Load Specifications
Load data in caliber .38 Special with .355 | 125gr | Sierra Sports Master bullet and 7 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: 4"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Alliant Herco² | <<locked>> | 68% | 19,363 psi | 89% | 1056 fps | 97.6% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 68% | 18,840 psi | 87% | 994 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 16,926 psi | 78% | 922 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 15,519 psi | 71% | 919 fps | 100% |
| SNPE Vectan BA7 1/2*² | <<locked>> | 64% | 19,305 psi | 89% | 1053 fps | 90.3% |
| Vihtavuori N32C Tin Star² | <<locked>> | 76% | 19,406 psi | 89% | 951 fps | 100% |
| Vihtavuori N350*² | <<locked>> | 64% | 19,319 psi | 89% | 1070 fps | 91.8% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 4"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Alliant Herco*² | <<locked>> | 60% | 15,490 psi | 71% | 961 fps | 94.7% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 15,171 psi | 70% | 919 fps | 100% |
| Hodgdon TrailBoss² | 3.6 gr | 60% | 7,992 psi | 37% | 682 fps | 99.4% |
| ReloadSwiss RS 14² | 3.6 gr | 60% | 7,324 psi | 34% | 666 fps | 95.7% |
| SNPE Vectan BA7 1/2*² | <<locked>> | 60% | 17,187 psi | 79% | 1004 fps | 88.2% |
| Vihtavuori N32C Tin Star² | <<locked>> | 60% | 13,126 psi | 60% | 827 fps | 100% |
| Vihtavuori N350*² | <<locked>> | 60% | 17,027 psi | 78% | 1017 fps | 89.5% |
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 2 powders for .38 Special loaded with the .355 | 125gr | Sierra Sports Master. Hodgdon TrailBoss delivers the highest muzzle velocity at 922 fps; across all powders the maximum-charge window runs from 919 fps to 922 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 2 of the 2 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (150 MPa), the top charges use 71–78 %, leaving at least 22 % 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 .38 Special with the .355 | 125gr | Sierra Sports Master they combine a high case fill with complete burn and sit in the upper velocity band. 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.