Load Specifications
Load data in caliber .458 SOCOM with .458 | 350gr | H&N TC HS bullet and 12 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 TrailBossᴾ | <<locked>> | 100% | 25,556 psi | 73% | 1096 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 25,730 psi | 74% | 1096 fps | 100% |
| Lovex S053 | <<locked>> | 90% | 30,850 psi | 88% | 1663 fps | 96.8% |
| Lovex S053 | <<locked>> | 90% | 30,618 psi | 87% | 1657 fps | 96.7% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 24,627 psi | 70% | 1119 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 24,497 psi | 70% | 1115 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 92% | 30,966 psi | 88% | 1604 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 92% | 30,734 psi | 88% | 1601 fps | 100% |
| Vihtavuori N110 | <<locked>> | 84% | 30,632 psi | 88% | 1640 fps | 99.9% |
| Vihtavuori N110 | <<locked>> | 84% | 30,618 psi | 87% | 1637 fps | 99.9% |
| Vihtavuori N120 | <<locked>> | 98% | 31,140 psi | 89% | 1706 fps | 95.8% |
| Vihtavuori N120 | <<locked>> | 98% | 30,995 psi | 89% | 1703 fps | 95.7% |
Start Load - Barrel Length: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Hodgdon TrailBoss | <<locked>> | 80% | 18,347 psi | 52% | 974 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 18,217 psi | 52% | 971 fps | 100% |
| Lovex S053 | <<locked>> | 86% | 27,311 psi | 78% | 1598 fps | 95.4% |
| Lovex S053 | <<locked>> | 86% | 27,325 psi | 78% | 1594 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 17,550 psi | 50% | 994 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 17,434 psi | 50% | 991 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 22,060 psi | 63% | 1447 fps | 99.4% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 21,843 psi | 62% | 1440 fps | 99.3% |
| Vihtavuori N110 | <<locked>> | 80% | 27,006 psi | 77% | 1578 fps | 99.5% |
| Vihtavuori N110 | <<locked>> | 80% | 26,992 psi | 77% | 1575 fps | 99.5% |
| Vihtavuori N120 | <<locked>> | 96% | 29,486 psi | 84% | 1677 fps | 95.1% |
| Vihtavuori N120 | <<locked>> | 96% | 29,341 psi | 84% | 1670 fps | 95% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 12 powders for .458 SOCOM loaded with the .458 | 350gr | H&N TC HS. Vihtavuori N120 delivers the highest muzzle velocity at 1,706 fps; across all powders the maximum-charge window runs from 1,096 fps to 1,706 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 12 of the 12 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (241 MPa), the top charges use 70–89 %, leaving at least 11 % headroom. Hodgdon TrailBoss, Hodgdon TrailBoss, ReloadSwiss RS 14 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, 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.