Load Specifications
Load data in caliber .357 Mag. with .358 | 125gr | Rim Rock RNFP Cowboy bullet and 65 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N105, ADI AP 100 and SNPE Vectan BA7 1/2.
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.
A valid access license is required to use the Personalized Load Calculator.
You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate No. 2² | <<locked>> | 72% | 35,027 psi | 81% | 1453 fps | 100% |
| Accurate No. 7*² | <<locked>> | 76% | 37,985 psi | 87% | 1647 fps | 92.5% |
| Accurate Solo 1000² | <<locked>> | 76% | 37,289 psi | 86% | 1378 fps | 100% |
| Accurate Solo 1250 | <<locked>> | 80% | 36,666 psi | 84% | 1434 fps | 100% |
| Accurate TCM* | <<locked>> | 84% | 37,666 psi | 87% | 1624 fps | 88% |
| ADI AP 100 | <<locked>> | 96% | 37,072 psi | 85% | 1581 fps | 98.9% |
| ADI AP 70N² | <<locked>> | 68% | 39,102 psi | 90% | 1480 fps | 100% |
| ADI APS 350² | <<locked>> | 76% | 38,957 psi | 90% | 1283 fps | 100% |
| ADI APS 450² | <<locked>> | 76% | 37,724 psi | 87% | 1306 fps | 100% |
| ADI AS 30² | <<locked>> | 76% | 36,651 psi | 84% | 1339 fps | 100% |
| ADI AS 50N² | <<locked>> | 72% | 36,608 psi | 84% | 1388 fps | 100% |
| Alliant BE-86 | <<locked>> | 80% | 38,754 psi | 89% | 1440 fps | 100% |
| Alliant BLUE DOT* | <<locked>> | 96% | 35,708 psi | 82% | 1601 fps | 90.3% |
| Alliant BULLSEYE² | <<locked>> | 72% | 38,406 psi | 88% | 1532 fps | 100% |
| Alliant Green Dot² | <<locked>> | 76% | 36,912 psi | 85% | 1394 fps | 100% |
| Alliant Herco | <<locked>> | 96% | 38,305 psi | 88% | 1529 fps | 100% |
| Alliant POWER PISTOL | <<locked>> | 80% | 37,985 psi | 87% | 1640 fps | 98.6% |
| Alliant RED DOT | <<locked>> | 80% | 38,334 psi | 88% | 1381 fps | 100% |
| Alliant Sport Pistol² | <<locked>> | 64% | 35,694 psi | 82% | 1499 fps | 100% |
| Alliant UNIQUE | <<locked>> | 80% | 36,985 psi | 85% | 1519 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 76% | 36,782 psi | 85% | 1375 fps | 100% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 96% | 38,101 psi | 88% | 1401 fps | 100% |
| Baschieri & Pellagri 103 Pistol² | <<locked>> | 72% | 37,318 psi | 86% | 1401 fps | 100% |
| Hodgdon CFE Pistol² | <<locked>> | 76% | 37,028 psi | 85% | 1450 fps | 100% |
| Hodgdon Clays² | <<locked>> | 72% | 36,027 psi | 83% | 1263 fps | 100% |
| Hodgdon HS-6² | <<locked>> | 64% | 35,027 psi | 81% | 1526 fps | 99.9% |
| Hodgdon Longshot² | <<locked>> | 64% | 38,841 psi | 89% | 1575 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 17,405 psi | 40% | 1040 fps | 100% |
| Hodgdon Universal² | <<locked>> | 76% | 39,102 psi | 90% | 1480 fps | 100% |
| Lovex D037.1*² | <<locked>> | 76% | 37,985 psi | 87% | 1647 fps | 92.5% |
| Lovex S011² | <<locked>> | 64% | 35,143 psi | 81% | 1385 fps | 100% |
| Lovex S020² | <<locked>> | 72% | 37,072 psi | 85% | 1473 fps | 100% |
