Load Specifications
Load data in caliber .38 Long Colt with .355 | 90gr | Hornady XTP bullet and 4 powders. The key underlying parameters are shown in the table above.
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 |
|---|---|---|---|---|---|---|
| Baschieri & Pellagri 102 Pistol*² | <<locked>> | 64% | 10,617 psi | 81% | 928 fps | 94.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 11,037 psi | 85% | 912 fps | 98.3% |
| ReloadSwiss RS 14*ᴾ | <<locked>> | 100% | 9,950 psi | 76% | 889 fps | 93.1% |
| Vihtavuori N32C Tin Star² | <<locked>> | 72% | 11,211 psi | 86% | 925 fps | 100% |
Start Load - Barrel Length: 4"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Baschieri & Pellagri 102 Pistol*² | <<locked>> | 60% | 9,471 psi | 73% | 886 fps | 92.9% |
| Hodgdon TrailBoss*² | <<locked>> | 60% | 5,308 psi | 41% | 653 fps | 87.1% |
| ReloadSwiss RS 14*² | <<locked>> | 76% | 6,512 psi | 50% | 732 fps | 85.2% |
| Vihtavuori N32C Tin Star² | <<locked>> | 60% | 8,267 psi | 63% | 817 fps | 98.6% |
* 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 Long Colt loaded with the .355 | 90gr | Hornady XTP. Baschieri & Pellagri 102 Pistol delivers the highest muzzle velocity at 928 fps; across all powders the maximum-charge window runs from 889 fps to 928 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 2 of the 4 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (90 MPa), the top charges use 76–86 %, leaving at least 14 % 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. As outliers, Baschieri & Pellagri 102 Pistol, 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.