Load Specifications
Load data in caliber .357 Auto Mag. with .357 | 127gr | H&N KS HS bullet and 49 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, Hodgdon TrailBoss 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 ≥ 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. 2² | <<locked>> | 64% | 32,416 psi | 88% | 1552 fps | 100% |
| Accurate No. 7*² | <<locked>> | 64% | 31,430 psi | 85% | 1690 fps | 93.6% |
| Accurate No. 9*² | <<locked>> | 72% | 31,459 psi | 85% | 1683 fps | 88.2% |
| Accurate Solo 1000² | <<locked>> | 64% | 31,343 psi | 85% | 1421 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 68% | 31,328 psi | 85% | 1480 fps | 100% |
| Accurate TCM*² | <<locked>> | 72% | 31,705 psi | 86% | 1683 fps | 89.7% |
| ADI AP 100 | <<locked>> | 80% | 29,849 psi | 81% | 1604 fps | 99.1% |
| ADI APS 350² | <<locked>> | 64% | 32,358 psi | 87% | 1322 fps | 100% |
| ADI APS 450² | <<locked>> | 64% | 31,270 psi | 85% | 1342 fps | 100% |
| ADI AS 30² | <<locked>> | 64% | 30,589 psi | 83% | 1375 fps | 100% |
| Alliant BE-86² | <<locked>> | 68% | 32,837 psi | 89% | 1490 fps | 100% |
| Alliant BLUE DOT* | <<locked>> | 84% | 32,387 psi | 88% | 1699 fps | 93% |
| Alliant Green Dot² | <<locked>> | 64% | 32,053 psi | 87% | 1440 fps | 100% |
| Alliant Herco | <<locked>> | 80% | 31,314 psi | 85% | 1558 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 68% | 32,343 psi | 87% | 1693 fps | 99.2% |
| Alliant RED DOT² | <<locked>> | 68% | 32,576 psi | 88% | 1427 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 68% | 32,140 psi | 87% | 1578 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 30,545 psi | 83% | 1414 fps | 100% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 84% | 33,301 psi | 90% | 1460 fps | 100% |
| Hodgdon Clays² | <<locked>> | 72% | 31,604 psi | 85% | 1342 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 19,580 psi | 53% | 1181 fps | 100% |
| Hodgdon Universal² | <<locked>> | 64% | 33,170 psi | 90% | 1522 fps | 100% |
| Lovex D037.1*² | <<locked>> | 64% | 31,430 psi | 85% | 1690 fps | 93.6% |
| Lovex D037.2*² | <<locked>> | 72% | 32,343 psi | 87% | 1699 fps | 88.7% |
| Maxam CSB 1² | <<locked>> | 72% | 32,938 psi | 89% | 1499 fps | 100% |
| Maxam CSB 2² | <<locked>> | 68% | 32,227 psi | 87% | 1486 fps | 100% |
| Maxam CSB 3² | <<locked>> | 68% | 33,112 psi | 90% | 1476 fps | 100% |
| Maxam CSB 4² | <<locked>> | 64% | 31,488 psi | 85% | 1430 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 17,695 psi | 48% | 1181 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 68% | 31,096 psi | 84% | 1549 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 68% | 29,878 psi | 81% | 1647 fps | 94.9% |
| Rottweil P 806² | <<locked>> | 72% | 30,037 psi | 81% | 1650 fps | 100% |
| Shooters World Heavy Pistol*² | <<locked>> | 72% | 32,343 psi | 87% | 1699 fps | 88.7% |
| Shooters World Major Pistol*² | <<locked>> | 64% | 31,430 psi | 85% | 1690 fps | 93.6% |
| SNPE Vectan A0² | <<locked>> | 72% | 32,851 psi | 89% | 1542 fps | 100% |
| SNPE Vectan A1² | <<locked>> | 64% | 32,401 psi | 88% | 1476 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 64% | 31,676 psi | 86% | 1490 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 76% | 32,750 psi | 89% | 1608 fps | 100% |
| SNPE Vectan BA9 1/2² | <<locked>> | 64% | 30,879 psi | 83% | 1483 fps | 100% |
| SNPE Vectan SP 2² | <<locked>> | 64% | 32,837 psi | 89% | 1703 fps | 99.9% |
| Somchem MP200² | <<locked>> | 64% | 33,156 psi | 90% | 1585 fps | 100% |
| Somchem MS200² | <<locked>> | 68% | 33,011 psi | 89% | 1555 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 68% | 31,038 psi | 84% | 1598 fps | 100% |
| Vihtavuori 3N38 | <<locked>> | 80% | 30,676 psi | 83% | 1650 fps | 96% |
| Vihtavuori N105 | <<locked>> | 84% | 30,342 psi | 82% | 1693 fps | 98.6% |
| Vihtavuori N32C Tin Star | <<locked>> | 92% | 31,096 psi | 84% | 1348 fps | 100% |
| Vihtavuori N340² | <<locked>> | 68% | 33,330 psi | 90% | 1562 fps | 100% |
| Vihtavuori N350² | <<locked>> | 72% | 30,313 psi | 82% | 1578 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 68% | 30,966 psi | 84% | 1493 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. 2² | <<locked>> | 60% | 28,224 psi | 76% | 1483 fps | 100% |
| Accurate No. 7*² | <<locked>> | 60% | 26,760 psi | 72% | 1591 fps | 90.9% |
| Accurate No. 9*² | <<locked>> | 68% | 27,383 psi | 74% | 1598 fps | 85.5% |
