Load Specifications
Load data in caliber .458 SOCOM with .458 | 400gr | Swift A-Frame 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.
A valid access license is required to use the Personalized Load Calculator.
You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2207 | <<locked>> | 92% | 30,574 psi | 87% | 1585 fps | 96% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 27,891 psi | 80% | 1024 fps | 100% |
| Lovex S053 | <<locked>> | 84% | 30,530 psi | 87% | 1519 fps | 98% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 27,021 psi | 77% | 1043 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 86% | 30,661 psi | 88% | 1460 fps | 100% |
| Vihtavuori N120 | <<locked>> | 92% | 31,111 psi | 89% | 1572 fps | 97.4% |
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>> | 90% | 28,703 psi | 82% | 1552 fps | 95.2% |
| Hodgdon TrailBoss | 10.7 gr | 80% | 20,262 psi | 58% | 909 fps | 100% |
| Lovex S053 | <<locked>> | 80% | 27,267 psi | 78% | 1463 fps | 96.9% |
| ReloadSwiss RS 14 | 10.9 gr | 80% | 19,769 psi | 56% | 932 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 26,208 psi | 75% | 1391 fps | 100% |
| Vihtavuori N120 | 31.9 gr | 86% | 26,063 psi | 74% | 1480 fps | 95.3% |
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 12 powders for .458 SOCOM loaded with the .458 | 400gr | Swift A-Frame. Alliant Reloder-10x delivers the highest muzzle velocity at 1,608 fps; across all powders the maximum-charge window runs from 1,024 fps to 1,608 fps. Alliant Reloder-10x 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 77–90 %, leaving at least 10 % headroom. Alliant Reloder-10x, 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 | 400gr | Swift A-Frame they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Reloder-10x, Alliant Reloder-7, IMR 4198 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.