| Maxam CSB 1 | <<locked>> | 84% | 37,681 psi | 87% | 1440 fps | 100% |
| Maxam CSB 2 | <<locked>> | 80% | 37,826 psi | 87% | 1440 fps | 100% |
| Maxam CSB 3 | <<locked>> | 80% | 38,174 psi | 88% | 1421 fps | 100% |
| Maxam CSB 4² | <<locked>> | 76% | 37,652 psi | 87% | 1391 fps | 100% |
| Maxam CSB 5² | <<locked>> | 72% | 37,652 psi | 87% | 1339 fps | 100% |
| Ramshot Silhouette² | <<locked>> | 64% | 35,070 psi | 81% | 1493 fps | 100% |
| ReloadSwiss RS 12² | <<locked>> | 68% | 36,172 psi | 83% | 1401 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 15,954 psi | 37% | 1043 fps | 100% |
| ReloadSwiss RS 20 | <<locked>> | 80% | 36,071 psi | 83% | 1496 fps | 100% |
| ReloadSwiss RS 24* | <<locked>> | 80% | 35,389 psi | 81% | 1594 fps | 93.7% |
| Rottweil P 801² | <<locked>> | 64% | 36,390 psi | 84% | 1371 fps | 100% |
| Rottweil P 806 | <<locked>> | 84% | 34,882 psi | 80% | 1604 fps | 100% |
| Shooters World Major Pistol*² | <<locked>> | 76% | 37,985 psi | 87% | 1647 fps | 92.5% |
| SNPE Vectan A0 | <<locked>> | 84% | 37,739 psi | 87% | 1483 fps | 100% |
| SNPE Vectan A1² | <<locked>> | 76% | 38,493 psi | 88% | 1434 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 76% | 37,536 psi | 86% | 1447 fps | 100% |
| SNPE Vectan BA10² | <<locked>> | 72% | 38,566 psi | 89% | 1316 fps | 100% |
| SNPE Vectan BA7 1/2 | <<locked>> | 88% | 37,550 psi | 86% | 1542 fps | 100% |
| SNPE Vectan BA9 1/2² | <<locked>> | 76% | 37,028 psi | 85% | 1444 fps | 100% |
| SNPE Vectan SP 2² | <<locked>> | 76% | 38,508 psi | 89% | 1654 fps | 99.5% |
| Somchem MP200² | <<locked>> | 72% | 35,621 psi | 82% | 1493 fps | 100% |
| Somchem MS200 | <<locked>> | 80% | 38,305 psi | 88% | 1499 fps | 100% |
| Somchem S221² | <<locked>> | 68% | 36,114 psi | 83% | 1581 fps | 96.5% |
| Vihtavuori 3N37 | <<locked>> | 80% | 36,738 psi | 84% | 1555 fps | 100% |
| Vihtavuori 3N38* | <<locked>> | 92% | 36,680 psi | 84% | 1604 fps | 94.9% |
| Vihtavuori N105ᴾ | <<locked>> | 100% | 36,680 psi | 84% | 1660 fps | 98.2% |
| Vihtavuori N320² | <<locked>> | 72% | 35,723 psi | 82% | 1375 fps | 100% |
| Vihtavuori N32C Tin Starᴾ | <<locked>> | 100% | 37,289 psi | 86% | 1306 fps | 100% |
| Vihtavuori N330² | <<locked>> | 76% | 38,798 psi | 89% | 1473 fps | 100% |
| Vihtavuori N340 | <<locked>> | 80% | 38,595 psi | 89% | 1506 fps | 100% |
| Vihtavuori N350 | <<locked>> | 84% | 37,565 psi | 86% | 1558 fps | 100% |
| Winchester 231² | <<locked>> | 64% | 37,927 psi | 87% | 1437 fps | 100% |
| Winchester AutoComp | <<locked>> | 80% | 36,477 psi | 84% | 1447 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate No. 2² | <<locked>> | 60% | 24,192 psi | 56% | 1283 fps | 100% |
| Accurate No. 7*² | <<locked>> | 68% | 28,732 psi | 66% | 1490 fps | 87.8% |
| Accurate Solo 1000² | <<locked>> | 60% | 25,034 psi | 58% | 1204 fps | 100% |
