Load Specifications
Load data in caliber .357 Auto Mag. with .355 | 124gr | LOS FMJ RN 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% | 32,634 psi | 88% | 1437 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 68% | 33,286 psi | 90% | 1509 fps | 100% |
| Accurate TCM*² | <<locked>> | 68% | 29,733 psi | 80% | 1637 fps | 87.9% |
| ADI AP 100 | <<locked>> | 80% | 31,792 psi | 86% | 1634 fps | 99.3% |
| ADI APS 350² | <<locked>> | 64% | 33,127 psi | 90% | 1335 fps | 100% |
| ADI APS 450² | <<locked>> | 64% | 32,184 psi | 87% | 1355 fps | 100% |
| ADI AS 30² | <<locked>> | 64% | 32,416 psi | 88% | 1398 fps | 100% |
| Alliant BE-86² | <<locked>> | 64% | 31,183 psi | 84% | 1457 fps | 100% |
| Alliant BLUE DOT* | <<locked>> | 80% | 31,430 psi | 85% | 1677 fps | 92% |
| Alliant Green Dot² | <<locked>> | 64% | 32,938 psi | 89% | 1457 fps | 100% |
| Alliant Herco² | <<locked>> | 76% | 30,487 psi | 82% | 1535 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 64% | 30,589 psi | 83% | 1654 fps | 98.5% |
| Alliant RED DOT² | <<locked>> | 64% | 31,517 psi | 85% | 1401 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 64% | 30,632 psi | 83% | 1545 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 32,460 psi | 88% | 1437 fps | 100% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 80% | 32,764 psi | 89% | 1447 fps | 100% |
| Hodgdon Clays² | <<locked>> | 72% | 32,068 psi | 87% | 1348 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 22,046 psi | 60% | 1211 fps | 100% |
| Maxam CSB 1² | <<locked>> | 68% | 31,183 psi | 84% | 1470 fps | 100% |
| Maxam CSB 2² | <<locked>> | 64% | 31,908 psi | 86% | 1470 fps | 100% |
| Maxam CSB 3² | <<locked>> | 64% | 31,546 psi | 85% | 1450 fps | 100% |
| Maxam CSB 4² | <<locked>> | 64% | 33,141 psi | 90% | 1450 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 20,740 psi | 56% | 1224 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 68% | 32,924 psi | 89% | 1572 fps | 100% |
| ReloadSwiss RS 24² | <<locked>> | 68% | 31,908 psi | 86% | 1680 fps | 95.3% |
| Rottweil P 806² | <<locked>> | 68% | 30,197 psi | 82% | 1644 fps | 100% |
| SNPE Vectan A0² | <<locked>> | 68% | 31,067 psi | 84% | 1512 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 64% | 32,909 psi | 89% | 1509 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 72% | 31,024 psi | 84% | 1575 fps | 100% |
| SNPE Vectan BA9 1/2² | <<locked>> | 64% | 33,040 psi | 89% | 1509 fps | 100% |
| Somchem MS200² | <<locked>> | 64% | 31,502 psi | 85% | 1526 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 68% | 33,330 psi | 90% | 1631 fps | 100% |
| Vihtavuori 3N38 | <<locked>> | 80% | 32,982 psi | 89% | 1690 fps | 96.4% |
| Vihtavuori N105 | <<locked>> | 84% | 33,098 psi | 89% | 1739 fps | 99% |
| Vihtavuori N32C Tin Star | <<locked>> | 92% | 33,228 psi | 90% | 1368 fps | 100% |
| Vihtavuori N340² | <<locked>> | 64% | 31,285 psi | 85% | 1526 fps | 100% |
| Vihtavuori N350² | <<locked>> | 72% | 32,387 psi | 88% | 1611 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 68% | 33,054 psi | 89% | 1519 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% | 29,791 psi | 81% | 1391 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 60% | 26,832 psi | 73% | 1401 fps | 100% |
| Accurate TCM*² | <<locked>> | 64% | 26,107 psi | 71% | 1555 fps | 85.4% |
| ADI AP 100*² | <<locked>> | 60% | 18,826 psi | 51% | 1332 fps | 93.4% |
| ADI APS 350² | <<locked>> | 60% | 30,095 psi | 81% | 1286 fps | 100% |
| ADI APS 450² | <<locked>> | 60% | 29,370 psi | 79% | 1309 fps | 100% |
| ADI AS 30² | <<locked>> | 60% | 29,515 psi | 80% | 1352 fps | 100% |
| Alliant BE-86² | <<locked>> | 60% | 27,833 psi | 75% | 1404 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 68% | 22,452 psi | 61% | 1463 fps | 85.8% |
| Alliant Green Dot² | <<locked>> | 60% | 29,559 psi | 80% | 1401 fps | 100% |
| Alliant Herco² | <<locked>> | 60% | 20,523 psi | 55% | 1329 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 60% | 27,050 psi | 73% | 1575 fps | 97.3% |
| Alliant RED DOT² | <<locked>> | 60% | 28,601 psi | 77% | 1352 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 27,659 psi | 75% | 1490 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 29,138 psi | 79% | 1385 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 19,812 psi | 54% | 1220 fps | 100% |
| Hodgdon Clays² | <<locked>> | 60% | 24,700 psi | 67% | 1227 fps | 100% |
| Hodgdon TrailBoss² | 5 gr | 60% | 10,820 psi | 29% | 919 fps | 100% |
| Maxam CSB 1² | <<locked>> | 60% | 25,222 psi | 68% | 1365 fps | 100% |
| Maxam CSB 2² | <<locked>> | 60% | 28,674 psi | 78% | 1417 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 28,311 psi | 77% | 1394 fps | 100% |
| Maxam CSB 4² | <<locked>> | 60% | 29,704 psi | 80% | 1398 fps | 100% |
| ReloadSwiss RS 14² | 5.1 gr | 60% | 10,443 psi | 28% | 928 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 26,353 psi | 71% | 1460 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 60% | 25,063 psi | 68% | 1532 fps | 91.6% |
| Rottweil P 806² | <<locked>> | 60% | 23,206 psi | 63% | 1496 fps | 99.2% |
| SNPE Vectan A0² | <<locked>> | 60% | 25,396 psi | 69% | 1411 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 60% | 29,370 psi | 79% | 1450 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 60% | 22,191 psi | 60% | 1391 fps | 99.1% |
| SNPE Vectan BA9 1/2² | <<locked>> | 60% | 29,370 psi | 79% | 1450 fps | 100% |
| Somchem MS200² | <<locked>> | 60% | 27,978 psi | 76% | 1463 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 60% | 26,426 psi | 71% | 1506 fps | 100% |
| Vihtavuori 3N38*² | <<locked>> | 60% | 18,405 psi | 50% | 1342 fps | 87% |
| Vihtavuori N105*² | <<locked>> | 60% | 15,896 psi | 43% | 1316 fps | 88.4% |
| Vihtavuori N32C Tin Star² | 6.8 gr | 60% | 17,477 psi | 47% | 1089 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 27,717 psi | 75% | 1463 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 22,989 psi | 62% | 1427 fps | 99.8% |
| Winchester AutoComp ² | <<locked>> | 60% | 26,716 psi | 72% | 1411 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 .355 | 124gr | LOS FMJ RN. Vihtavuori N105 delivers the highest muzzle velocity at 1,739 fps; across all powders the maximum-charge window runs from 1,211 fps to 1,739 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 8 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 56–90 %, 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 .355 | 124gr | LOS FMJ RN 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.