Load Specifications
Load data in caliber .458 SOCOM with .458 | 405gr | ACME RNFP COATED BLACK bullet and 6 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N120, ReloadSwiss RS 14 and Hodgdon TrailBoss.
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 |
|---|---|---|---|---|---|---|
| ADI AR 2207 | <<locked>> | 92% | 31,328 psi | 90% | 1637 fps | 97.3% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 27,630 psi | 79% | 1047 fps | 100% |
| Lovex S053 | <<locked>> | 84% | 31,256 psi | 89% | 1565 fps | 98.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 26,803 psi | 77% | 1070 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 86% | 31,328 psi | 90% | 1499 fps | 100% |
| Vihtavuori N120 | <<locked>> | 90% | 29,994 psi | 86% | 1591 fps | 98% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2207 | <<locked>> | 86% | 26,020 psi | 74% | 1539 fps | 95.2% |
| Hodgdon TrailBoss | 11.7 gr | 80% | 19,899 psi | 57% | 932 fps | 100% |
| Lovex S053 | <<locked>> | 80% | 27,543 psi | 79% | 1503 fps | 97.9% |
| ReloadSwiss RS 14 | 11.9 gr | 80% | 19,189 psi | 55% | 951 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 26,455 psi | 76% | 1427 fps | 100% |
| Vihtavuori N120 | 33.2 gr | 82% | 23,482 psi | 67% | 1467 fps | 95.2% |
Recommended = one of the top powders for this cartridge and bullet combination.
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 14 powders for .458 SOCOM loaded with the .458 | 405gr | ACME RNFP COATED BLACK. Norma 200 delivers the highest muzzle velocity at 1,654 fps; across all powders the maximum-charge window runs from 1,047 fps to 1,654 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 14 of the 14 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (241 MPa), the top charges use 77–90 %, leaving at least 10 % headroom. 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. Vihtavuori N120, ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for .458 SOCOM with the .458 | 405gr | ACME RNFP COATED BLACK they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 1680, Alliant Reloder-10x, Alliant Reloder-7 burn incompletely and react more sensitively to barrel length and temperature. 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.