Load Specifications
Load data in caliber .375 SOCOM with .375 | 270gr | Swift A-Frame bullet and 4 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant AR-Comp, ReloadSwiss RS 14 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 ≥ 80% and propellant combustion ≥ 95%. 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: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Alliant AR-Comp | <<locked>> | 90% | 30,052 psi | 86% | 1791 fps | 96.7% |
| Alliant Reloder-10x | <<locked>> | 84% | 31,372 psi | 90% | 1775 fps | 96.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 31,372 psi | 90% | 1198 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 31,198 psi | 89% | 1227 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Alliant AR-Comp | 35.1 gr | 88% | 28,297 psi | 81% | 1752 fps | 95.9% |
| Alliant Reloder-10x | <<locked>> | 82% | 29,472 psi | 84% | 1736 fps | 95.4% |
| Hodgdon TrailBoss | 11.1 gr | 80% | 22,989 psi | 66% | 1066 fps | 100% |
| ReloadSwiss RS 14 | 11.3 gr | 80% | 22,771 psi | 65% | 1093 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 4 powders for .375 SOCOM loaded with the .375 | 270gr | Swift A-Frame. Alliant AR-Comp delivers the highest muzzle velocity at 1,791 fps; across all powders the maximum-charge window runs from 1,198 fps to 1,791 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 (241 MPa), the top charges use 86–90 %, leaving at least 10 % headroom. The 270.0 gr projectile in 0.375" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. 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. Alliant AR-Comp, ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for .375 SOCOM with the .375 | 270gr | Swift A-Frame they combine a high case fill with complete burn and sit in the upper velocity band. 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.