Load Specifications
Load data in caliber .357 Auto Mag. with .356 | 121gr | Hornady HAP bullet and 44 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. 2² | <<locked>> | 64% | 33,054 psi | 89% | 1601 fps | 100% |
| Accurate No. 7*² | <<locked>> | 64% | 32,721 psi | 88% | 1752 fps | 93.6% |
| Accurate No. 9*² | <<locked>> | 72% | 32,895 psi | 89% | 1745 fps | 88.3% |
| Accurate Solo 1000² | <<locked>> | 64% | 32,155 psi | 87% | 1470 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 68% | 32,155 psi | 87% | 1532 fps | 100% |
| Accurate TCM*² | <<locked>> | 72% | 33,185 psi | 90% | 1749 fps | 89.8% |
| ADI AP 100 | <<locked>> | 80% | 31,154 psi | 84% | 1667 fps | 99.1% |
| ADI APS 350² | <<locked>> | 64% | 32,634 psi | 88% | 1365 fps | 100% |
| ADI APS 450² | <<locked>> | 64% | 31,459 psi | 85% | 1381 fps | 100% |
| ADI AS 30² | <<locked>> | 64% | 31,241 psi | 84% | 1421 fps | 100% |
| Alliant BE-86² | <<locked>> | 64% | 30,139 psi | 81% | 1483 fps | 100% |
| Alliant BLUE DOT* | <<locked>> | 80% | 29,863 psi | 81% | 1680 fps | 91% |
| Alliant Green Dot² | <<locked>> | 64% | 31,488 psi | 85% | 1476 fps | 100% |
| Alliant Herco | <<locked>> | 80% | 32,242 psi | 87% | 1608 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 68% | 33,330 psi | 90% | 1752 fps | 99.1% |
| Alliant RED DOT² | <<locked>> | 64% | 30,342 psi | 82% | 1427 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 68% | 33,185 psi | 90% | 1631 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 31,488 psi | 85% | 1463 fps | 100% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 80% | 31,502 psi | 85% | 1473 fps | 100% |
| Hodgdon Clays² | <<locked>> | 72% | 31,792 psi | 86% | 1381 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 20,523 psi | 55% | 1224 fps | 100% |
| Lovex D037.1*² | <<locked>> | 64% | 32,721 psi | 88% | 1752 fps | 93.6% |
| Maxam CSB 1² | <<locked>> | 68% | 30,052 psi | 81% | 1493 fps | 100% |
| Maxam CSB 2² | <<locked>> | 64% | 30,284 psi | 82% | 1490 fps | 100% |
| Maxam CSB 3² | <<locked>> | 64% | 30,676 psi | 83% | 1476 fps | 100% |
| Maxam CSB 4² | <<locked>> | 64% | 32,401 psi | 88% | 1483 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 19,305 psi | 52% | 1237 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 68% | 31,894 psi | 86% | 1598 fps | 100% |
| ReloadSwiss RS 24² | <<locked>> | 68% | 31,212 psi | 84% | 1709 fps | 95% |
| Rottweil P 806² | <<locked>> | 72% | 31,981 psi | 86% | 1719 fps | 100% |
| Shooters World Major Pistol*² | <<locked>> | 64% | 32,721 psi | 88% | 1752 fps | 93.6% |
| SNPE Vectan A0² | <<locked>> | 68% | 30,400 psi | 82% | 1539 fps | 100% |
| SNPE Vectan A1² | <<locked>> | 64% | 32,938 psi | 89% | 1526 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 64% | 32,213 psi | 87% | 1535 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 72% | 30,008 psi | 81% | 1598 fps | 100% |
| SNPE Vectan BA9 1/2² | <<locked>> | 64% | 31,763 psi | 86% | 1535 fps | 100% |
| Somchem MS200² | <<locked>> | 64% | 30,240 psi | 82% | 1549 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 68% | 32,155 psi | 87% | 1654 fps | 100% |
| Vihtavuori 3N38 | <<locked>> | 80% | 31,589 psi | 85% | 1703 fps | 95.9% |
| Vihtavuori N105 | <<locked>> | 84% | 31,821 psi | 86% | 1759 fps | 98.7% |
| Vihtavuori N32C Tin Star | <<locked>> | 92% | 32,184 psi | 87% | 1394 fps | 100% |
| Vihtavuori N340² | <<locked>> | 64% | 30,342 psi | 82% | 1555 fps | 100% |
| Vihtavuori N350² | <<locked>> | 72% | 31,401 psi | 85% | 1637 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 68% | 31,749 psi | 86% | 1542 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% | 29,008 psi | 78% | 1535 fps | 100% |
| Accurate No. 7*² | <<locked>> | 60% | 27,847 psi | 75% | 1647 fps | 90.9% |
