Load Specifications
Load data in caliber .38 S&W (Colt N.P.) with .357 | 127gr | H&N KS HP HS bullet and 29 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Baschieri & Pellagri 102 Pistol and Vihtavuori N32C Tin Star.
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>> | 72% | 15,389 psi | 88% | 850 fps | 95.3% |
| ADI AS 30² | <<locked>> | 64% | 15,548 psi | 89% | 810 fps | 100% |
| Alliant BE-86² | <<locked>> | 72% | 15,229 psi | 88% | 856 fps | 97.5% |
| Alliant Herco* | <<locked>> | 88% | 14,881 psi | 86% | 866 fps | 88.1% |
| Alliant RED DOT² | <<locked>> | 68% | 15,418 psi | 89% | 823 fps | 100% |
| Alliant UNIQUE*² | <<locked>> | 76% | 15,664 psi | 90% | 886 fps | 89% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 13,953 psi | 80% | 797 fps | 97.7% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 88% | 14,533 psi | 84% | 843 fps | 99.5% |
| Baschieri & Pellagri 103 Pistol² | <<locked>> | 64% | 13,619 psi | 78% | 823 fps | 98.3% |
| Hodgdon Clays² | <<locked>> | 64% | 14,779 psi | 85% | 755 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 7,556 psi | 43% | 636 fps | 95.6% |
| Hodgdon Universal² | <<locked>> | 68% | 15,374 psi | 88% | 866 fps | 96.1% |
| Lovex S020*² | <<locked>> | 68% | 14,997 psi | 86% | 860 fps | 91% |
| Maxam CSB 1² | <<locked>> | 76% | 15,490 psi | 89% | 850 fps | 95.5% |
| Maxam CSB 2² | <<locked>> | 76% | 14,417 psi | 83% | 876 fps | 99% |
| Maxam CSB 3² | <<locked>> | 68% | 15,331 psi | 88% | 840 fps | 98.6% |
| Maxam CSB 4² | <<locked>> | 64% | 14,504 psi | 83% | 814 fps | 99.5% |
| ReloadSwiss RS 12² | <<locked>> | 68% | 15,316 psi | 88% | 889 fps | 100% |
| ReloadSwiss RS 14*ᴾ | <<locked>> | 100% | 6,556 psi | 38% | 614 fps | 88.4% |
| ReloadSwiss RS 20*² | <<locked>> | 76% | 14,562 psi | 84% | 873 fps | 89.9% |
| SNPE Vectan A1² | <<locked>> | 64% | 15,519 psi | 89% | 837 fps | 96.8% |
| SNPE Vectan BA 9*² | <<locked>> | 64% | 14,823 psi | 85% | 820 fps | 92.4% |
| SNPE Vectan BA9 1/2*² | <<locked>> | 68% | 14,895 psi | 86% | 840 fps | 94.5% |
| Somchem MS200*² | <<locked>> | 68% | 14,605 psi | 84% | 833 fps | 88.9% |
| Vihtavuori N320² | <<locked>> | 64% | 14,344 psi | 82% | 833 fps | 99.6% |
| Vihtavuori N32C Tin Starᴾ | <<locked>> | 100% | 15,534 psi | 89% | 827 fps | 100% |
| Vihtavuori N330² | <<locked>> | 68% | 14,518 psi | 83% | 866 fps | 96.3% |
| Vihtavuori N340*² | <<locked>> | 72% | 15,040 psi | 86% | 853 fps | 88.5% |
| Winchester AutoComp *² | <<locked>> | 72% | 13,706 psi | 79% | 823 fps | 92.3% |
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 1250*² | <<locked>> | 60% | 10,356 psi | 60% | 725 fps | 88.8% |
| ADI AS 30² | <<locked>> | 60% | 13,445 psi | 77% | 768 fps | 100% |
| Alliant BE-86*² | <<locked>> | 60% | 10,022 psi | 58% | 728 fps | 91.7% |
| Alliant Herco* | <<locked>> | 84% | 13,445 psi | 77% | 833 fps | 86.2% |
| Alliant RED DOT² | <<locked>> | 60% | 12,328 psi | 71% | 758 fps | 99.9% |
