Load Specifications
Load data in caliber .38 Special with .357 | 93gr | MEN PEP bullet and 17 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N32C Tin Star and Hodgdon TrailBoss.
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% | 17,970 psi | 83% | 1155 fps | 97.2% |
| Alliant BE-86² | <<locked>> | 64% | 18,478 psi | 85% | 1168 fps | 99.1% |
| Alliant Herco* | <<locked>> | 80% | 19,479 psi | 90% | 1217 fps | 92.7% |
| Alliant UNIQUE*² | <<locked>> | 64% | 17,535 psi | 81% | 1175 fps | 90.9% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 80% | 19,145 psi | 88% | 1175 fps | 100% |
| Hodgdon Clays² | <<locked>> | 64% | 19,334 psi | 89% | 1083 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 12,821 psi | 59% | 974 fps | 99.9% |
| Maxam CSB 1² | <<locked>> | 68% | 18,855 psi | 87% | 1175 fps | 97.9% |
| Maxam CSB 2² | <<locked>> | 68% | 19,116 psi | 88% | 1207 fps | 100% |
| Maxam CSB 3² | <<locked>> | 64% | 19,116 psi | 88% | 1171 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 11,574 psi | 53% | 955 fps | 96.9% |
| ReloadSwiss RS 20*² | <<locked>> | 68% | 17,825 psi | 82% | 1201 fps | 93.5% |
| SNPE Vectan A0*² | <<locked>> | 68% | 19,072 psi | 88% | 1181 fps | 92.4% |
| Somchem MS200*² | <<locked>> | 64% | 18,869 psi | 87% | 1188 fps | 93.6% |
| Vihtavuori N32C Tin Star | <<locked>> | 88% | 18,405 psi | 85% | 1106 fps | 100% |
| Vihtavuori N340*² | <<locked>> | 64% | 17,941 psi | 82% | 1168 fps | 91.8% |
| Winchester AutoComp ² | <<locked>> | 68% | 19,348 psi | 89% | 1198 fps | 97.1% |
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% | 15,751 psi | 72% | 1096 fps | 95.6% |
| Alliant BE-86² | <<locked>> | 60% | 15,925 psi | 73% | 1102 fps | 97.8% |
| Alliant Herco*² | <<locked>> | 68% | 14,156 psi | 65% | 1063 fps | 86.8% |
| Alliant UNIQUE*² | <<locked>> | 60% | 15,548 psi | 71% | 1112 fps | 88.6% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 10,994 psi | 51% | 945 fps | 96.6% |
| Hodgdon Clays² | <<locked>> | 60% | 17,390 psi | 80% | 1040 fps | 100% |
| Hodgdon TrailBoss*² | 3 gr | 60% | 5,860 psi | 27% | 692 fps | 91.2% |
| Maxam CSB 1*² | <<locked>> | 60% | 14,649 psi | 67% | 1060 fps | 94.7% |
| Maxam CSB 2² | <<locked>> | 60% | 15,200 psi | 70% | 1106 fps | 98.9% |
| Maxam CSB 3² | <<locked>> | 60% | 17,303 psi | 80% | 1125 fps | 99.4% |
| ReloadSwiss RS 14*² | <<locked>> | 64% | 6,034 psi | 28% | 705 fps | 86.1% |
| ReloadSwiss RS 20*² | <<locked>> | 60% | 13,982 psi | 64% | 1086 fps | 88.9% |
| SNPE Vectan A0*² | <<locked>> | 60% | 15,084 psi | 69% | 1066 fps | 88.2% |
| Somchem MS200*² | <<locked>> | 60% | 16,795 psi | 77% | 1129 fps | 91.6% |
| Vihtavuori N32C Tin Star² | 4.1 gr | 60% | 9,544 psi | 44% | 866 fps | 99.9% |
| Vihtavuori N340*² | <<locked>> | 60% | 15,867 psi | 73% | 1109 fps | 89.6% |
| Winchester AutoComp *² | <<locked>> | 60% | 15,519 psi | 71% | 1093 fps | 94.1% |
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 .38 Special loaded with the .357 | 93gr | MEN PEP. Alliant Herco delivers the highest muzzle velocity at 1,217 fps; across all powders the maximum-charge window runs from 955 fps to 1,217 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 5 of the 17 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (150 MPa), the top charges use 53–90 %, 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. Vihtavuori N32C Tin Star, Hodgdon TrailBoss rank at the top here: for .38 Special with the .357 | 93gr | MEN PEP they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Herco, Alliant UNIQUE, ReloadSwiss RS 20 burn incompletely and react more sensitively to barrel length and temperature. Accurate Solo 1250, Alliant BE-86, Alliant Herco 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.