Load Specifications
Load data in caliber .458 SOCOM with .459 | 405gr | ACME RNFP LUBED bullet and 6 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 |
|---|---|---|---|---|---|---|
| ADI AR 2207 | <<locked>> | 94% | 30,922 psi | 88% | 1604 fps | 96.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 26,876 psi | 77% | 1020 fps | 100% |
| Lovex S053 | <<locked>> | 86% | 31,140 psi | 89% | 1542 fps | 98.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 26,049 psi | 74% | 1043 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 88% | 31,183 psi | 89% | 1476 fps | 100% |
| Vihtavuori N120 | <<locked>> | 94% | 31,517 psi | 90% | 1591 fps | 97.9% |
Start Load - Barrel Length: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2207 | <<locked>> | 90% | 27,354 psi | 78% | 1542 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 19,319 psi | 55% | 909 fps | 100% |
| Lovex S053 | <<locked>> | 80% | 25,875 psi | 74% | 1450 fps | 96.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 18,623 psi | 53% | 925 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 24,743 psi | 71% | 1378 fps | 100% |
| Vihtavuori N120 | <<locked>> | 86% | 24,772 psi | 71% | 1470 fps | 95.2% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 6 powders for .458 SOCOM loaded with the .459 | 405gr | ACME RNFP LUBED. ADI AR 2207 delivers the highest muzzle velocity at 1,604 fps; across all powders the maximum-charge window runs from 1,020 fps to 1,604 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 6 of the 6 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (241 MPa), the top charges use 74–90 %, 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. 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.