| Alliant UNIQUE*² | <<locked>> | 72% | 13,996 psi | 80% | 846 fps | 86.9% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 12,183 psi | 70% | 755 fps | 96.2% |
| Baschieri & Pellagri 102 Pistol*² | 2.7 gr | 60% | 6,382 psi | 37% | 607 fps | 88.1% |
| Baschieri & Pellagri 103 Pistol² | <<locked>> | 60% | 12,270 psi | 71% | 791 fps | 97.3% |
| Hodgdon Clays² | <<locked>> | 60% | 12,720 psi | 73% | 715 fps | 100% |
| Hodgdon TrailBoss*² | <<locked>> | 72% | 4,322 psi | 25% | 499 fps | 85.4% |
| Hodgdon Universal*² | <<locked>> | 60% | 11,995 psi | 69% | 784 fps | 92.5% |
| Lovex S020*² | <<locked>> | 60% | 11,618 psi | 67% | 778 fps | 86.5% |
| Maxam CSB 1*² | <<locked>> | 60% | 9,935 psi | 57% | 709 fps | 88.2% |
| Maxam CSB 2*² | <<locked>> | 60% | 8,238 psi | 47% | 709 fps | 91.6% |
| Maxam CSB 3² | <<locked>> | 60% | 11,748 psi | 68% | 758 fps | 95.7% |
| Maxam CSB 4² | <<locked>> | 60% | 12,604 psi | 72% | 771 fps | 98.6% |
| ReloadSwiss RS 12² | <<locked>> | 60% | 11,705 psi | 67% | 807 fps | 98.8% |
| ReloadSwiss RS 14* | <<locked>> | 92% | 5,700 psi | 33% | 577 fps | 85.5% |
| ReloadSwiss RS 20*² | <<locked>> | 68% | 11,647 psi | 67% | 791 fps | 85.1% |
| SNPE Vectan A1*² | <<locked>> | 60% | 13,039 psi | 75% | 781 fps | 94.6% |
| SNPE Vectan BA 9*² | <<locked>> | 60% | 12,473 psi | 72% | 764 fps | 89.5% |
| SNPE Vectan BA9 1/2*² | <<locked>> | 60% | 11,647 psi | 67% | 761 fps | 90.6% |
| Somchem MS200*² | <<locked>> | 64% | 13,039 psi | 75% | 797 fps | 86.8% |
| Vihtavuori N320² | <<locked>> | 60% | 12,415 psi | 71% | 791 fps | 98.8% |
| Vihtavuori N32C Tin Star*² | 2.1 gr | 60% | 5,163 psi | 30% | 554 fps | 94.7% |
| Vihtavuori N330*² | <<locked>> | 60% | 10,501 psi | 60% | 761 fps | 91.1% |
| Vihtavuori N340*² | <<locked>> | 68% | 13,358 psi | 77% | 814 fps | 86.3% |
| Winchester AutoComp *² | <<locked>> | 60% | 9,747 psi | 56% | 719 fps | 86.1% |
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 29 powders for .38 S&W (Colt N.P.) loaded with the .357 | 127gr | H&N KS HP HS. ReloadSwiss RS 12 delivers the highest muzzle velocity at 889 fps; across all powders the maximum-charge window runs from 614 fps to 889 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 5 of the 29 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (120 MPa), the top charges use 38–90 %, leaving at least 10 % headroom. Hodgdon TrailBoss, ReloadSwiss RS 14, Vihtavuori N32C Tin Star 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. Baschieri & Pellagri 102 Pistol, Vihtavuori N32C Tin Star rank at the top here: for .38 S&W (Colt N.P.) with the .357 | 127gr | H&N KS HP HS they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Herco, Alliant UNIQUE, Lovex S020 burn incompletely and react more sensitively to barrel length and temperature. Accurate Solo 1250, ADI AS 30, Alliant BE-86 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.