Load Specifications
Load data in caliber .357 Auto Mag. with .357 | 140gr | Speer JHP bullet and 37 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 No. 9*² | <<locked>> | 68% | 31,053 psi | 84% | 1594 fps | 89.9% |
| Accurate Solo 1250² | <<locked>> | 64% | 30,719 psi | 83% | 1385 fps | 100% |
| Accurate TCM*² | <<locked>> | 68% | 31,183 psi | 84% | 1591 fps | 91.2% |
| ADI AP 100 | <<locked>> | 80% | 33,141 psi | 90% | 1575 fps | 100% |
| ADI APS 450² | <<locked>> | 64% | 32,909 psi | 89% | 1286 fps | 100% |
| ADI AS 30² | <<locked>> | 64% | 32,982 psi | 89% | 1325 fps | 100% |
| Alliant BE-86² | <<locked>> | 64% | 31,676 psi | 86% | 1381 fps | 100% |
| Alliant BLUE DOT* | <<locked>> | 80% | 32,474 psi | 88% | 1614 fps | 94.6% |
| Alliant Green Dot² | <<locked>> | 64% | 32,938 psi | 89% | 1375 fps | 100% |
| Alliant Herco² | <<locked>> | 76% | 31,314 psi | 85% | 1463 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 64% | 31,879 psi | 86% | 1591 fps | 99.6% |
| Alliant RED DOT² | <<locked>> | 64% | 32,053 psi | 87% | 1332 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 64% | 31,198 psi | 84% | 1467 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 33,185 psi | 90% | 1365 fps | 100% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 80% | 33,170 psi | 90% | 1371 fps | 100% |
| Hodgdon Clays² | <<locked>> | 72% | 32,764 psi | 89% | 1283 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 21,553 psi | 58% | 1138 fps | 100% |
| Lovex D037.2*² | <<locked>> | 68% | 31,923 psi | 86% | 1611 fps | 90.3% |
| Maxam CSB 1² | <<locked>> | 68% | 31,923 psi | 86% | 1398 fps | 100% |
| Maxam CSB 2² | <<locked>> | 64% | 32,285 psi | 87% | 1391 fps | 100% |
| Maxam CSB 3² | <<locked>> | 64% | 31,720 psi | 86% | 1368 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 20,436 psi | 55% | 1155 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 64% | 30,647 psi | 83% | 1447 fps | 100% |
| ReloadSwiss RS 24² | <<locked>> | 68% | 33,214 psi | 90% | 1624 fps | 97.4% |
| Rottweil P 806² | <<locked>> | 68% | 30,603 psi | 83% | 1565 fps | 100% |
| Shooters World Heavy Pistol*² | <<locked>> | 68% | 31,923 psi | 86% | 1611 fps | 90.3% |
| SNPE Vectan A0² | <<locked>> | 68% | 31,966 psi | 86% | 1440 fps | 100% |
| SNPE Vectan BA6 1/2*ᴾ | <<locked>> | 100% | 27,035 psi | 73% | 1532 fps | 88% |
| SNPE Vectan BA7 1/2² | <<locked>> | 72% | 32,169 psi | 87% | 1509 fps | 100% |
| Somchem MS200² | <<locked>> | 64% | 32,198 psi | 87% | 1450 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 64% | 30,618 psi | 83% | 1499 fps | 100% |
| Vihtavuori 3N38² | <<locked>> | 76% | 30,574 psi | 83% | 1562 fps | 97.1% |
| Vihtavuori N105 | <<locked>> | 80% | 31,241 psi | 84% | 1617 fps | 99.5% |
| Vihtavuori N32C Tin Star | <<locked>> | 92% | 33,417 psi | 90% | 1296 fps | 100% |
| Vihtavuori N340² | <<locked>> | 64% | 32,024 psi | 87% | 1450 fps | 100% |
| Vihtavuori N350² | <<locked>> | 68% | 30,211 psi | 82% | 1486 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 64% | 30,139 psi | 81% | 1391 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 No. 9*² | <<locked>> | 64% | 26,789 psi | 72% | 1506 fps | 87.1% |
| Accurate Solo 1250² | <<locked>> | 60% | 27,427 psi | 74% | 1332 fps | 100% |
| Accurate TCM*² | <<locked>> | 60% | 23,308 psi | 63% | 1421 fps | 85.8% |
