Load Specifications
Load data in caliber .357 Auto Mag. with .357 | 125gr | Speer JHP bullet and 38 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N32C Tin Star, 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 ≥ 60% and propellant combustion ≥ 80%. 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: 6.5"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate Solo 1000² | <<locked>> | 64% | 32,503 psi | 88% | 1450 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 68% | 33,141 psi | 90% | 1522 fps | 100% |
| Accurate TCM*² | <<locked>> | 68% | 29,892 psi | 81% | 1660 fps | 88.7% |
| ADI AP 100 | <<locked>> | 80% | 31,981 psi | 86% | 1657 fps | 99.5% |
| ADI APS 350² | <<locked>> | 64% | 32,866 psi | 89% | 1348 fps | 100% |
| ADI APS 450² | <<locked>> | 64% | 32,213 psi | 87% | 1368 fps | 100% |
| ADI AS 30² | <<locked>> | 64% | 32,155 psi | 87% | 1411 fps | 100% |
| Alliant BE-86² | <<locked>> | 64% | 30,966 psi | 84% | 1470 fps | 100% |
| Alliant BLUE DOT* | <<locked>> | 80% | 31,067 psi | 84% | 1686 fps | 92.4% |
| Alliant Green Dot² | <<locked>> | 64% | 32,416 psi | 88% | 1467 fps | 100% |
| Alliant Herco | <<locked>> | 80% | 33,025 psi | 89% | 1594 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 64% | 30,501 psi | 82% | 1670 fps | 98.8% |
| Alliant RED DOT² | <<locked>> | 64% | 31,270 psi | 85% | 1417 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 64% | 30,560 psi | 83% | 1562 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 32,401 psi | 88% | 1453 fps | 100% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 80% | 32,256 psi | 87% | 1457 fps | 100% |
| Hodgdon Clays² | <<locked>> | 72% | 32,532 psi | 88% | 1375 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 21,248 psi | 57% | 1217 fps | 100% |
| Maxam CSB 1² | <<locked>> | 68% | 30,937 psi | 84% | 1483 fps | 100% |
| Maxam CSB 2² | <<locked>> | 64% | 31,285 psi | 85% | 1483 fps | 100% |
| Maxam CSB 3² | <<locked>> | 64% | 31,053 psi | 84% | 1457 fps | 100% |
| Maxam CSB 4² | <<locked>> | 64% | 32,764 psi | 89% | 1463 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 19,653 psi | 53% | 1224 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 68% | 32,909 psi | 89% | 1585 fps | 100% |
| ReloadSwiss RS 24² | <<locked>> | 68% | 32,053 psi | 87% | 1703 fps | 95.9% |
| Rottweil P 806² | <<locked>> | 68% | 29,356 psi | 79% | 1644 fps | 100% |
| SNPE Vectan A0² | <<locked>> | 68% | 31,227 psi | 84% | 1529 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 64% | 33,025 psi | 89% | 1526 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 72% | 31,227 psi | 84% | 1594 fps | 100% |
| SNPE Vectan BA9 1/2² | <<locked>> | 64% | 32,648 psi | 88% | 1522 fps | 100% |
| Somchem MS200² | <<locked>> | 64% | 31,111 psi | 84% | 1539 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 64% | 29,298 psi | 79% | 1578 fps | 100% |
| Vihtavuori 3N38 | <<locked>> | 80% | 32,880 psi | 89% | 1703 fps | 96.8% |
| Vihtavuori N105 | <<locked>> | 80% | 29,631 psi | 80% | 1686 fps | 98.4% |
| Vihtavuori N32C Tin Star | <<locked>> | 92% | 32,938 psi | 89% | 1385 fps | 100% |
| Vihtavuori N340² | <<locked>> | 64% | 31,270 psi | 85% | 1542 fps | 100% |
| Vihtavuori N350² | <<locked>> | 72% | 32,314 psi | 87% | 1627 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 68% | 32,547 psi | 88% | 1529 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 6.5"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate Solo 1000² | <<locked>> | 60% | 29,225 psi | 79% | 1398 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 60% | 26,324 psi | 71% | 1411 fps | 100% |
| Accurate TCM*² | <<locked>> | 64% | 25,875 psi | 70% | 1568 fps | 85.9% |
| ADI AP 100*² | <<locked>> | 60% | 18,130 psi | 49% | 1329 fps | 93.2% |
