Load Specifications
Load data in caliber 9 mm Steyr with .355 | 125gr | Sierra Sports Master bullet and 12 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 |
|---|---|---|---|---|---|---|
| Alliant Herco² | <<locked>> | 72% | 16,070 psi | 82% | 1010 fps | 95.7% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 72% | 15,983 psi | 82% | 968 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 13,387 psi | 68% | 866 fps | 100% |
| Maxam CSB 1² | <<locked>> | 64% | 17,477 psi | 89% | 1004 fps | 99.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 11,734 psi | 60% | 850 fps | 99.9% |
| ReloadSwiss RS 20² | <<locked>> | 64% | 16,389 psi | 84% | 1040 fps | 97.9% |
| SNPE Vectan A0² | <<locked>> | 64% | 17,143 psi | 88% | 1001 fps | 96.2% |
| SNPE Vectan BA7 1/2*² | <<locked>> | 68% | 16,215 psi | 83% | 1004 fps | 87.3% |
| Vihtavuori 3N37*² | <<locked>> | 64% | 15,983 psi | 82% | 1024 fps | 88.5% |
| Vihtavuori N32C Tin Star | <<locked>> | 84% | 17,622 psi | 90% | 942 fps | 100% |
| Vihtavuori N350*² | <<locked>> | 72% | 17,695 psi | 90% | 1066 fps | 90.8% |
| Winchester AutoComp ² | <<locked>> | 64% | 17,666 psi | 90% | 1024 fps | 99.5% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 5"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Alliant Herco*² | <<locked>> | 60% | 11,734 psi | 60% | 883 fps | 90.7% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 11,197 psi | 57% | 850 fps | 99.9% |
| Hodgdon TrailBoss² | 2.4 gr | 60% | 6,063 psi | 31% | 623 fps | 97.4% |
| Maxam CSB 1² | <<locked>> | 60% | 15,519 psi | 79% | 958 fps | 99.3% |
| ReloadSwiss RS 14*² | 2.5 gr | 60% | 5,860 psi | 30% | 620 fps | 92.8% |
| ReloadSwiss RS 20² | <<locked>> | 60% | 14,605 psi | 75% | 994 fps | 96.6% |
| SNPE Vectan A0*² | <<locked>> | 60% | 15,302 psi | 78% | 958 fps | 94.7% |
| SNPE Vectan BA7 1/2*² | <<locked>> | 64% | 14,750 psi | 75% | 965 fps | 85.5% |
| Vihtavuori 3N37*² | <<locked>> | 60% | 14,460 psi | 74% | 984 fps | 86.6% |
| Vihtavuori N32C Tin Star² | <<locked>> | 60% | 10,022 psi | 51% | 771 fps | 100% |
| Vihtavuori N350*² | <<locked>> | 64% | 13,851 psi | 71% | 965 fps | 86.2% |
| Winchester AutoComp ² | <<locked>> | 60% | 15,867 psi | 81% | 981 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 12 powders for 9 mm Steyr loaded with the .355 | 125gr | Sierra Sports Master. Vihtavuori N350 delivers the highest muzzle velocity at 1,066 fps; across all powders the maximum-charge window runs from 850 fps to 1,066 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 3 of the 12 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (135 MPa), the top charges use 60–90 %, 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 .355 | 125gr | Sierra Sports Master they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, SNPE Vectan BA7 1/2, Vihtavuori 3N37, Vihtavuori N350 burn incompletely and react more sensitively to barrel length and temperature. Alliant Herco, Baschieri & Pellagri 102 Pistol, Hodgdon TrailBoss 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.