Load Specifications
Load data in caliber .38 Special with .355 | 90gr | Sierra Sports Master bullet and 10 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 |
|---|---|---|---|---|---|---|
| Accurate Solo 1250² | <<locked>> | 64% | 19,653 psi | 90% | 1234 fps | 98.4% |
| Alliant Herco*² | <<locked>> | 76% | 19,450 psi | 89% | 1250 fps | 93% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 76% | 19,406 psi | 89% | 1211 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 14,228 psi | 65% | 1043 fps | 100% |
| Maxam CSB 1² | <<locked>> | 64% | 18,797 psi | 86% | 1207 fps | 98% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 12,836 psi | 59% | 1024 fps | 98.1% |
| ReloadSwiss RS 20*² | <<locked>> | 64% | 17,941 psi | 82% | 1234 fps | 93.8% |
| SNPE Vectan A0*² | <<locked>> | 64% | 18,594 psi | 85% | 1207 fps | 92.5% |
| Vihtavuori N32C Tin Star | <<locked>> | 84% | 19,029 psi | 87% | 1152 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 64% | 19,522 psi | 90% | 1234 fps | 97.4% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 4"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate Solo 1250² | <<locked>> | 60% | 17,593 psi | 81% | 1181 fps | 97.2% |
| Alliant Herco*² | <<locked>> | 64% | 14,446 psi | 66% | 1102 fps | 87.5% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 12,473 psi | 57% | 1020 fps | 98.2% |
| Hodgdon TrailBoss*² | 3.7 gr | 60% | 6,672 psi | 31% | 755 fps | 93.5% |
| Maxam CSB 1² | <<locked>> | 60% | 16,433 psi | 76% | 1145 fps | 96.5% |
| ReloadSwiss RS 14*² | 3.7 gr | 60% | 6,121 psi | 28% | 732 fps | 86.8% |
| ReloadSwiss RS 20*² | <<locked>> | 60% | 15,708 psi | 72% | 1168 fps | 91.4% |
| SNPE Vectan A0*² | <<locked>> | 60% | 16,839 psi | 77% | 1158 fps | 90.7% |
| Vihtavuori N32C Tin Star² | <<locked>> | 60% | 10,979 psi | 50% | 938 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 60% | 17,347 psi | 80% | 1178 fps | 95.9% |
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 3 powders for .38 Special loaded with the .355 | 90gr | Sierra Sports Master. Vihtavuori N32C Tin Star delivers the highest muzzle velocity at 1,152 fps; across all powders the maximum-charge window runs from 1,024 fps to 1,152 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 3 of the 3 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (150 MPa), the top charges use 59–87 %, leaving at least 13 % 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 | 90gr | Sierra Sports Master they combine a high case fill with complete burn and sit in the upper velocity band. 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.