| Accurate Solo 1000² | <<locked>> | 60% | 28,500 psi | 77% | 1375 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 60% | 24,860 psi | 67% | 1375 fps | 100% |
| Accurate TCM*² | <<locked>> | 68% | 27,557 psi | 75% | 1598 fps | 87.1% |
| ADI AP 100*² | <<locked>> | 60% | 16,534 psi | 45% | 1276 fps | 91.6% |
| ADI APS 350² | <<locked>> | 60% | 29,327 psi | 79% | 1276 fps | 100% |
| ADI APS 450² | <<locked>> | 60% | 28,500 psi | 77% | 1296 fps | 100% |
| ADI AS 30² | <<locked>> | 60% | 27,717 psi | 75% | 1329 fps | 100% |
| Alliant BE-86² | <<locked>> | 60% | 25,947 psi | 70% | 1378 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 72% | 22,611 psi | 61% | 1480 fps | 86.5% |
| Alliant Green Dot² | <<locked>> | 60% | 28,747 psi | 78% | 1388 fps | 100% |
| Alliant Herco² | <<locked>> | 60% | 18,144 psi | 49% | 1286 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 60% | 24,976 psi | 68% | 1535 fps | 96.7% |
| Alliant RED DOT² | <<locked>> | 60% | 26,687 psi | 72% | 1332 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 25,019 psi | 68% | 1450 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 27,238 psi | 74% | 1362 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 17,738 psi | 48% | 1194 fps | 100% |
| Hodgdon Clays² | <<locked>> | 60% | 23,670 psi | 64% | 1214 fps | 100% |
| Hodgdon TrailBoss² | 5.1 gr | 60% | 8,180 psi | 22% | 866 fps | 100% |
| Hodgdon Universal² | <<locked>> | 60% | 29,283 psi | 79% | 1463 fps | 100% |
| Lovex D037.1*² | <<locked>> | 60% | 26,760 psi | 72% | 1591 fps | 90.9% |
| Lovex D037.2*² | <<locked>> | 68% | 27,746 psi | 75% | 1604 fps | 85.8% |
| Maxam CSB 1² | <<locked>> | 60% | 23,206 psi | 63% | 1335 fps | 100% |
| Maxam CSB 2² | <<locked>> | 60% | 25,715 psi | 70% | 1381 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 26,513 psi | 72% | 1371 fps | 100% |
| Maxam CSB 4² | <<locked>> | 60% | 28,079 psi | 76% | 1375 fps | 100% |
| ReloadSwiss RS 14² | 5.2 gr | 60% | 7,498 psi | 20% | 860 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 24,033 psi | 65% | 1424 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 60% | 22,669 psi | 61% | 1480 fps | 90.3% |
| Rottweil P 806² | <<locked>> | 60% | 19,145 psi | 52% | 1407 fps | 97.6% |
| Shooters World Heavy Pistol*² | <<locked>> | 68% | 27,746 psi | 75% | 1604 fps | 85.8% |
| Shooters World Major Pistol*² | <<locked>> | 60% | 26,760 psi | 72% | 1591 fps | 90.9% |
| SNPE Vectan A0² | <<locked>> | 60% | 23,612 psi | 64% | 1381 fps | 100% |
| SNPE Vectan A1² | <<locked>> | 60% | 28,877 psi | 78% | 1424 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 60% | 28,152 psi | 76% | 1434 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 60% | 20,247 psi | 55% | 1355 fps | 98.6% |
| SNPE Vectan BA9 1/2² | <<locked>> | 60% | 27,731 psi | 75% | 1430 fps | 100% |
| SNPE Vectan SP 2² | <<locked>> | 60% | 28,369 psi | 77% | 1617 fps | 99.1% |
| Somchem MP200² | <<locked>> | 60% | 29,008 psi | 78% | 1516 fps | 100% |
| Somchem MS200² | <<locked>> | 60% | 26,310 psi | 71% | 1444 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 60% | 23,757 psi | 64% | 1457 fps | 99.9% |
| Vihtavuori 3N38*² | <<locked>> | 64% | 18,101 psi | 49% | 1348 fps | 87.1% |
| Vihtavuori N105*² | <<locked>> | 64% | 14,852 psi | 40% | 1296 fps | 87.2% |
| Vihtavuori N32C Tin Star² | 7 gr | 60% | 14,910 psi | 40% | 1056 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 25,904 psi | 70% | 1440 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 20,914 psi | 57% | 1388 fps | 99.5% |
| Winchester AutoComp ² | <<locked>> | 60% | 24,569 psi | 66% | 1381 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 49 powders for .357 Auto Mag. loaded with the .357 | 127gr | H&N KS HS. SNPE Vectan SP 2 delivers the highest muzzle velocity at 1,703 fps; across all powders the maximum-charge window runs from 1,181 fps to 1,703 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 9 of the 49 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (255 MPa), the top charges use 48–90 %, 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, Hodgdon TrailBoss, ReloadSwiss RS 14 rank at the top here: for .357 Auto Mag. with the .357 | 127gr | H&N KS HS they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate No. 7, Accurate No. 9, Accurate TCM 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.