Load Specifications
Load data in caliber 9 mm Steyr with .357 | 158gr | Ares RNBB bullet and 17 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon TrailBoss and ReloadSwiss RS 14.
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: 5"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate Solo 1250² | <<locked>> | 64% | 17,564 psi | 90% | 833 fps | 100% |
| Alliant Herco² | <<locked>> | 76% | 16,911 psi | 86% | 856 fps | 97.3% |
| Alliant UNIQUE² | <<locked>> | 64% | 16,810 psi | 86% | 853 fps | 97.2% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 76% | 16,317 psi | 83% | 807 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 12,604 psi | 64% | 699 fps | 100% |
| Maxam CSB 1² | <<locked>> | 68% | 17,709 psi | 90% | 830 fps | 100% |
| Maxam CSB 2² | <<locked>> | 64% | 16,302 psi | 83% | 830 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 10,994 psi | 56% | 686 fps | 100% |
| ReloadSwiss RS 20² | <<locked>> | 68% | 16,911 psi | 86% | 873 fps | 99% |
| Rottweil P 806* | <<locked>> | 80% | 15,853 psi | 81% | 938 fps | 88.6% |
| SNPE Vectan A0² | <<locked>> | 64% | 16,346 psi | 83% | 810 fps | 96.5% |
| SNPE Vectan BA7 1/2*² | <<locked>> | 72% | 16,708 psi | 85% | 843 fps | 89.3% |
| Vihtavuori 3N37*² | <<locked>> | 68% | 17,158 psi | 88% | 876 fps | 91.3% |
| Vihtavuori N32C Tin Star | <<locked>> | 84% | 16,882 psi | 86% | 761 fps | 100% |
| Vihtavuori N340² | <<locked>> | 64% | 17,361 psi | 89% | 850 fps | 97.8% |
| Vihtavuori N350*² | <<locked>> | 72% | 16,186 psi | 83% | 856 fps | 90.8% |
| Winchester AutoComp ² | <<locked>> | 64% | 16,955 psi | 87% | 833 fps | 99.7% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 5"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate Solo 1250² | <<locked>> | 60% | 15,708 psi | 80% | 801 fps | 99.8% |
| Alliant Herco*² | <<locked>> | 60% | 11,124 psi | 57% | 719 fps | 91.4% |
| Alliant UNIQUE² | <<locked>> | 60% | 15,156 psi | 77% | 820 fps | 96% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 10,689 psi | 55% | 692 fps | 100% |
| Hodgdon TrailBoss² | 1.8 gr | 60% | 5,947 psi | 30% | 512 fps | 98.1% |
| Maxam CSB 1² | <<locked>> | 60% | 14,286 psi | 73% | 768 fps | 99.3% |
| Maxam CSB 2² | <<locked>> | 60% | 14,518 psi | 74% | 801 fps | 100% |
| ReloadSwiss RS 14*² | 1.8 gr | 60% | 5,453 psi | 28% | 499 fps | 93.1% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 13,053 psi | 67% | 791 fps | 96.3% |
| Rottweil P 806*² | <<locked>> | 76% | 14,127 psi | 72% | 899 fps | 86.4% |
| SNPE Vectan A0² | <<locked>> | 60% | 14,794 psi | 76% | 778 fps | 95.2% |
| SNPE Vectan BA7 1/2*² | <<locked>> | 64% | 13,460 psi | 69% | 771 fps | 85.3% |
| Vihtavuori 3N37*² | <<locked>> | 60% | 13,039 psi | 67% | 784 fps | 86.4% |
| Vihtavuori N32C Tin Star² | <<locked>> | 60% | 9,340 psi | 48% | 620 fps | 100% |
| Vihtavuori N340² | <<locked>> | 60% | 15,664 psi | 80% | 817 fps | 96.7% |
| Vihtavuori N350*² | <<locked>> | 64% | 12,807 psi | 65% | 778 fps | 86.4% |
| Winchester AutoComp ² | <<locked>> | 60% | 14,721 psi | 75% | 791 fps | 98.9% |
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 17 powders for 9 mm Steyr loaded with the .357 | 158gr | Ares RNBB. Rottweil P 806 delivers the highest muzzle velocity at 938 fps; across all powders the maximum-charge window runs from 686 fps to 938 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 4 of the 17 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (135 MPa), the top charges use 56–90 %, 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. Hodgdon TrailBoss, ReloadSwiss RS 14 rank at the top here: for 9 mm Steyr with the .357 | 158gr | Ares RNBB they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Rottweil P 806, SNPE Vectan BA7 1/2, Vihtavuori 3N37 burn incompletely and react more sensitively to barrel length and temperature. Accurate Solo 1250, Alliant Herco, Alliant UNIQUE 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.