Load Specifications
Load data in caliber .458 SOCOM with .458 | 450gr | ACME RNFP COATED bullet and 8 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2207, Vihtavuori N120 and ReloadSwiss RS 14.
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% | 31,053 psi | 89% | 1509 fps | 97.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 27,441 psi | 78% | 955 fps | 100% |
| IMR 4227 | <<locked>> | 82% | 30,400 psi | 87% | 1424 fps | 96% |
| Lovex S053 | <<locked>> | 84% | 30,893 psi | 88% | 1440 fps | 99.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 26,716 psi | 76% | 978 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 84% | 30,574 psi | 87% | 1460 fps | 95.9% |
| SNPE Vectan BA6 1/2 | <<locked>> | 86% | 31,212 psi | 89% | 1378 fps | 100% |
| Vihtavuori N120 | <<locked>> | 92% | 31,618 psi | 90% | 1496 fps | 98.8% |
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 | 31.3 gr | 86% | 25,730 psi | 74% | 1421 fps | 95.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 19,783 psi | 57% | 850 fps | 100% |
| IMR 4227 | <<locked>> | 80% | 28,616 psi | 82% | 1394 fps | 95.3% |
| Lovex S053 | <<locked>> | 80% | 27,354 psi | 78% | 1385 fps | 98.3% |
| ReloadSwiss RS 14 | 10.7 gr | 80% | 19,131 psi | 55% | 869 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 82% | 28,848 psi | 82% | 1434 fps | 95.2% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 26,339 psi | 75% | 1312 fps | 100% |
| Vihtavuori N120 | 29.9 gr | 82% | 23,337 psi | 67% | 1355 fps | 95.8% |
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 | 450gr | ACME RNFP COATED. Norma 200 delivers the highest muzzle velocity at 1,526 fps; across all powders the maximum-charge window runs from 955 fps to 1,526 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 76–90 %, 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. ADI AR 2207, Vihtavuori N120, ReloadSwiss RS 14 rank at the top here: for .458 SOCOM with the .458 | 450gr | ACME RNFP COATED 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.