Load Specifications
Load data in caliber .38 Spl. Wad Cut. with .357 | 148gr | H&N WC HS 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: 4"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate Solo 1250² | <<locked>> | 64% | 15,447 psi | 89% | 807 fps | 98.8% |
| Alliant Herco*² | <<locked>> | 76% | 14,997 psi | 86% | 823 fps | 93.7% |
| Alliant UNIQUE*² | <<locked>> | 64% | 15,142 psi | 87% | 830 fps | 93.8% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 76% | 14,678 psi | 84% | 791 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 10,617 psi | 61% | 676 fps | 100% |
| Maxam CSB 1² | <<locked>> | 64% | 14,750 psi | 85% | 791 fps | 98.5% |
| Maxam CSB 2² | <<locked>> | 64% | 14,562 psi | 84% | 817 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 9,340 psi | 54% | 663 fps | 98.2% |
| ReloadSwiss RS 20² | <<locked>> | 68% | 15,403 psi | 89% | 850 fps | 96.4% |
| SNPE Vectan A0*² | <<locked>> | 64% | 15,200 psi | 87% | 797 fps | 93.6% |
| Vihtavuori N32C Tin Star | <<locked>> | 84% | 15,214 psi | 87% | 758 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 64% | 15,287 psi | 88% | 814 fps | 98% |
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% | 13,764 psi | 79% | 771 fps | 97.8% |
| Alliant Herco*² | <<locked>> | 60% | 9,645 psi | 55% | 686 fps | 85.8% |
| Alliant UNIQUE*² | <<locked>> | 60% | 13,619 psi | 78% | 794 fps | 92.1% |
| Baschieri & Pellagri 102 Pistol² | <<locked>> | 60% | 9,413 psi | 54% | 673 fps | 98.7% |
| Hodgdon TrailBoss*² | 1.9 gr | 60% | 4,525 psi | 26% | 476 fps | 92.1% |
| Maxam CSB 1² | <<locked>> | 60% | 13,184 psi | 76% | 755 fps | 97.4% |
| Maxam CSB 2² | <<locked>> | 60% | 12,923 psi | 74% | 781 fps | 99.9% |
| ReloadSwiss RS 14*² | 2 gr | 64% | 4,206 psi | 24% | 469 fps | 85.1% |
| ReloadSwiss RS 20*² | <<locked>> | 60% | 11,835 psi | 68% | 764 fps | 92.2% |
| SNPE Vectan A0*² | <<locked>> | 60% | 13,706 psi | 79% | 764 fps | 91.9% |
| Vihtavuori N32C Tin Star² | <<locked>> | 60% | 7,513 psi | 43% | 594 fps | 100% |
| Winchester AutoComp ² | <<locked>> | 60% | 13,213 psi | 76% | 768 fps | 96.4% |
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 .38 Spl. Wad Cut. loaded with the .357 | 148gr | H&N WC HS. ReloadSwiss RS 20 delivers the highest muzzle velocity at 850 fps; across all powders the maximum-charge window runs from 663 fps to 850 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 (120 MPa), the top charges use 54–89 %, leaving at least 11 % 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 Spl. Wad Cut. with the .357 | 148gr | H&N WC HS they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Herco, Alliant UNIQUE, SNPE Vectan A0 burn incompletely and react more sensitively to barrel length and temperature. Accurate Solo 1250, Alliant Herco, Alliant UNIQUE 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.