| Accurate Solo 1250² | <<locked>> | 60% | 21,640 psi | 50% | 1204 fps | 100% |
| Accurate TCM* | <<locked>> | 80% | 32,590 psi | 75% | 1542 fps | 85.3% |
| ADI AP 100*² | 8 gr | 64% | 16,056 psi | 37% | 1142 fps | 86.9% |
| ADI AP 70N² | <<locked>> | 60% | 30,661 psi | 70% | 1365 fps | 100% |
| ADI APS 350² | <<locked>> | 60% | 27,151 psi | 62% | 1129 fps | 100% |
| ADI APS 450² | <<locked>> | 60% | 26,121 psi | 60% | 1148 fps | 100% |
| ADI AS 30² | <<locked>> | 60% | 24,961 psi | 57% | 1175 fps | 100% |
| ADI AS 50N² | <<locked>> | 60% | 26,629 psi | 61% | 1247 fps | 100% |
| Alliant BE-86² | <<locked>> | 60% | 22,278 psi | 51% | 1207 fps | 100% |
| Alliant BLUE DOT* | <<locked>> | 88% | 29,341 psi | 67% | 1490 fps | 86.9% |
| Alliant BULLSEYE² | <<locked>> | 60% | 27,688 psi | 64% | 1371 fps | 100% |
| Alliant Green Dot² | <<locked>> | 60% | 24,265 psi | 56% | 1207 fps | 100% |
| Alliant Herco² | <<locked>> | 60% | 15,867 psi | 36% | 1115 fps | 98.9% |
| Alliant POWER PISTOL*² | <<locked>> | 60% | 20,740 psi | 48% | 1302 fps | 90.5% |
| Alliant RED DOT² | <<locked>> | 60% | 24,047 psi | 55% | 1178 fps | 100% |
| Alliant Sport Pistol² | <<locked>> | 60% | 31,198 psi | 72% | 1430 fps | 100% |
| Alliant UNIQUE² | <<locked>> | 60% | 21,785 psi | 50% | 1263 fps | 100% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 24,105 psi | 55% | 1201 fps | 100% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 15,577 psi | 36% | 1050 fps | 100% |
| Baschieri & Pellagri 103 Pistol² | <<locked>> | 60% | 25,918 psi | 60% | 1250 fps | 100% |
| Hodgdon CFE Pistol² | <<locked>> | 60% | 23,801 psi | 55% | 1253 fps | 100% |
| Hodgdon Clays² | <<locked>> | 60% | 27,586 psi | 63% | 1148 fps | 100% |
| Hodgdon HS-6² | <<locked>> | 60% | 30,589 psi | 70% | 1457 fps | 99.3% |
| Hodgdon Longshot² | <<locked>> | 60% | 33,939 psi | 78% | 1503 fps | 100% |
| Hodgdon TrailBoss² | <<locked>> | 60% | 8,137 psi | 19% | 781 fps | 100% |
| Hodgdon Universal² | <<locked>> | 60% | 25,860 psi | 59% | 1289 fps | 100% |
| Lovex D037.1*² | <<locked>> | 68% | 28,732 psi | 66% | 1490 fps | 87.8% |
| Lovex S011² | <<locked>> | 60% | 31,850 psi | 73% | 1342 fps | 100% |
| Lovex S020² | <<locked>> | 60% | 25,077 psi | 58% | 1299 fps | 100% |
| Maxam CSB 1² | <<locked>> | 60% | 20,189 psi | 46% | 1168 fps | 100% |
| Maxam CSB 2² | <<locked>> | 60% | 22,060 psi | 51% | 1211 fps | 100% |
| Maxam CSB 3² | <<locked>> | 60% | 22,858 psi | 53% | 1198 fps | 100% |
| Maxam CSB 4² | <<locked>> | 60% | 24,671 psi | 57% | 1207 fps | 100% |
| Maxam CSB 5² | <<locked>> | 60% | 27,760 psi | 64% | 1207 fps | 100% |
| Ramshot Silhouette² | <<locked>> | 60% | 30,371 psi | 70% | 1421 fps | 100% |
| ReloadSwiss RS 12² | <<locked>> | 60% | 29,269 psi | 67% | 1312 fps | 100% |
| ReloadSwiss RS 14² | <<locked>> | 60% | 7,455 psi | 17% | 768 fps | 99.3% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 20,262 psi | 47% | 1240 fps | 100% |
