Load Specifications
Load data in caliber .357 Auto Mag. with .358 | 148gr | Rim Rock SWC 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 No. 9*² | <<locked>> | 68% | 32,314 psi | 87% | 1572 fps | 91.5% |
| Accurate Solo 1250² | <<locked>> | 64% | 31,212 psi | 84% | 1345 fps | 100% |
| Accurate TCM*² | <<locked>> | 68% | 32,372 psi | 88% | 1568 fps | 92.7% |
| ADI AP 100² | <<locked>> | 76% | 30,690 psi | 83% | 1486 fps | 99.9% |
| ADI APS 450² | <<locked>> | 64% | 33,069 psi | 89% | 1250 fps | 100% |
| ADI AS 30² | <<locked>> | 64% | 33,257 psi | 90% | 1286 fps | 100% |
| Alliant 2400*² | <<locked>> | 76% | 31,691 psi | 86% | 1581 fps | 88.3% |
| Alliant BE-86² | <<locked>> | 64% | 32,242 psi | 87% | 1345 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 76% | 30,081 psi | 81% | 1526 fps | 94.2% |
| Alliant Herco² | <<locked>> | 76% | 32,039 psi | 87% | 1427 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 64% | 32,764 psi | 89% | 1562 fps | 99.9% |
| Alliant RED DOT² | <<locked>> | 64% | 32,329 psi | 87% | 1293 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 64% | 32,358 psi | 87% | 1437 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 76% | 30,676 psi | 83% | 1296 fps | 100% |
| Hodgdon LilGun* | <<locked>> | 88% | 32,126 psi | 87% | 1663 fps | 89.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 22,292 psi | 60% | 1112 fps | 100% |
| Lovex D037.2*² | <<locked>> | 68% | 32,779 psi | 89% | 1581 fps | 91.7% |
| Maxam CSB 1² | <<locked>> | 68% | 32,474 psi | 88% | 1358 fps | 100% |
| Maxam CSB 2² | <<locked>> | 64% | 32,880 psi | 89% | 1355 fps | 100% |
| Maxam CSB 3² | <<locked>> | 64% | 32,735 psi | 89% | 1339 fps | 100% |
| Ramshot Enforcer*² | <<locked>> | 76% | 30,574 psi | 83% | 1572 fps | 88.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 20,755 psi | 56% | 1125 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 64% | 31,343 psi | 85% | 1411 fps | 100% |
| ReloadSwiss RS 24² | <<locked>> | 64% | 30,095 psi | 81% | 1522 fps | 97% |
| Rottweil P 806² | <<locked>> | 68% | 31,894 psi | 86% | 1539 fps | 100% |
| Shooters World Heavy Pistol*² | <<locked>> | 68% | 32,779 psi | 89% | 1581 fps | 91.7% |
| SNPE Vectan A0² | <<locked>> | 68% | 33,098 psi | 89% | 1411 fps | 100% |
| SNPE Vectan BA6 1/2*ᴾ | <<locked>> | 100% | 28,268 psi | 76% | 1519 fps | 90% |
| SNPE Vectan BA7 1/2² | <<locked>> | 72% | 32,967 psi | 89% | 1473 fps | 100% |
| Somchem MS200² | <<locked>> | 64% | 32,808 psi | 89% | 1414 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 64% | 31,430 psi | 85% | 1467 fps | 100% |
| Vihtavuori 3N38² | <<locked>> | 76% | 31,633 psi | 86% | 1539 fps | 98.1% |
| Vihtavuori N105 | <<locked>> | 80% | 32,648 psi | 88% | 1591 fps | 99.9% |
| Vihtavuori N110* | <<locked>> | 96% | 31,604 psi | 85% | 1604 fps | 88.9% |
| Vihtavuori N32C Tin Star | <<locked>> | 88% | 31,763 psi | 86% | 1234 fps | 100% |
| Vihtavuori N340² | <<locked>> | 64% | 33,228 psi | 90% | 1424 fps | 100% |
| Vihtavuori N350² | <<locked>> | 68% | 31,038 psi | 84% | 1453 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 64% | 30,748 psi | 83% | 1355 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. 9*² | <<locked>> | 60% | 23,844 psi | 64% | 1398 fps | 85.9% |
| Accurate Solo 1250² | <<locked>> | 60% | 27,905 psi | 75% | 1296 fps | 100% |
| Accurate TCM*² | <<locked>> | 60% | 24,163 psi | 65% | 1401 fps | 87.6% |
