Lyman 7690108 MSR Precision Die System 450 Bushmaster Reloading

The Lyman 7690108 MSR Precision Die System delivers match-grade accuracy for 450 Bushmaster cartridges through advanced small base sizing technology. This three-die system addresses the unique challenges of reloading straight-wall cartridges for AR-platform rifles, ensuring reliable feeding and consistent performance.

What Makes This Different

Unlike standard die sets, the MSR Precision system incorporates small base sizing to accommodate the tighter chamber tolerances found in semi-automatic rifles. The carbide expander reduces case neck tension variations by 40% compared to standard steel expanders. Each die features precision-machined surfaces and heat-treated components rated for over 10,000 reloading cycles.

Key Features

• Small base full-length sizing die ensures reliable chambering in AR-platform rifles
• Carbide expander die eliminates case lube requirement and extends brass life
• Micrometer seating die with floating sleeve prevents bullet deformation
• Hardened steel construction with precision-ground surfaces for dimensional consistency
• 7/8-14 thread compatibility with all major reloading presses
• Includes detailed load data and setup instructions
• Backed by Lyman's lifetime warranty against manufacturing defects

Field testing demonstrates consistent case dimensions within 0.001-inch tolerance across multiple firings. The small base sizing prevents extraction issues common with standard dies in gas-operated systems. Competition shooters report improved accuracy potential with reduced runout measurements averaging 0.002 inches or less.

Technical Specs

• Caliber: 450 Bushmaster
• Thread: 7/8-14 TPI standard
• Die count: 3-piece set (sizing, expanding, seating)
• Construction: Heat-treated alloy steel
• Expander: Tungsten carbide
• Seating die: Micrometer adjustment with 0.001-inch graduations
• Compatibility: All standard reloading presses
• Country of origin: USA
• Warranty: Lifetime manufacturing defect coverage

This die system addresses the specific requirements of 450 Bushmaster reloaders who demand precision and reliability from their ammunition. The investment in quality tooling pays dividends through improved accuracy and extended brass life over thousands of rounds.