The Redding .300 Remington Ultra Magnum Full Length 2-Die Set is precision-engineered from heat-treated alloy steel to resize fired brass cases back to SAAMI minimum factory dimensions and accurately seat bullets. Designed for large-capacity .300 RUM bottleneck cartridges, this 2-die system decaps spent primers, bumps the case shoulder, and resizes the entire body to ensure flawless feeding and chambering across multiple firings. Both dies feature standard knurled lock rings and interface with standard reloading presses via an industry-standard 7/8"-14 TPI thread pattern.

Key Features

• Full Length Sizing Die: Includes an integrated decapping rod assembly and expander ball to deprime spent brass, resize the entire cartridge case to factory tolerances, and reset the shoulder.
• Bullet Seating Die: Features a built-in crimp ring and standard seat plug to maintain consistent seating depth and concentricity for standard .308 in (7.82 mm) diameter projectiles.
• Alloy Steel Construction: Precision-machined, heat-treated steel bodies resist wear and withstand the high forming pressures required for magnum-sized cartridge brass.
• Universal Press Threading: Built with 7/8"-14 threads to mount directly into standard single-stage and turret reloading presses.

Specifications

• Calibre: .300 Remington Ultra Magnum (.300 RUM)
• Bullet Diameter Compatibility: .308 in (7.82 mm)
• Thread Interface: 7/8"-14 TPI
• Die Set Composition: Full Length Sizing Die, Bullet Seating Die
• Shellholder Required: Redding #6 (sold separately)
• Packaged Weight: ~0.6 kg (1.3 lbs)
• Operation: Manual / Mechanical

Who is the Redding .300 Remington Ultra Magnum Full Length Die Set for?

• Handloaders loading for .300 Remington Ultra Magnum bolt-action rifles — requires a 300 RUM full length die set machined with a 7/8"-14 TPI thread pattern to seat .308 in (7.82 mm) diameter bullets to uniform depths on standard reloading presses.
• Long-range hunters requiring reliable cartridge chambering across multiple firings — requires a dedicated .300 RUM full length sizing die in a 0.6 kg package to return large-capacity magnum brass back to factory SAAMI dimensions, preventing chamber binding in field conditions.

Less suitable for: Reloading presses lacking the vertical clearance and stroke to clear the over 3.60 in (91.4 mm) maximum overall cartridge length of the .300 RUM; compact or short-stroke single-stage presses should be upgraded to a tall-frame, magnum-capable reloading press.