| ADI AP 100² | <<locked>> | 60% | 19,377 psi | 52% | 1247 fps | 96.4% |
| ADI APS 450² | <<locked>> | 60% | 30,197 psi | 82% | 1207 fps | 100% |
| ADI AS 30² | <<locked>> | 60% | 30,240 psi | 82% | 1243 fps | 100% |
| Alliant 2400*² | <<locked>> | 72% | 27,659 psi | 75% | 1503 fps | 85.7% |
| Alliant BE-86² | <<locked>> | 60% | 28,732 psi | 78% | 1296 fps | 100% |
| Alliant BLUE DOT*² | <<locked>> | 60% | 18,463 psi | 50% | 1253 fps | 85.5% |
| Alliant Herco² | <<locked>> | 60% | 21,205 psi | 57% | 1237 fps | 100% |
| Alliant POWER PISTOL² | <<locked>> | 60% | 28,877 psi | 78% | 1490 fps | 99.4% |
| Alliant RED DOT² | <<locked>> | 60% | 29,298 psi | 79% | 1247 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 28,645 psi | 77% | 1378 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 20,465 psi | 55% | 1132 fps | 100% |
| Hodgdon LilGun* | <<locked>> | 84% | 27,949 psi | 76% | 1581 fps | 86.2% |
| Hodgdon TrailBoss² | 5.1 gr | 60% | 10,327 psi | 28% | 840 fps | 100% |
| Lovex D037.2*² | <<locked>> | 60% | 24,540 psi | 66% | 1414 fps | 86.4% |
| Maxam CSB 1² | <<locked>> | 60% | 26,121 psi | 71% | 1263 fps | 100% |
| Maxam CSB 2² | <<locked>> | 60% | 29,501 psi | 80% | 1306 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 29,327 psi | 79% | 1289 fps | 100% |
| Ramshot Enforcer*² | <<locked>> | 72% | 26,687 psi | 72% | 1493 fps | 86.2% |
| ReloadSwiss RS 14² | 5.2 gr | 60% | 9,805 psi | 27% | 846 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 27,659 psi | 75% | 1355 fps | 100% |
| ReloadSwiss RS 24² | <<locked>> | 60% | 26,310 psi | 71% | 1444 fps | 95.2% |
| Rottweil P 806² | <<locked>> | 60% | 24,105 psi | 65% | 1398 fps | 100% |
| Shooters World Heavy Pistol*² | <<locked>> | 60% | 24,540 psi | 66% | 1414 fps | 86.4% |
| SNPE Vectan A0² | <<locked>> | 60% | 26,513 psi | 72% | 1306 fps | 100% |
| SNPE Vectan BA6 1/2* | <<locked>> | 92% | 22,684 psi | 61% | 1394 fps | 85.5% |
| SNPE Vectan BA7 1/2² | <<locked>> | 60% | 23,351 psi | 63% | 1309 fps | 100% |
| Somchem MS200² | <<locked>> | 60% | 29,588 psi | 80% | 1365 fps | 100% |
| Vihtavuori 3N37² | <<locked>> | 60% | 27,601 psi | 75% | 1401 fps | 100% |
| Vihtavuori 3N38*² | <<locked>> | 60% | 19,174 psi | 52% | 1266 fps | 91.2% |
| Vihtavuori N105*² | <<locked>> | 60% | 16,375 psi | 44% | 1237 fps | 92.4% |
| Vihtavuori N110* | <<locked>> | 92% | 27,804 psi | 75% | 1529 fps | 86.3% |
| Vihtavuori N32C Tin Star² | 6.9 gr | 60% | 17,376 psi | 47% | 1001 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 29,399 psi | 79% | 1365 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 23,989 psi | 65% | 1332 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 60% | 27,470 psi | 74% | 1306 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 .358 | 148gr | Rim Rock SWC. Hodgdon LilGun delivers the highest muzzle velocity at 1,663 fps; across all powders the maximum-charge window runs from 1,112 fps to 1,663 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 7 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 56–90 %, 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. Vihtavuori N32C Tin Star, ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for .357 Auto Mag. with the .358 | 148gr | Rim Rock SWC they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate No. 9, Accurate TCM, Alliant 2400 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.