Load Specifications
Load data in caliber .38 S&W (Colt N.P.) with .358 | 148gr | Speer LHBWC bullet and 27 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.
A valid access license is required to use the Personalized Load Calculator.
You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 4"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate No. 2*² | <<locked>> | 64% | 15,519 psi | 89% | 764 fps | 87.8% |
| Accurate Solo 1250² | <<locked>> | 68% | 14,185 psi | 82% | 751 fps | 96.2% |
| Alliant BE-86² | <<locked>> | 68% | 14,518 psi | 83% | 764 fps | 98.5% |
| Alliant Herco* | <<locked>> | 84% | 14,576 psi | 84% | 787 fps | 90.5% |
| Alliant RED DOT² | <<locked>> | 64% | 15,621 psi | 90% | 748 fps | 100% |
| Alliant UNIQUE*² | <<locked>> | 68% | 14,054 psi | 81% | 774 fps | 89.8% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 15,476 psi | 89% | 751 fps | 99.6% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 84% | 14,852 psi | 85% | 771 fps | 100% |
| Baschieri & Pellagri 103 Pistol² | <<locked>> | 64% | 15,679 psi | 90% | 787 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 8,427 psi | 48% | 600 fps | 98.5% |
| Hodgdon Universal² | <<locked>> | 64% | 15,273 psi | 88% | 787 fps | 97.7% |
| Lovex S020*² | <<locked>> | 64% | 14,098 psi | 81% | 764 fps | 92.5% |
| Maxam CSB 1² | <<locked>> | 72% | 15,389 psi | 88% | 771 fps | 97.2% |
| Maxam CSB 2² | <<locked>> | 72% | 14,663 psi | 84% | 797 fps | 99.8% |
| Maxam CSB 3² | <<locked>> | 64% | 14,895 psi | 86% | 755 fps | 99.4% |
| ReloadSwiss RS 12² | <<locked>> | 64% | 15,534 psi | 89% | 807 fps | 100% |
| ReloadSwiss RS 14*ᴾ | <<locked>> | 100% | 7,397 psi | 43% | 587 fps | 93.2% |
| ReloadSwiss RS 20*² | <<locked>> | 76% | 15,708 psi | 90% | 823 fps | 94% |
| SNPE Vectan A0*² | <<locked>> | 72% | 15,360 psi | 88% | 764 fps | 90.7% |
| SNPE Vectan BA 9² | <<locked>> | 64% | 15,519 psi | 89% | 761 fps | 95.3% |
| SNPE Vectan BA9 1/2² | <<locked>> | 64% | 14,707 psi | 85% | 761 fps | 96.3% |
| Somchem MP200*² | <<locked>> | 64% | 14,678 psi | 84% | 774 fps | 88.6% |
| Somchem MS200*² | <<locked>> | 68% | 15,403 psi | 89% | 778 fps | 92.4% |
| Vihtavuori N32C Tin Star | <<locked>> | 96% | 15,650 psi | 90% | 748 fps | 100% |
| Vihtavuori N330² | <<locked>> | 68% | 15,577 psi | 90% | 810 fps | 98.6% |
| Vihtavuori N340*² | <<locked>> | 68% | 14,243 psi | 82% | 761 fps | 90.3% |
| Winchester AutoComp ² | <<locked>> | 72% | 15,592 psi | 90% | 791 fps | 96.3% |
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 No. 2*² | <<locked>> | 60% | 13,532 psi | 78% | 722 fps | 85.3% |
| Accurate Solo 1250*² | <<locked>> | 60% | 11,487 psi | 66% | 692 fps | 93.2% |
| Alliant BE-86² | <<locked>> | 60% | 11,269 psi | 65% | 696 fps | 95.8% |
| Alliant Herco*² | <<locked>> | 72% | 11,023 psi | 63% | 699 fps | 85.2% |
| Alliant RED DOT² | <<locked>> | 60% | 13,373 psi | 77% | 709 fps | 100% |
| Alliant UNIQUE*² | <<locked>> | 64% | 12,415 psi | 71% | 735 fps | 87.5% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 13,431 psi | 77% | 712 fps | 98.7% |
| Baschieri & Pellagri 102 Pistol*² | <<locked>> | 60% | 7,092 psi | 41% | 581 fps | 93.1% |
| Baschieri & Pellagri 103 Pistol² | <<locked>> | 60% | 13,314 psi | 77% | 741 fps | 99.3% |
| Hodgdon TrailBoss*² | 1.6 gr | 64% | 3,887 psi | 22% | 433 fps | 86.2% |
| Hodgdon Universal² | <<locked>> | 60% | 13,402 psi | 77% | 748 fps | 96.3% |
| Lovex S020*² | <<locked>> | 60% | 12,343 psi | 71% | 725 fps | 90.4% |
| Maxam CSB 1*² | <<locked>> | 60% | 11,008 psi | 63% | 676 fps | 92.6% |
| Maxam CSB 2² | <<locked>> | 60% | 9,456 psi | 54% | 679 fps | 96.1% |
| Maxam CSB 3² | <<locked>> | 60% | 12,923 psi | 74% | 715 fps | 98.4% |
| ReloadSwiss RS 12² | <<locked>> | 60% | 13,489 psi | 78% | 768 fps | 100% |
| ReloadSwiss RS 14* | <<locked>> | 80% | 5,047 psi | 29% | 499 fps | 86% |
| ReloadSwiss RS 20*² | <<locked>> | 64% | 10,921 psi | 63% | 705 fps | 87% |
| SNPE Vectan A0*² | <<locked>> | 60% | 11,327 psi | 65% | 673 fps | 85.1% |
| SNPE Vectan BA 9*² | <<locked>> | 60% | 13,750 psi | 79% | 725 fps | 93.6% |
| SNPE Vectan BA9 1/2*² | <<locked>> | 60% | 12,923 psi | 74% | 722 fps | 94.6% |
| Somchem MP200*² | <<locked>> | 60% | 13,053 psi | 75% | 735 fps | 86.4% |
| Somchem MS200*² | <<locked>> | 60% | 12,009 psi | 69% | 702 fps | 88% |
| Vihtavuori N32C Tin Star² | 2 gr | 60% | 5,700 psi | 33% | 525 fps | 98% |
| Vihtavuori N330² | <<locked>> | 60% | 11,850 psi | 68% | 732 fps | 95.6% |
| Vihtavuori N340*² | <<locked>> | 60% | 10,979 psi | 63% | 686 fps | 85.5% |
| Winchester AutoComp *² | <<locked>> | 60% | 10,950 psi | 63% | 686 fps | 91% |
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 27 powders for .38 S&W (Colt N.P.) loaded with the .358 | 148gr | Speer LHBWC. ReloadSwiss RS 20 delivers the highest muzzle velocity at 823 fps; across all powders the maximum-charge window runs from 587 fps to 823 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 5 of the 27 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (120 MPa), the top charges use 43–90 %, 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 S&W (Colt N.P.) with the .358 | 148gr | Speer LHBWC they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate No. 2, Alliant Herco, Alliant UNIQUE burn incompletely and react more sensitively to barrel length and temperature. Accurate No. 2, Accurate Solo 1250, 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.