Load Specifications
Load data in caliber .357 Auto Mag. with .356 | 123gr | LOS 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% | 33,054 psi | 89% | 1453 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 64% | 30,298 psi | 82% | 1470 fps | 100% |
| Accurate TCM*² | <<locked>> | 68% | 30,023 psi | 81% | 1654 fps | 88.1% |
| ADI AP 100 | <<locked>> | 80% | 31,908 psi | 86% | 1647 fps | 99.3% |
| ADI APS 350² | <<locked>> | 64% | 33,069 psi | 89% | 1342 fps | 100% |
| ADI APS 450² | <<locked>> | 64% | 32,039 psi | 87% | 1362 fps | 100% |
| ADI AS 30² | <<locked>> | 64% | 32,285 psi | 87% | 1404 fps | 100% |
| Alliant BE-86² | <<locked>> | 64% | 31,444 psi | 85% | 1470 fps | 100% |
| Alliant BLUE DOT* | <<locked>> | 80% | 31,314 psi | 85% | 1683 fps | 91.9% |
| Alliant Green Dot² | <<locked>> | 64% | 32,750 psi | 89% | 1463 fps | 100% |
| Alliant Herco² | <<locked>> | 76% | 30,647 psi | 83% | 1549 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 64% | 30,690 psi | 83% | 1667 fps | 98.5% |
| Alliant RED DOT² | <<locked>> | 64% | 31,415 psi | 85% | 1411 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 64% | 30,937 psi | 84% | 1558 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 32,808 psi | 89% | 1450 fps | 100% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 80% | 32,938 psi | 89% | 1460 fps | 100% |
| Hodgdon Clays² | <<locked>> | 72% | 32,474 psi | 88% | 1365 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 21,944 psi | 59% | 1217 fps | 100% |
| Maxam CSB 1² | <<locked>> | 68% | 31,488 psi | 85% | 1483 fps | 100% |
| Maxam CSB 2² | <<locked>> | 64% | 31,734 psi | 86% | 1476 fps | 100% |
| Maxam CSB 3² | <<locked>> | 64% | 31,343 psi | 85% | 1457 fps | 100% |
| Maxam CSB 4² | <<locked>> | 64% | 32,953 psi | 89% | 1457 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 21,016 psi | 57% | 1237 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 68% | 33,185 psi | 90% | 1585 fps | 100% |
| ReloadSwiss RS 24² | <<locked>> | 68% | 32,300 psi | 87% | 1699 fps | 95.5% |
| Rottweil P 806² | <<locked>> | 68% | 30,530 psi | 83% | 1660 fps | 100% |
| SNPE Vectan A0² | <<locked>> | 68% | 31,299 psi | 85% | 1526 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 64% | 33,083 psi | 89% | 1519 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 72% | 31,067 psi | 84% | 1588 fps | 100% |
| SNPE Vectan BA9 1/2² | <<locked>> | 64% | 33,315 psi | 90% | 1526 fps | 100% |
| Somchem MS200² | <<locked>> | 64% | 31,763 psi | 86% | 1542 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 68% | 33,359 psi | 90% | 1644 fps | 100% |
| Vihtavuori 3N38 | <<locked>> | 80% | 32,996 psi | 89% | 1699 fps | 96.4% |
| Vihtavuori N105 | <<locked>> | 80% | 29,718 psi | 80% | 1686 fps | 98.2% |
| Vihtavuori N32C Tin Star | <<locked>> | 88% | 30,980 psi | 84% | 1345 fps | 100% |
| Vihtavuori N340² | <<locked>> | 64% | 31,560 psi | 85% | 1542 fps | 100% |
| Vihtavuori N350² | <<locked>> | 72% | 32,518 psi | 88% | 1624 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 68% | 33,214 psi | 90% | 1532 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% | 29,689 psi | 80% | 1401 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 60% | 27,180 psi | 73% | 1417 fps | 100% |
| Accurate TCM*² | <<locked>> | 64% | 26,368 psi | 71% | 1572 fps | 85.6% |
| ADI AP 100*² | <<locked>> | 60% | 19,000 psi | 51% | 1345 fps | 93.5% |
| ADI APS 350² | <<locked>> | 60% | 30,052 psi | 81% | 1296 fps | 100% |
| ADI APS 450² | <<locked>> | 60% | 29,254 psi | 79% | 1319 fps | 100% |
| ADI AS 30² | <<locked>> | 60% | 29,457 psi | 80% | 1358 fps | 100% |
| Alliant BE-86² | <<locked>> | 60% | 28,123 psi | 76% | 1417 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 68% | 22,785 psi | 62% | 1480 fps | 86.1% |
| Alliant Green Dot² | <<locked>> | 60% | 29,443 psi | 80% | 1407 fps | 100% |
| Alliant Herco² | <<locked>> | 60% | 20,784 psi | 56% | 1345 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 60% | 27,224 psi | 74% | 1591 fps | 97.4% |
| Alliant RED DOT² | <<locked>> | 60% | 28,572 psi | 77% | 1362 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 28,007 psi | 76% | 1506 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 29,530 psi | 80% | 1401 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 20,102 psi | 54% | 1237 fps | 100% |
| Hodgdon Clays² | <<locked>> | 60% | 24,656 psi | 67% | 1234 fps | 100% |
| Hodgdon TrailBoss² | 5.1 gr | 60% | 10,892 psi | 29% | 928 fps | 100% |
| Maxam CSB 1² | <<locked>> | 60% | 25,599 psi | 69% | 1381 fps | 100% |
| Maxam CSB 2² | <<locked>> | 60% | 28,558 psi | 77% | 1424 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 28,181 psi | 76% | 1404 fps | 100% |
| Maxam CSB 4² | <<locked>> | 60% | 30,153 psi | 82% | 1414 fps | 100% |
| ReloadSwiss RS 14² | 5.2 gr | 60% | 10,530 psi | 28% | 938 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 26,716 psi | 72% | 1473 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 60% | 25,150 psi | 68% | 1542 fps | 91.6% |
| Rottweil P 806² | <<locked>> | 60% | 23,250 psi | 63% | 1506 fps | 99.2% |
| SNPE Vectan A0² | <<locked>> | 60% | 25,266 psi | 68% | 1414 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 60% | 29,617 psi | 80% | 1467 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 60% | 22,408 psi | 61% | 1404 fps | 99.2% |
| SNPE Vectan BA9 1/2² | <<locked>> | 60% | 29,689 psi | 80% | 1467 fps | 100% |
| Somchem MS200² | <<locked>> | 60% | 28,297 psi | 77% | 1483 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 60% | 26,614 psi | 72% | 1519 fps | 100% |
| Vihtavuori 3N38*² | <<locked>> | 60% | 18,536 psi | 50% | 1352 fps | 87.1% |
| Vihtavuori N105*² | <<locked>> | 60% | 16,041 psi | 43% | 1329 fps | 88.5% |
| Vihtavuori N32C Tin Star² | 6.9 gr | 60% | 17,506 psi | 47% | 1096 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 28,036 psi | 76% | 1480 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 23,192 psi | 63% | 1440 fps | 99.8% |
| Winchester AutoComp ² | <<locked>> | 60% | 26,934 psi | 73% | 1427 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 .356 | 123gr | LOS RN. ReloadSwiss RS 24 delivers the highest muzzle velocity at 1,699 fps; across all powders the maximum-charge window runs from 1,217 fps to 1,699 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 57–90 %, 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 .356 | 123gr | LOS 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.