| Accurate No. 9*² | <<locked>> | 68% | 28,543 psi | 77% | 1654 fps | 85.6% |
| Accurate Solo 1000² | <<locked>> | 60% | 28,863 psi | 78% | 1414 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 60% | 25,933 psi | 70% | 1427 fps | 100% |
| Accurate TCM*² | <<locked>> | 68% | 28,718 psi | 78% | 1654 fps | 87.1% |
| ADI AP 100*² | <<locked>> | 60% | 17,492 psi | 47% | 1332 fps | 92% |
| ADI APS 350² | <<locked>> | 60% | 29,718 psi | 80% | 1319 fps | 100% |
| ADI APS 450² | <<locked>> | 60% | 28,776 psi | 78% | 1339 fps | 100% |
| ADI AS 30² | <<locked>> | 60% | 28,500 psi | 77% | 1375 fps | 100% |
| Alliant BE-86² | <<locked>> | 60% | 26,919 psi | 73% | 1430 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 72% | 23,757 psi | 64% | 1539 fps | 86.7% |
| Alliant Green Dot² | <<locked>> | 60% | 28,819 psi | 78% | 1430 fps | 100% |
| Alliant Herco² | <<locked>> | 60% | 19,131 psi | 52% | 1335 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 60% | 26,165 psi | 71% | 1598 fps | 96.9% |
| Alliant RED DOT² | <<locked>> | 60% | 27,557 psi | 75% | 1378 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 26,310 psi | 71% | 1506 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 28,268 psi | 76% | 1414 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 18,623 psi | 50% | 1237 fps | 100% |
| Hodgdon Clays² | <<locked>> | 60% | 24,178 psi | 65% | 1253 fps | 100% |
| Hodgdon TrailBoss² | 5.3 gr | 60% | 9,514 psi | 26% | 922 fps | 100% |
| Lovex D037.1*² | <<locked>> | 60% | 27,847 psi | 75% | 1647 fps | 90.9% |
| Maxam CSB 1² | <<locked>> | 60% | 24,308 psi | 66% | 1388 fps | 100% |
| Maxam CSB 2² | <<locked>> | 60% | 27,238 psi | 74% | 1440 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 27,050 psi | 73% | 1414 fps | 100% |
| Maxam CSB 4² | <<locked>> | 60% | 29,095 psi | 79% | 1427 fps | 100% |
| ReloadSwiss RS 14² | 5.4 gr | 60% | 8,992 psi | 24% | 925 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 25,034 psi | 68% | 1476 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 60% | 23,801 psi | 64% | 1539 fps | 90.5% |
| Rottweil P 806² | <<locked>> | 60% | 21,016 psi | 57% | 1483 fps | 98.2% |
| Shooters World Major Pistol*² | <<locked>> | 60% | 27,847 psi | 75% | 1647 fps | 90.9% |
| SNPE Vectan A0² | <<locked>> | 60% | 24,453 psi | 66% | 1430 fps | 100% |
| SNPE Vectan A1² | <<locked>> | 60% | 29,559 psi | 80% | 1470 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 60% | 28,805 psi | 78% | 1483 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 60% | 21,118 psi | 57% | 1407 fps | 98.7% |
| SNPE Vectan BA9 1/2² | <<locked>> | 60% | 28,718 psi | 78% | 1483 fps | 100% |
| Somchem MS200² | <<locked>> | 60% | 27,325 psi | 74% | 1496 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 60% | 25,106 psi | 68% | 1519 fps | 99.9% |
| Vihtavuori 3N38*² | <<locked>> | 60% | 17,114 psi | 46% | 1342 fps | 85.2% |
| Vihtavuori N105*² | <<locked>> | 60% | 14,214 psi | 38% | 1293 fps | 85.3% |
| Vihtavuori N32C Tin Star² | 7.2 gr | 60% | 16,157 psi | 44% | 1102 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 26,890 psi | 73% | 1490 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 21,886 psi | 59% | 1440 fps | 99.6% |
| Winchester AutoComp ² | <<locked>> | 60% | 25,628 psi | 69% | 1434 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 44 powders for .357 Auto Mag. loaded with the .356 | 121gr | Hornady HAP. Vihtavuori N105 delivers the highest muzzle velocity at 1,759 fps; across all powders the maximum-charge window runs from 1,224 fps to 1,759 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 9 of the 44 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (255 MPa), the top charges use 52–90 %, 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 | 121gr | Hornady HAP 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.