The .300 Norma Magnum has been a recurring theme on the channel lately. Following our complete custom rifle build, it’s time to move into the load development process. In this test, we pair Berger 245-grain Hybrid bullets with Peterson brass to see what this heavy-hitting ELR (Extreme Long Range) platform can do—taking it all the way out to a mile. 

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The Build and Components

• Action: BAT Hammerhead Long Action (featuring a slick 75-degree bolt throw).
• Barrel: Custom Rifle Barrels 31-inch finished barrel (1:8 twist).
• Chassis: Accuracy Solutions Baby Orca Chassis (features an integrated bipod extender and micro elevation control on the buttstock).
• Optic: Telson Targetmaster Victory 5-32×56 scope.
• Suppressor: Area 419 Maverick Gen 2 (run in the full-length capped configuration to tame the .300 Norma’s intense muzzle blast).
• Bipod: Accu-Tac.

Key Specs & Load Components:

• Berger 245-grain Hybrid bullets (G7 BC: 0.433).
• Peterson .300 Norma Mag new brass (bulk pack).
• Retumbo powder.

Assembly and Modifications

Gunsmithing Notes: For the foundation of this build, the 31-inch barrel was chambered, threaded, and mated to the BAT Hammerhead action. The barreled action was then seated into the Accuracy Solutions Baby Orca chassis, utilizing its angled bag rider for optimal tracking.

Equipment Used: The barrel threading and modification work utilized the Precision Matthews PM-1440GT-VS lathe, while the final rifle chassis assembly and component mounting were secured using an Arrow Products Rock Vise. On the reloading bench, we ran the Redding Ultramag Press using 1-inch dies (full-length sizer and micrometer seater), opting to prime directly on the press for this specific batch.

Field Testing and Recoil Analysis

Methodology: We utilized Paul Phillips’ ELR load development strategy: shoot 3-shot groups focusing on standard deviation (SD) and group size, then confirm dope at distance. Hodgdon’s load data topped out at 77.9 grains of Retumbo, but seeing absolutely no pressure signs on the Peterson brass, we tested 1-grain increments starting at 79 up to 83 grains.

Performance Data:

79.0 grains: 2,772 fps | SD: 10.2 | Group: 0.362″

80.0 grains: 2,807 fps | SD: 10.4 | Group: 0.837″

81.0 grains: 2,853 fps | SD: 14.2 | Group: 0.282″

82.0 grains: 2,868 fps | SD: 19.7 | Group: 0.245″

83.0 grains (The Winner): 2,913 fps | SD: 4.9 | Group: 0.374″ (0.357 MOA).

Pushing 2,913 fps at 60°F yielded no stiff bolt lift or flattened primers, hitting the sweet spot for velocity and single-digit SD.

Recoil Metrics & ELR Confirmation: The Accuracy Solutions chassis paired with the Area 419 Maverick Gen 2 made for a highly steady, pleasant shooting platform that efficiently mitigated the .300 Norma’s recoil. At the Ridgeline range, we confirmed dope at 706 yards (3.6 mil dial-up) and 1,390 yards (0.8 miles). Stretching it to a full 1,760 yards (1 mile), we dialed 14.0 mils of elevation and held 0.5 mils left for wind. The result was three consecutive center-punches on the rock target, holding an impressive 2-mil group with a .30 caliber.

Conclusion

Final Thoughts: Taking this .300 Norma Mag out to a mile genuinely felt like cheating. The combination of the BAT action, the stability of the Baby Orca chassis, the consistency of Peterson brass, and the heavy Berger 245s created an absolute hammer of a rifle. This setup is perfection for anyone looking to seriously get into Extreme Long Range shooting without fighting erratic velocities or punishing recoil.

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Thanks,
Gavin Gear