Load Specifications
Load data in caliber .38 Special with .357 | 158gr | Hornady FP XTP bullet and 8 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% | 19,450 psi | 89% | 919 fps | 99.2% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 68% | 18,985 psi | 87% | 856 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 17,622 psi | 81% | 801 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 15,708 psi | 72% | 791 fps | 100% |
| Rottweil P 806*² | <<locked>> | 64% | 17,158 psi | 79% | 942 fps | 89.9% |
| SNPE Vectan BA7 1/2*² | <<locked>> | 64% | 19,609 psi | 90% | 922 fps | 93.7% |
| Vihtavuori N32C Tin Star² | <<locked>> | 72% | 17,811 psi | 82% | 787 fps | 100% |
| Vihtavuori N350² | <<locked>> | 64% | 19,464 psi | 89% | 935 fps | 95% |
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 Herco² | <<locked>> | 60% | 15,722 psi | 72% | 840 fps | 97.4% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 15,534 psi | 71% | 797 fps | 100% |
| Hodgdon TrailBoss² | 2.9 gr | 60% | 7,948 psi | 37% | 584 fps | 100% |
| ReloadSwiss RS 14² | 3 gr | 60% | 7,629 psi | 35% | 587 fps | 98.4% |
| Rottweil P 806*² | <<locked>> | 60% | 14,736 psi | 68% | 883 fps | 86.8% |
| SNPE Vectan BA7 1/2*² | <<locked>> | 60% | 16,998 psi | 78% | 869 fps | 91.4% |
| Vihtavuori N32C Tin Star² | <<locked>> | 60% | 13,184 psi | 61% | 705 fps | 100% |
| Vihtavuori N350*² | <<locked>> | 60% | 17,202 psi | 79% | 889 fps | 93.1% |
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 8 powders for .38 Special loaded with the .357 | 158gr | Hornady FP XTP. Rottweil P 806 delivers the highest muzzle velocity at 942 fps; across all powders the maximum-charge window runs from 787 fps to 942 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 2 of the 8 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (150 MPa), the top charges use 72–90 %, 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 .38 Special with the .357 | 158gr | Hornady FP XTP 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 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.