Load Specifications
Load data in caliber .357 Auto Mag. with .355 | 124gr | X-TREME FP bullet and 37 powders. The key underlying parameters are shown in the table above.
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% | 33,286 psi | 90% | 1457 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 64% | 30,545 psi | 83% | 1473 fps | 100% |
| Accurate TCM*² | <<locked>> | 68% | 30,937 psi | 84% | 1673 fps | 89% |
| ADI AP 100 | <<locked>> | 80% | 32,721 psi | 88% | 1660 fps | 99.5% |
| ADI APS 350² | <<locked>> | 64% | 33,344 psi | 90% | 1348 fps | 100% |
| ADI APS 450² | <<locked>> | 64% | 32,793 psi | 89% | 1375 fps | 100% |
| ADI AS 30² | <<locked>> | 64% | 33,199 psi | 90% | 1417 fps | 100% |
| Alliant BE-86² | <<locked>> | 64% | 31,952 psi | 86% | 1476 fps | 100% |
| Alliant BLUE DOT* | <<locked>> | 80% | 32,430 psi | 88% | 1706 fps | 92.8% |
| Alliant Green Dot² | <<locked>> | 64% | 33,011 psi | 89% | 1467 fps | 100% |
| Alliant Herco² | <<locked>> | 76% | 31,198 psi | 84% | 1555 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 64% | 31,720 psi | 86% | 1683 fps | 98.9% |
| Alliant RED DOT² | <<locked>> | 64% | 32,329 psi | 87% | 1424 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 64% | 31,633 psi | 86% | 1568 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 33,025 psi | 89% | 1453 fps | 100% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 80% | 33,402 psi | 90% | 1467 fps | 100% |
| Hodgdon Clays² | <<locked>> | 72% | 32,663 psi | 88% | 1368 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 22,205 psi | 60% | 1220 fps | 100% |
| Lovex D037.2*² | <<locked>> | 68% | 31,647 psi | 86% | 1690 fps | 88% |
| Maxam CSB 1² | <<locked>> | 68% | 31,705 psi | 86% | 1486 fps | 100% |
| Maxam CSB 2² | <<locked>> | 64% | 32,503 psi | 88% | 1486 fps | 100% |
| Maxam CSB 3² | <<locked>> | 64% | 32,155 psi | 87% | 1467 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 21,292 psi | 58% | 1240 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 64% | 30,284 psi | 82% | 1535 fps | 100% |
| ReloadSwiss RS 24² | <<locked>> | 68% | 33,083 psi | 89% | 1713 fps | 96% |
| Rottweil P 806² | <<locked>> | 68% | 31,285 psi | 85% | 1667 fps | 100% |
| Shooters World Heavy Pistol*² | <<locked>> | 68% | 31,647 psi | 86% | 1690 fps | 88% |
| SNPE Vectan A0² | <<locked>> | 68% | 31,952 psi | 86% | 1532 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 72% | 31,966 psi | 86% | 1601 fps | 100% |
| Somchem MS200² | <<locked>> | 64% | 31,923 psi | 86% | 1542 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 64% | 30,603 psi | 83% | 1591 fps | 100% |
| Vihtavuori 3N38² | <<locked>> | 76% | 30,298 psi | 82% | 1644 fps | 95.6% |
| Vihtavuori N105 | <<locked>> | 80% | 30,676 psi | 83% | 1699 fps | 98.6% |
| Vihtavuori N32C Tin Star | <<locked>> | 88% | 31,589 psi | 85% | 1352 fps | 100% |
| Vihtavuori N340² | <<locked>> | 64% | 32,198 psi | 87% | 1549 fps | 100% |
| Vihtavuori N350² | <<locked>> | 68% | 29,718 psi | 80% | 1575 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 64% | 30,501 psi | 82% | 1486 fps | 100% |
Start Load - Barrel Length: 6.5"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate Solo 1000² | <<locked>> | 60% | 29,994 psi | 81% | 1404 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 60% | 27,470 psi | 74% | 1421 fps | 100% |