| ReloadSwiss RS 24*² | <<locked>> | 68% | 24,105 psi | 55% | 1378 fps | 87.1% |
| Rottweil P 801² | <<locked>> | 60% | 32,503 psi | 75% | 1322 fps | 100% |
| Rottweil P 806*² | <<locked>> | 60% | 14,953 psi | 34% | 1184 fps | 90.9% |
| Shooters World Major Pistol*² | <<locked>> | 68% | 28,732 psi | 66% | 1490 fps | 87.8% |
| SNPE Vectan A0² | <<locked>> | 60% | 20,523 psi | 47% | 1201 fps | 100% |
| SNPE Vectan A1² | <<locked>> | 60% | 25,019 psi | 57% | 1247 fps | 100% |
| SNPE Vectan BA 9² | <<locked>> | 60% | 24,178 psi | 56% | 1250 fps | 100% |
| SNPE Vectan BA10² | <<locked>> | 60% | 29,022 psi | 67% | 1191 fps | 100% |
| SNPE Vectan BA7 1/2*² | 8 gr | 60% | 17,448 psi | 40% | 1161 fps | 94.2% |
| SNPE Vectan BA9 1/2² | <<locked>> | 60% | 23,888 psi | 55% | 1250 fps | 100% |
| SNPE Vectan SP 2*² | <<locked>> | 60% | 22,756 psi | 52% | 1365 fps | 94.1% |
| Somchem MP200² | <<locked>> | 60% | 25,063 psi | 58% | 1322 fps | 100% |
| Somchem MS200² | <<locked>> | 60% | 22,771 psi | 52% | 1257 fps | 100% |
| Somchem S221*² | <<locked>> | 60% | 27,354 psi | 63% | 1427 fps | 92.7% |
| Vihtavuori 3N37² | <<locked>> | 60% | 20,001 psi | 46% | 1253 fps | 97% |
| Vihtavuori 3N38*² | <<locked>> | 76% | 22,916 psi | 53% | 1348 fps | 87.2% |
| Vihtavuori N105*² | 10.8 gr | 76% | 17,941 psi | 41% | 1280 fps | 86.7% |
| Vihtavuori N320² | <<locked>> | 60% | 26,121 psi | 60% | 1240 fps | 100% |
| Vihtavuori N32C Tin Star² | <<locked>> | 60% | 15,345 psi | 35% | 978 fps | 100% |
| Vihtavuori N330² | <<locked>> | 60% | 24,279 psi | 56% | 1270 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 21,799 psi | 50% | 1247 fps | 100% |
| Vihtavuori N350² | <<locked>> | 60% | 18,144 psi | 42% | 1204 fps | 96.2% |
| Winchester 231² | <<locked>> | 60% | 33,272 psi | 76% | 1378 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 60% | 20,914 psi | 48% | 1204 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 13 powders for .357 Mag. loaded with the .358 | 125gr | Rim Rock RNFP Cowboy. Vihtavuori N105 delivers the highest muzzle velocity at 1,660 fps; across all powders the maximum-charge window runs from 1,040 fps to 1,660 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 13 of the 13 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (300 MPa), the top charges use 37–88 %, leaving at least 12 % headroom. Hodgdon TrailBoss, ReloadSwiss RS 14, Vihtavuori N105 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 N105, ADI AP 100, SNPE Vectan BA7 1/2 rank at the top here: for .357 Mag. with the .358 | 125gr | Rim Rock RNFP Cowboy they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Vihtavuori 3N38 burn incompletely and react more sensitively to barrel length and temperature. 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.