, 6mm Creedmoor, and 6mm/244 Remington Magnum.

Buy the Lee Undersize Mandrel .241, 243 Winchester

Order it from our Lubbock, Texas gun shop for fast, reliable shipping. Every mandrel size is stocked alongside Lee’s Collet Neck Sizing Dies.