Load Specifications
Load data in caliber .357 Auto Mag. with .356 | 135gr | X-TREME RNFP bullet and 34 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 No. 9*² | <<locked>> | 68% | 32,764 psi | 89% | 1647 fps | 90.3% |
| Accurate Solo 1250² | <<locked>> | 64% | 31,473 psi | 85% | 1417 fps | 100% |
| Accurate TCM*² | <<locked>> | 68% | 32,837 psi | 89% | 1644 fps | 91.6% |
| ADI AP 100² | <<locked>> | 76% | 30,966 psi | 84% | 1558 fps | 99.7% |
| ADI APS 450² | <<locked>> | 64% | 33,228 psi | 90% | 1316 fps | 100% |
| Alliant BE-86² | <<locked>> | 64% | 32,982 psi | 89% | 1421 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 76% | 30,487 psi | 82% | 1594 fps | 93.2% |
| Alliant Herco² | <<locked>> | 76% | 32,822 psi | 89% | 1506 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 64% | 33,127 psi | 90% | 1640 fps | 99.7% |
| Alliant RED DOT² | <<locked>> | 64% | 32,967 psi | 89% | 1365 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 64% | 32,764 psi | 89% | 1509 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 76% | 31,488 psi | 85% | 1368 fps | 100% |
| Hodgdon Clays² | <<locked>> | 68% | 30,937 psi | 84% | 1280 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 23,163 psi | 63% | 1178 fps | 100% |
| Lovex D037.2*² | <<locked>> | 64% | 29,298 psi | 79% | 1575 fps | 88.2% |
| Maxam CSB 1² | <<locked>> | 68% | 33,199 psi | 90% | 1437 fps | 100% |
| Maxam CSB 3² | <<locked>> | 64% | 32,967 psi | 89% | 1407 fps | 100% |
| Ramshot Enforcer*² | <<locked>> | 76% | 31,531 psi | 85% | 1650 fps | 87.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 21,901 psi | 59% | 1191 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 64% | 31,517 psi | 85% | 1480 fps | 100% |
| ReloadSwiss RS 24² | <<locked>> | 64% | 30,879 psi | 83% | 1601 fps | 96.3% |
| Rottweil P 806² | <<locked>> | 68% | 33,286 psi | 90% | 1627 fps | 100% |
| Shooters World Heavy Pistol*² | <<locked>> | 64% | 29,298 psi | 79% | 1575 fps | 88.2% |
| SNPE Vectan A0² | <<locked>> | 68% | 33,011 psi | 89% | 1476 fps | 100% |
| SNPE Vectan BA6 1/2*ᴾ | <<locked>> | 100% | 28,558 psi | 77% | 1581 fps | 88.4% |
| SNPE Vectan BA7 1/2² | <<locked>> | 72% | 33,272 psi | 90% | 1549 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 64% | 31,923 psi | 86% | 1542 fps | 100% |
| Vihtavuori 3N38² | <<locked>> | 76% | 31,966 psi | 86% | 1608 fps | 97.3% |
| Vihtavuori N105 | <<locked>> | 80% | 32,822 psi | 89% | 1667 fps | 99.6% |
| Vihtavuori N110* | <<locked>> | 96% | 32,198 psi | 87% | 1680 fps | 87.5% |
| Vihtavuori N32C Tin Star | <<locked>> | 88% | 32,387 psi | 88% | 1299 fps | 100% |
| Vihtavuori N340² | <<locked>> | 64% | 33,373 psi | 90% | 1493 fps | 100% |
| Vihtavuori N350² | <<locked>> | 68% | 31,502 psi | 85% | 1529 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 64% | 31,546 psi | 85% | 1430 fps | 100% |
Start Load - Barrel Length: 6.5"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate No. 9*² | <<locked>> | 64% | 28,485 psi | 77% | 1558 fps | 87.7% |
| Accurate Solo 1250² | <<locked>> | 60% | 28,297 psi | 77% | 1365 fps | 100% |
| Accurate TCM*² | <<locked>> | 60% | 24,772 psi | 67% | 1473 fps | 86.5% |
| ADI AP 100² | <<locked>> | 60% | 20,276 psi | 55% | 1322 fps | 96% |
| ADI APS 450² | <<locked>> | 60% | 30,487 psi | 82% | 1273 fps | 100% |
| Alliant BE-86² | <<locked>> | 60% | 29,631 psi | 80% | 1371 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 64% | 21,799 psi | 59% | 1394 fps | 87.2% |
| Alliant Herco² | <<locked>> | 60% | 22,046 psi | 60% | 1309 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 60% | 29,472 psi | 80% | 1568 fps | 99% |
| Alliant RED DOT² | <<locked>> | 60% | 30,052 psi | 81% | 1319 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 29,689 psi | 80% | 1460 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 21,335 psi | 58% | 1198 fps | 100% |
| Hodgdon Clays² | <<locked>> | 60% | 25,817 psi | 70% | 1194 fps | 100% |
| Hodgdon TrailBoss² | <<locked>> | 60% | 11,429 psi | 31% | 896 fps | 100% |
| Lovex D037.2*² | <<locked>> | 60% | 25,121 psi | 68% | 1483 fps | 85.3% |
| Maxam CSB 1² | <<locked>> | 60% | 26,643 psi | 72% | 1332 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 29,762 psi | 80% | 1358 fps | 100% |
| Ramshot Enforcer*² | <<locked>> | 72% | 27,456 psi | 74% | 1565 fps | 85.1% |
| ReloadSwiss RS 14² | <<locked>> | 60% | 11,037 psi | 30% | 909 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 28,485 psi | 77% | 1434 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 60% | 26,832 psi | 73% | 1516 fps | 94.3% |
| Rottweil P 806² | <<locked>> | 60% | 25,527 psi | 69% | 1483 fps | 100% |
| Shooters World Heavy Pistol*² | <<locked>> | 60% | 25,121 psi | 68% | 1483 fps | 85.3% |
| SNPE Vectan A0² | <<locked>> | 60% | 26,803 psi | 72% | 1375 fps | 100% |
| SNPE Vectan BA6 1/2* | <<locked>> | 96% | 25,947 psi | 70% | 1526 fps | 86.5% |
| SNPE Vectan BA7 1/2² | <<locked>> | 60% | 23,757 psi | 64% | 1371 fps | 99.9% |
| Vihtavuori 3N37² | <<locked>> | 60% | 28,340 psi | 77% | 1480 fps | 100% |
| Vihtavuori 3N38*² | <<locked>> | 60% | 20,218 psi | 55% | 1342 fps | 90.7% |
| Vihtavuori N105*² | <<locked>> | 60% | 17,564 psi | 47% | 1319 fps | 92.3% |
| Vihtavuori N110* | <<locked>> | 92% | 28,601 psi | 77% | 1608 fps | 85.2% |
| Vihtavuori N32C Tin Star² | <<locked>> | 60% | 18,231 psi | 49% | 1056 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 29,718 psi | 80% | 1437 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 24,845 psi | 67% | 1407 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 60% | 28,398 psi | 77% | 1381 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 34 powders for .357 Auto Mag. loaded with the .356 | 135gr | X-TREME RNFP. Vihtavuori N110 delivers the highest muzzle velocity at 1,680 fps; across all powders the maximum-charge window runs from 1,178 fps to 1,680 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 6 of the 34 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (255 MPa), the top charges use 59–90 %, leaving at least 10 % headroom. Hodgdon TrailBoss, ReloadSwiss RS 14, SNPE Vectan BA6 1/2 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 No. 9, 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.