| ADI AP 100² | <<locked>> | 60% | 18,913 psi | 51% | 1273 fps | 95.3% |
| ADI APS 450² | <<locked>> | 60% | 29,530 psi | 80% | 1237 fps | 100% |
| ADI AS 30² | <<locked>> | 60% | 29,457 psi | 80% | 1273 fps | 100% |
| Alliant BE-86² | <<locked>> | 60% | 28,210 psi | 76% | 1332 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 64% | 20,247 psi | 55% | 1339 fps | 86.3% |
| Alliant Green Dot² | <<locked>> | 60% | 30,066 psi | 81% | 1329 fps | 100% |
| Alliant Herco² | <<locked>> | 60% | 20,450 psi | 55% | 1260 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 60% | 28,094 psi | 76% | 1519 fps | 98.9% |
| Alliant RED DOT² | <<locked>> | 60% | 29,095 psi | 79% | 1286 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 28,079 psi | 76% | 1414 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 29,747 psi | 80% | 1316 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 19,740 psi | 53% | 1155 fps | 100% |
| Hodgdon Clays² | <<locked>> | 60% | 25,222 psi | 68% | 1168 fps | 100% |
| Hodgdon TrailBoss² | 5.1 gr | 60% | 9,993 psi | 27% | 856 fps | 100% |
| Lovex D037.2*² | <<locked>> | 64% | 27,499 psi | 74% | 1522 fps | 87.6% |
| Maxam CSB 1² | <<locked>> | 60% | 25,730 psi | 70% | 1296 fps | 100% |
| Maxam CSB 2² | <<locked>> | 60% | 28,442 psi | 77% | 1335 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 28,950 psi | 78% | 1325 fps | 100% |
| ReloadSwiss RS 14² | 5.2 gr | 60% | 9,485 psi | 26% | 866 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 27,021 psi | 73% | 1388 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 60% | 25,469 psi | 69% | 1467 fps | 93.9% |
| Rottweil P 806² | <<locked>> | 60% | 23,105 psi | 62% | 1421 fps | 99.8% |
| Shooters World Heavy Pistol*² | <<locked>> | 64% | 27,499 psi | 74% | 1522 fps | 87.6% |
| SNPE Vectan A0² | <<locked>> | 60% | 25,585 psi | 69% | 1335 fps | 100% |
| SNPE Vectan BA6 1/2* | <<locked>> | 96% | 24,381 psi | 66% | 1473 fps | 85.8% |
| SNPE Vectan BA7 1/2² | <<locked>> | 60% | 22,452 psi | 61% | 1329 fps | 99.8% |
| Somchem MS200² | <<locked>> | 60% | 28,572 psi | 77% | 1394 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 60% | 26,905 psi | 73% | 1434 fps | 100% |
| Vihtavuori 3N38*² | <<locked>> | 60% | 18,594 psi | 50% | 1289 fps | 89.6% |
| Vihtavuori N105*² | <<locked>> | 60% | 15,708 psi | 42% | 1250 fps | 90.6% |
| Vihtavuori N32C Tin Star² | 6.9 gr | 60% | 16,810 psi | 45% | 1020 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 28,311 psi | 77% | 1391 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 23,366 psi | 63% | 1362 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 60% | 26,948 psi | 73% | 1339 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 3 powders for .357 Auto Mag. loaded with the .357 | 140gr | Speer JHP. Vihtavuori N32C Tin Star delivers the highest muzzle velocity at 1,296 fps; across all powders the maximum-charge window runs from 1,138 fps to 1,296 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 3 of the 3 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (255 MPa), the top charges use 55–90 %, 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 | 140gr | Speer JHP they combine a high case fill with complete burn and sit in the upper velocity band. 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.