| ADI APS 350² | <<locked>> | 60% | 29,979 psi | 81% | 1302 fps | 100% |
| ADI APS 450² | <<locked>> | 60% | 29,022 psi | 78% | 1319 fps | 100% |
| ADI AS 30² | <<locked>> | 60% | 28,848 psi | 78% | 1358 fps | 100% |
| Alliant BE-86² | <<locked>> | 60% | 27,282 psi | 74% | 1411 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 68% | 21,886 psi | 59% | 1467 fps | 85.8% |
| Alliant Green Dot² | <<locked>> | 60% | 29,182 psi | 79% | 1414 fps | 100% |
| Alliant Herco² | <<locked>> | 60% | 19,827 psi | 54% | 1332 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 60% | 27,006 psi | 73% | 1594 fps | 97.7% |
| Alliant RED DOT² | <<locked>> | 60% | 27,963 psi | 76% | 1362 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 27,209 psi | 74% | 1499 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 28,645 psi | 77% | 1394 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 19,319 psi | 52% | 1230 fps | 100% |
| Hodgdon Clays² | <<locked>> | 60% | 24,439 psi | 66% | 1237 fps | 100% |
| Hodgdon TrailBoss² | 5.4 gr | 60% | 9,790 psi | 26% | 915 fps | 100% |
| Maxam CSB 1² | <<locked>> | 60% | 25,164 psi | 68% | 1385 fps | 100% |
| Maxam CSB 2² | <<locked>> | 60% | 27,717 psi | 75% | 1421 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 27,949 psi | 76% | 1407 fps | 100% |
| Maxam CSB 4² | <<locked>> | 60% | 29,472 psi | 80% | 1411 fps | 100% |
| ReloadSwiss RS 14² | 5.5 gr | 60% | 9,253 psi | 25% | 919 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 25,991 psi | 70% | 1470 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 60% | 24,526 psi | 66% | 1535 fps | 91.7% |
| Rottweil P 806² | <<locked>> | 60% | 22,133 psi | 60% | 1490 fps | 99% |
| SNPE Vectan A0² | <<locked>> | 60% | 24,831 psi | 67% | 1414 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 60% | 29,631 psi | 80% | 1470 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 60% | 21,814 psi | 59% | 1401 fps | 99.2% |
| SNPE Vectan BA9 1/2² | <<locked>> | 60% | 29,124 psi | 79% | 1463 fps | 100% |
| Somchem MS200² | <<locked>> | 60% | 27,717 psi | 75% | 1480 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 60% | 25,918 psi | 70% | 1512 fps | 100% |
| Vihtavuori 3N38*² | <<locked>> | 60% | 17,738 psi | 48% | 1342 fps | 86.7% |
| Vihtavuori N105*² | <<locked>> | 60% | 14,866 psi | 40% | 1299 fps | 87.2% |
| Vihtavuori N32C Tin Star² | 7.3 gr | 60% | 16,491 psi | 45% | 1093 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 27,789 psi | 75% | 1483 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 22,684 psi | 61% | 1437 fps | 99.9% |
| Winchester AutoComp ² | <<locked>> | 60% | 25,976 psi | 70% | 1417 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
* not dangerous but load has suboptimal powder burnt with possible characteristics such as extensive muzzle flash or inaccurate loads.
² fill rate low - you might want to consider using a filler to ensure proper ignition.
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 38 powders for .357 Auto Mag. loaded with the .357 | 125gr | Speer JHP. ReloadSwiss RS 24 delivers the highest muzzle velocity at 1,703 fps; across all powders the maximum-charge window runs from 1,217 fps to 1,703 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 9 of the 38 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (255 MPa), the top charges use 53–90 %, 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 N32C Tin Star, ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for .357 Auto Mag. with the .357 | 125gr | Speer JHP they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate TCM, Alliant BLUE DOT burn incompletely and react more sensitively to barrel length and temperature. Hodgdon TrailBoss, ReloadSwiss RS 14, Vihtavuori N32C Tin Star 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.