Load Specifications
Load data in caliber .458 SOCOM with .458 | 300gr | Lehigh Defense Controlled Fracturing bullet and 5 powders. The key underlying parameters are shown in the table above.
Important Notice: DO NOT go below Minimum Charge or above Maximum Charge. Since we have no control over the equipment and components used, any responsibility and liability for the results achieved is rejected.
Only powders/loads that match the current filter criteria are displayed: max pressure of a load ≤ 90% of max. standardized pressure, fill rate ≥ 80% and propellant combustion ≥ 95%. Use the sliders above the tables to adjust these thresholds.
Charge: Powder weight in grains. Start with the minimum load and work up carefully.
FR (Fill Rate): Case fill as a percentage. Values above 100% mean compressed loads.
MaxP / %: Maximum chamber pressure in bar and as a percentage of the standardized maximum for this caliber.
V(0): Muzzle velocity in feet per second (fps) at the standardized barrel length.
z (Powder Burn): Estimated propellant combustion percentage at bullet exit.
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Max Load - Barrel Length: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Hodgdon LilGun | <<locked>> | 84% | 30,879 psi | 88% | 1814 fps | 99.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 23,757 psi | 68% | 1129 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 22,568 psi | 64% | 1152 fps | 100% |
| SNPE Vectan BA6 1/2ᴾ | <<locked>> | 100% | 30,835 psi | 88% | 1693 fps | 99.6% |
| Vihtavuori N110 | <<locked>> | 92% | 30,995 psi | 89% | 1736 fps | 98.6% |
Start Load - Barrel Length: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Hodgdon LilGun | <<locked>> | 80% | 26,847 psi | 77% | 1739 fps | 98% |
| Hodgdon TrailBoss | <<locked>> | 80% | 16,868 psi | 48% | 1001 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 16,172 psi | 46% | 1024 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 19,102 psi | 55% | 1444 fps | 95.4% |
| Vihtavuori N110 | <<locked>> | 80% | 21,640 psi | 62% | 1545 fps | 95% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 5 powders for .458 SOCOM loaded with the .458 | 300gr | Lehigh Defense Controlled Fracturing. Hodgdon LilGun delivers the highest muzzle velocity at 1,814 fps; across all powders the maximum-charge window runs from 1,129 fps to 1,814 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 5 of the 5 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (241 MPa), the top charges use 64–89 %, leaving at least 11 % headroom. Hodgdon TrailBoss, ReloadSwiss RS 14, SNPE Vectan BA6 1/2 reach 100 % fill or more at maximum charge, so these are compressed loads: they need a long drop tube to seat cleanly and react sensitively to the case capacity of your own brass lot. Hodgdon TrailBoss, ReloadSwiss RS 14 stay subsonic at start load. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.