The Hornady Neck Turning Tool Mandrel (8mm / .323 Caliber) is a precision-machined, hardened steel reloading component engineered for the Hornady Lock-N-Load Neck Turn Tool chassis. Designed specifically for preparing 8mm cartridge brass, it threads directly into the tool's cutter head to provide rigid internal support along the inner neck wall. This internal piloting allows the external cutter to shave off high spots and uneven brass, producing uniform neck wall thickness, reducing bullet runout, and ensuring consistent neck tension for handloaded ammunition.

Key Features

• Internal Neck Alignment: Functions as a dedicated internal pilot to steady 8mm brass while the tool's cutter removes excess material.
• Concentricity Control: Eliminates thickness variations across case necks to promote uniform bullet release and reduce runout.
• Integrated Case Stop: Features an adjustable shoulder stop to precisely control the cut length and avoid cutting into the case neck-shoulder junction.
• Durable Construction: Precision-machined from hardened steel to resist wear and maintain structural consistency across repeated brass preparation cycles.
• Direct Chassis Integration: Specifically threaded to mate directly with the Hornady Lock-N-Load Neck Turn Tool cutter head.

Specifications

• Manufacturer Part Number (MPN): 391929
• Calibre: 8mm (.323" bullet diameter standard)
• Mandrel Pilot Diameter: 0.321" nominal specification
• Material: Hardened steel
• Weight: Approximately 0.045–0.05 kg (0.10 lbs packaged)
• Power Requirements: None (manual/benchtop mechanical operation)
• Tool Compatibility: Hornady Neck Turning Tool / Lock-N-Load Neck Turn Tool
• Cartridge Compatibility: 8mm cartridge cases, including 8x57mm IS (8mm Mauser) and 8mm Remington Magnum

Who is the Hornady Neck Turning Tool Mandrel (8mm) for?

• Precision Handloaders and Long-Range Hunters — Requires a dedicated 0.321" pilot diameter mandrel to support 8mm (.323" standard) case necks inside the Hornady Neck Turning Tool, eliminating wall-thickness variations for match-grade consistency downrange.
• Competitive Target Shooters — Delivers uniform neck tension on 8x57mm IS and 8mm Remington Magnum brass via a precision-machined steel neck turning mandrel weighing approximately 0.045–0.05 kg, preventing bullet runout during precision seatings.

Less suitable for: Reloading non-8mm calibres or handloaders using non-Hornady neck-turning chassis; brass with neck diameters smaller or larger than the nominal 0.321" pilot requires a calibre-specific mandrel sized to those alternative cartridge dimensions, while alternative brand platforms require chassis-matched turning pilots.