Load Specifications
Load data in caliber .357 Auto Mag. with .356 | 125gr | SNS Coated Bullets RN bullet and 36 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% | 1437 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 64% | 30,327 psi | 82% | 1457 fps | 100% |
| Accurate TCM*² | <<locked>> | 68% | 30,342 psi | 82% | 1647 fps | 88.5% |
| ADI AP 100 | <<locked>> | 80% | 32,111 psi | 87% | 1637 fps | 99.4% |
| ADI APS 450² | <<locked>> | 64% | 32,532 psi | 88% | 1355 fps | 100% |
| ADI AS 30² | <<locked>> | 64% | 32,837 psi | 89% | 1398 fps | 100% |
| Alliant BE-86² | <<locked>> | 64% | 31,546 psi | 85% | 1457 fps | 100% |
| Alliant BLUE DOT* | <<locked>> | 80% | 31,676 psi | 86% | 1673 fps | 92.3% |
| Alliant Green Dot² | <<locked>> | 64% | 32,750 psi | 89% | 1447 fps | 100% |
| Alliant Herco² | <<locked>> | 76% | 30,821 psi | 83% | 1535 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 64% | 30,922 psi | 84% | 1657 fps | 98.7% |
| Alliant RED DOT² | <<locked>> | 64% | 31,923 psi | 86% | 1404 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 64% | 30,995 psi | 84% | 1542 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 32,851 psi | 89% | 1437 fps | 100% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 80% | 32,561 psi | 88% | 1440 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 21,915 psi | 59% | 1204 fps | 100% |
| Maxam CSB 1² | <<locked>> | 68% | 31,531 psi | 85% | 1470 fps | 100% |
| Maxam CSB 2² | <<locked>> | 64% | 31,734 psi | 86% | 1460 fps | 100% |
| Maxam CSB 3² | <<locked>> | 64% | 31,343 psi | 85% | 1440 fps | 100% |
| Maxam CSB 4² | <<locked>> | 64% | 32,967 psi | 89% | 1444 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 21,002 psi | 57% | 1224 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 68% | 33,344 psi | 90% | 1572 fps | 100% |
| ReloadSwiss RS 24² | <<locked>> | 68% | 32,663 psi | 88% | 1690 fps | 95.8% |
| Rottweil P 806² | <<locked>> | 68% | 30,530 psi | 83% | 1644 fps | 100% |
| SNPE Vectan A0² | <<locked>> | 68% | 31,401 psi | 85% | 1509 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 64% | 33,199 psi | 90% | 1506 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 72% | 31,314 psi | 85% | 1575 fps | 100% |
| SNPE Vectan BA9 1/2² | <<locked>> | 64% | 33,373 psi | 90% | 1512 fps | 100% |
| Somchem MS200² | <<locked>> | 64% | 31,836 psi | 86% | 1526 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 64% | 29,776 psi | 81% | 1565 fps | 100% |
| Vihtavuori 3N38 | <<locked>> | 80% | 33,315 psi | 90% | 1693 fps | 96.7% |
| Vihtavuori N105 | <<locked>> | 84% | 33,446 psi | 90% | 1742 fps | 99.2% |
| Vihtavuori N32C Tin Star | <<locked>> | 88% | 31,517 psi | 85% | 1339 fps | 100% |
| Vihtavuori N340² | <<locked>> | 64% | 31,662 psi | 86% | 1526 fps | 100% |
| Vihtavuori N350² | <<locked>> | 72% | 32,735 psi | 89% | 1611 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 68% | 33,388 psi | 90% | 1516 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% | 29,646 psi | 80% | 1385 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 60% | 27,195 psi | 74% | 1404 fps | 100% |
| Accurate TCM*² | <<locked>> | 64% | 26,310 psi | 71% | 1558 fps | 85.8% |
| ADI AP 100*² | <<locked>> | 60% | 19,072 psi | 52% | 1335 fps | 93.8% |
| ADI APS 450² | <<locked>> | 60% | 29,196 psi | 79% | 1302 fps | 100% |
| ADI AS 30² | <<locked>> | 60% | 29,356 psi | 79% | 1342 fps | 100% |
| Alliant BE-86² | <<locked>> | 60% | 28,166 psi | 76% | 1404 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 68% | 22,669 psi | 61% | 1463 fps | 86.2% |
| Alliant Green Dot² | <<locked>> | 60% | 29,965 psi | 81% | 1404 fps | 100% |
| Alliant Herco² | <<locked>> | 60% | 20,813 psi | 56% | 1332 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 60% | 27,354 psi | 74% | 1578 fps | 97.6% |
| Alliant RED DOT² | <<locked>> | 60% | 29,037 psi | 79% | 1355 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 28,036 psi | 76% | 1490 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 29,515 psi | 80% | 1385 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 20,117 psi | 54% | 1224 fps | 100% |
| Hodgdon TrailBoss² | 5.1 gr | 60% | 11,052 psi | 30% | 922 fps | 100% |
| Maxam CSB 1² | <<locked>> | 60% | 25,570 psi | 69% | 1368 fps | 100% |
| Maxam CSB 2² | <<locked>> | 60% | 28,587 psi | 77% | 1411 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 28,137 psi | 76% | 1388 fps | 100% |
| Maxam CSB 4² | <<locked>> | 60% | 30,081 psi | 81% | 1398 fps | 100% |
| ReloadSwiss RS 14² | 5.2 gr | 60% | 10,660 psi | 29% | 935 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 26,760 psi | 72% | 1460 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 60% | 25,367 psi | 69% | 1532 fps | 91.9% |
| Rottweil P 806² | <<locked>> | 60% | 23,511 psi | 64% | 1499 fps | 99.4% |
| SNPE Vectan A0² | <<locked>> | 60% | 25,295 psi | 68% | 1401 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 60% | 29,675 psi | 80% | 1450 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 60% | 22,437 psi | 61% | 1394 fps | 99.3% |
| SNPE Vectan BA9 1/2² | <<locked>> | 60% | 29,704 psi | 80% | 1450 fps | 100% |
| Somchem MS200² | <<locked>> | 60% | 28,297 psi | 77% | 1467 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 60% | 26,295 psi | 71% | 1499 fps | 100% |
| Vihtavuori 3N38*² | <<locked>> | 60% | 18,637 psi | 50% | 1345 fps | 87.5% |
| Vihtavuori N105*² | <<locked>> | 60% | 15,896 psi | 43% | 1312 fps | 88.6% |
| Vihtavuori N32C Tin Star² | 6.9 gr | 60% | 17,767 psi | 48% | 1089 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 28,079 psi | 76% | 1467 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 23,279 psi | 63% | 1427 fps | 99.9% |
| Winchester AutoComp ² | <<locked>> | 60% | 26,992 psi | 73% | 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 4 powders for .357 Auto Mag. loaded with the .356 | 125gr | SNS Coated Bullets RN. Vihtavuori N105 delivers the highest muzzle velocity at 1,742 fps; across all powders the maximum-charge window runs from 1,204 fps to 1,742 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 4 of the 4 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 | 125gr | SNS Coated Bullets RN 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.