| Accurate TCM*² | <<locked>> | 64% | 26,963 psi | 73% | 1585 fps | 86.4% |
| ADI AP 100*² | <<locked>> | 60% | 19,189 psi | 52% | 1348 fps | 94% |
| ADI APS 350² | <<locked>> | 60% | 30,400 psi | 82% | 1302 fps | 100% |
| ADI APS 450² | <<locked>> | 60% | 29,559 psi | 80% | 1322 fps | 100% |
| ADI AS 30² | <<locked>> | 60% | 29,776 psi | 81% | 1362 fps | 100% |
| Alliant BE-86² | <<locked>> | 60% | 28,282 psi | 76% | 1417 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 68% | 23,177 psi | 63% | 1490 fps | 86.8% |
| Alliant Green Dot² | <<locked>> | 60% | 30,313 psi | 82% | 1424 fps | 100% |
| Alliant Herco² | <<locked>> | 60% | 20,972 psi | 57% | 1345 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 60% | 27,746 psi | 75% | 1601 fps | 97.8% |
| Alliant RED DOT² | <<locked>> | 60% | 28,964 psi | 78% | 1368 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 28,282 psi | 76% | 1506 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 29,791 psi | 81% | 1404 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 20,349 psi | 55% | 1237 fps | 100% |
| Hodgdon Clays² | <<locked>> | 60% | 24,976 psi | 68% | 1240 fps | 100% |
| Hodgdon TrailBoss² | <<locked>> | 60% | 10,979 psi | 30% | 928 fps | 100% |
| Lovex D037.2*² | <<locked>> | 64% | 27,572 psi | 75% | 1601 fps | 85.4% |
| Maxam CSB 1² | <<locked>> | 60% | 25,875 psi | 70% | 1385 fps | 100% |
| Maxam CSB 2² | <<locked>> | 60% | 29,385 psi | 79% | 1437 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 29,008 psi | 78% | 1414 fps | 100% |
| ReloadSwiss RS 14² | <<locked>> | 60% | 10,588 psi | 29% | 938 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 26,934 psi | 73% | 1476 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 60% | 25,541 psi | 69% | 1549 fps | 92.2% |
| Rottweil P 806² | <<locked>> | 60% | 24,004 psi | 65% | 1522 fps | 99.5% |
| Shooters World Heavy Pistol*² | <<locked>> | 64% | 27,572 psi | 75% | 1601 fps | 85.4% |
| SNPE Vectan A0² | <<locked>> | 60% | 25,933 psi | 70% | 1427 fps | 100% |
| SNPE Vectan BA7 1/2² | <<locked>> | 60% | 22,858 psi | 62% | 1417 fps | 99.4% |
| Somchem MS200² | <<locked>> | 60% | 28,993 psi | 78% | 1490 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 60% | 27,122 psi | 73% | 1526 fps | 100% |
| Vihtavuori 3N38*² | <<locked>> | 60% | 18,985 psi | 51% | 1365 fps | 88% |
| Vihtavuori N105*² | <<locked>> | 60% | 16,520 psi | 45% | 1342 fps | 89.5% |
| Vihtavuori N32C Tin Star² | <<locked>> | 60% | 17,854 psi | 48% | 1102 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 28,718 psi | 78% | 1490 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 23,815 psi | 64% | 1450 fps | 99.9% |
| Winchester AutoComp ² | <<locked>> | 60% | 27,064 psi | 73% | 1427 fps | 100% |
* 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 37 powders for .357 Auto Mag. loaded with the .355 | 124gr | X-TREME FP. ReloadSwiss RS 24 delivers the highest muzzle velocity at 1,713 fps; across all powders the maximum-charge window runs from 1,220 fps to 1,713 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 7 of the 37 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (255 MPa), the top charges use 58–90 %, 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. As outliers, Accurate TCM, Alliant BLUE DOT, Lovex D037.2 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.