Load Specifications
Load data in caliber .375 Win. with .375 | 285gr | Speer Grand Slam bullet and 22 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Shooters World Buffalo Rifle, Lovex D060 and Shooters World Blackout.
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.
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: 22"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 1680ᴾ | <<locked>> | 100% | 43,990 psi | 80% | 1772 fps | 97.6% |
| Accurate 5744 | <<locked>> | 86% | 47,007 psi | 85% | 1804 fps | 98.9% |
| Accurate No. 11 FS | <<locked>> | 90% | 47,036 psi | 85% | 1791 fps | 100% |
| ADI AR 2205 | <<locked>> | 94% | 49,661 psi | 90% | 1749 fps | 100% |
| ADI AR 2207ᴾ | <<locked>> | 100% | 33,779 psi | 61% | 1729 fps | 99.2% |
| Alliant Reloder-7ᴾ | <<locked>> | 100% | 35,853 psi | 65% | 1719 fps | 96.9% |
| Hodgdon LilGun | <<locked>> | 88% | 49,661 psi | 90% | 1837 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 24,642 psi | 45% | 1024 fps | 100% |
| IMR 4198ᴾ | <<locked>> | 100% | 32,010 psi | 58% | 1644 fps | 95.7% |
| IMR 4227ᴾ | <<locked>> | 100% | 46,847 psi | 85% | 1791 fps | 99.7% |
| Lovex D060 | <<locked>> | 92% | 47,007 psi | 85% | 1804 fps | 98.9% |
| Lovex D063 | <<locked>> | 90% | 49,647 psi | 90% | 1824 fps | 99.3% |
| Lovex S040 | <<locked>> | 86% | 48,718 psi | 88% | 1722 fps | 100% |
| Lovex S053ᴾ | <<locked>> | 100% | 42,931 psi | 78% | 1759 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 22,945 psi | 42% | 1043 fps | 100% |
| ReloadSwiss RS 36ᴾ | <<locked>> | 100% | 44,541 psi | 81% | 1811 fps | 99.6% |
| Shooters World Blackout | <<locked>> | 90% | 49,647 psi | 90% | 1824 fps | 99.3% |
| Shooters World Buffalo Rifle | <<locked>> | 92% | 47,007 psi | 85% | 1804 fps | 98.9% |
| Shooters World SOCOM | <<locked>> | 92% | 46,717 psi | 85% | 1785 fps | 99.3% |
| SNPE Vectan BA6 1/2ᴾ | <<locked>> | 100% | 39,755 psi | 72% | 1631 fps | 100% |
| Vihtavuori N110 | <<locked>> | 98% | 48,762 psi | 88% | 1762 fps | 100% |
| Vihtavuori N120ᴾ | <<locked>> | 100% | 34,519 psi | 63% | 1709 fps | 99.8% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 22"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 1680 | <<locked>> | 94% | 35,070 psi | 64% | 1667 fps | 95.7% |
| Accurate 5744 | <<locked>> | 80% | 38,435 psi | 70% | 1699 fps | 97.5% |
| Accurate No. 11 FS | <<locked>> | 80% | 32,924 psi | 60% | 1627 fps | 99% |
| ADI AR 2205 | <<locked>> | 80% | 31,038 psi | 56% | 1542 fps | 99.6% |
| ADI AR 2207 | <<locked>> | 88% | 22,292 psi | 40% | 1529 fps | 95.7% |
| Alliant Reloder-7 | <<locked>> | 96% | 31,285 psi | 57% | 1657 fps | 95.6% |
| Hodgdon LilGun | <<locked>> | 80% | 36,521 psi | 66% | 1713 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 16,868 psi | 31% | 906 fps | 100% |
| IMR 4198 | <<locked>> | 98% | 30,400 psi | 55% | 1621 fps | 95.1% |
| IMR 4227 | <<locked>> | 82% | 25,744 psi | 47% | 1509 fps | 95.5% |
| Lovex D060 | 20 gr | 80% | 32,039 psi | 58% | 1608 fps | 95.8% |
| Lovex D063 | <<locked>> | 80% | 34,432 psi | 62% | 1647 fps | 96.7% |
| Lovex S040 | <<locked>> | 80% | 39,755 psi | 72% | 1634 fps | 100% |
| Lovex S053 | <<locked>> | 80% | 22,510 psi | 41% | 1467 fps | 97.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 15,200 psi | 28% | 919 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 84% | 25,440 psi | 46% | 1545 fps | 95.3% |
| Shooters World Blackout | 22.3 gr | 80% | 34,432 psi | 62% | 1647 fps | 96.7% |
| Shooters World Buffalo Rifle | 20 gr | 80% | 32,039 psi | 58% | 1608 fps | 95.8% |
| Shooters World SOCOM | <<locked>> | 80% | 30,342 psi | 55% | 1581 fps | 96.1% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 21,466 psi | 39% | 1388 fps | 100% |
| Vihtavuori N110 | <<locked>> | 80% | 26,890 psi | 49% | 1519 fps | 100% |
| Vihtavuori N120 | <<locked>> | 84% | 20,001 psi | 36% | 1453 fps | 95.6% |
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 22 powders for .375 Win. loaded with the .375 | 285gr | Speer Grand Slam. Hodgdon LilGun delivers the highest muzzle velocity at 1,837 fps; across all powders the maximum-charge window runs from 1,024 fps to 1,837 fps. Accurate 1680 gives the best case fill at 100 %, and 22 of the 22 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (380 MPa), the top charges use 42–90 %, leaving at least 10 % headroom. The 285.0 gr projectile in 0.375" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 1680, ADI AR 2207, Alliant Reloder-7 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. Shooters World Buffalo Rifle, Lovex D060, Shooters World Blackout rank at the top here: for .375 Win. with the .375 | 285gr | Speer Grand Slam 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.