Load Specifications
Load data in caliber .38 S&W (Colt N.P.) with .358 | 148gr | Speer LBBWC bullet and 24 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 No. 2*² | <<locked>> | 64% | 15,505 psi | 89% | 771 fps | 88.3% |
| Accurate Solo 1250² | <<locked>> | 68% | 15,273 psi | 88% | 781 fps | 97.3% |
| Alliant BE-86² | <<locked>> | 68% | 15,403 psi | 89% | 787 fps | 99.1% |
| Alliant Herco* | <<locked>> | 84% | 15,229 psi | 88% | 807 fps | 91.6% |
| Alliant UNIQUE*² | <<locked>> | 68% | 14,141 psi | 81% | 784 fps | 90.3% |
| Baschieri & Pellagri 100² | <<locked>> | 64% | 15,592 psi | 90% | 761 fps | 99.7% |
| Baschieri & Pellagri 102 Pistol | <<locked>> | 84% | 15,722 psi | 90% | 791 fps | 100% |
| Hodgdon CFE Pistol² | <<locked>> | 64% | 14,823 psi | 85% | 778 fps | 96.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 8,659 psi | 50% | 614 fps | 98.8% |
| Hodgdon Universal² | <<locked>> | 64% | 15,418 psi | 89% | 794 fps | 98% |
| Lovex S020*² | <<locked>> | 64% | 15,098 psi | 87% | 794 fps | 94% |
| Maxam CSB 1² | <<locked>> | 72% | 15,447 psi | 89% | 781 fps | 97.5% |
| Maxam CSB 2² | <<locked>> | 72% | 14,823 psi | 85% | 807 fps | 99.9% |
| Maxam CSB 3² | <<locked>> | 64% | 15,069 psi | 87% | 764 fps | 99.6% |
| ReloadSwiss RS 14*ᴾ | <<locked>> | 100% | 7,600 psi | 44% | 597 fps | 93.9% |
| ReloadSwiss RS 20*² | <<locked>> | 72% | 14,750 psi | 85% | 810 fps | 93.4% |
| SNPE Vectan A0*² | <<locked>> | 68% | 14,489 psi | 83% | 755 fps | 90.2% |
| SNPE Vectan BA9 1/2² | <<locked>> | 64% | 14,808 psi | 85% | 771 fps | 96.7% |
| Somchem MP200*² | <<locked>> | 64% | 15,490 psi | 89% | 801 fps | 90.1% |
| Somchem MS200*² | <<locked>> | 64% | 14,547 psi | 84% | 768 fps | 91.9% |
| Vihtavuori N32C Tin Star | <<locked>> | 92% | 14,779 psi | 85% | 738 fps | 100% |
| Vihtavuori N330² | <<locked>> | 64% | 14,663 psi | 84% | 797 fps | 98.3% |
| Vihtavuori N340*² | <<locked>> | 68% | 15,142 psi | 87% | 791 fps | 91.8% |
| Winchester AutoComp ² | <<locked>> | 68% | 14,663 psi | 84% | 778 fps | 95.8% |
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% | 13,590 psi | 78% | 732 fps | 85.9% |
| Accurate Solo 1250*² | <<locked>> | 60% | 11,661 psi | 67% | 702 fps | 93.8% |
| Alliant BE-86² | <<locked>> | 60% | 11,385 psi | 65% | 702 fps | 96.2% |
| Alliant Herco*² | <<locked>> | 72% | 11,066 psi | 64% | 709 fps | 85.7% |
| Alliant UNIQUE*² | <<locked>> | 60% | 11,052 psi | 64% | 705 fps | 85.6% |
| Baschieri & Pellagri 100² | <<locked>> | 60% | 13,634 psi | 78% | 725 fps | 99% |
| Baschieri & Pellagri 102 Pistol*² | <<locked>> | 60% | 7,774 psi | 45% | 610 fps | 94.8% |
| Hodgdon CFE Pistol² | <<locked>> | 60% | 13,155 psi | 76% | 741 fps | 95% |
| Hodgdon TrailBoss*² | 1.6 gr | 60% | 3,756 psi | 22% | 427 fps | 85.9% |
| Hodgdon Universal² | <<locked>> | 60% | 13,590 psi | 78% | 758 fps | 96.7% |
| Lovex S020*² | <<locked>> | 60% | 13,300 psi | 76% | 755 fps | 92% |
| Maxam CSB 1*² | <<locked>> | 60% | 11,182 psi | 64% | 686 fps | 93.3% |
| Maxam CSB 2² | <<locked>> | 60% | 10,486 psi | 60% | 712 fps | 97.6% |
| Maxam CSB 3² | <<locked>> | 60% | 13,169 psi | 76% | 725 fps | 98.7% |
| ReloadSwiss RS 14* | <<locked>> | 80% | 5,265 psi | 30% | 512 fps | 87.2% |
| ReloadSwiss RS 20*² | <<locked>> | 60% | 10,341 psi | 59% | 696 fps | 86.3% |
| SNPE Vectan A0*² | <<locked>> | 60% | 11,414 psi | 66% | 682 fps | 85.7% |
| SNPE Vectan BA9 1/2² | <<locked>> | 60% | 13,068 psi | 75% | 735 fps | 95.1% |
| Somchem MP200*² | <<locked>> | 60% | 13,851 psi | 80% | 761 fps | 88% |
| Somchem MS200*² | <<locked>> | 60% | 12,908 psi | 74% | 732 fps | 89.8% |
| Vihtavuori N32C Tin Star² | 2.1 gr | 60% | 6,005 psi | 35% | 538 fps | 98.6% |
| Vihtavuori N330² | <<locked>> | 60% | 12,836 psi | 74% | 761 fps | 96.9% |
| Vihtavuori N340*² | <<locked>> | 60% | 11,835 psi | 68% | 715 fps | 87.4% |
| Winchester AutoComp *² | <<locked>> | 60% | 11,052 psi | 64% | 696 fps | 91.6% |
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 4 powders for .38 S&W (Colt N.P.) loaded with the .358 | 148gr | Speer LBBWC. Baschieri & Pellagri 102 Pistol delivers the highest muzzle velocity at 791 fps; across all powders the maximum-charge window runs from 597 fps to 791 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 4 of the 4 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (120 MPa), the top charges use 44–90 %, 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 LBBWC they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ReloadSwiss RS 14 burn incompletely and react more sensitively to barrel length and temperature. Baschieri & Pellagri 102 Pistol, Hodgdon TrailBoss, ReloadSwiss RS 14 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.