Load Specifications
Load data in caliber .378 Weath. Mag. with .375 | 300gr | Barnes X S bullet and 79 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Accurate MAGPRO, Accurate High Country and Alliant Reloder-26.
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: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 96% | 57,740 psi | 90% | 2756 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 55,811 psi | 87% | 2736 fps | 100% |
| Accurate High Country | <<locked>> | 92% | 54,708 psi | 86% | 2844 fps | 99% |
| Accurate MAGPRO | <<locked>> | 94% | 55,448 psi | 87% | 2848 fps | 98.2% |
| ADI AR 2208 | <<locked>> | 82% | 56,376 psi | 88% | 2684 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 55,521 psi | 87% | 2782 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 96% | 56,623 psi | 89% | 2838 fps | 99.1% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 47,906 psi | 75% | 2690 fps | 97.9% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 43,062 psi | 67% | 2667 fps | 99.4% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 55,796 psi | 87% | 2782 fps | 99.6% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 55,796 psi | 87% | 2782 fps | 99.6% |
| Alliant Reloder-16 | <<locked>> | 88% | 55,666 psi | 87% | 2782 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 56,956 psi | 89% | 2799 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 55,114 psi | 86% | 2772 fps | 99.5% |
| Alliant Reloder-22 | <<locked>> | 96% | 56,681 psi | 89% | 2838 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 96% | 54,288 psi | 85% | 2762 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 53,388 psi | 84% | 2818 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 92% | 54,302 psi | 85% | 2851 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 96% | 55,158 psi | 86% | 2746 fps | 96.2% |
| Bofors RP15 | <<locked>> | 98% | 55,680 psi | 87% | 2825 fps | 99.6% |
| Bofors RP30ᴾ | <<locked>> | 100% | 49,632 psi | 78% | 2766 fps | 98.6% |
| Bofors RP5 | <<locked>> | 96% | 56,681 psi | 89% | 2838 fps | 99.7% |
| Bofors RP7 | <<locked>> | 84% | 54,563 psi | 86% | 2680 fps | 99.8% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 52,475 psi | 82% | 2769 fps | 99.1% |
| Hodgdon H414 | <<locked>> | 86% | 56,811 psi | 89% | 2782 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 55,956 psi | 88% | 2740 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 94% | 56,782 psi | 89% | 2779 fps | 98.6% |
| Hodgdon H4831 SC | <<locked>> | 94% | 55,767 psi | 87% | 2766 fps | 98.4% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 56,159 psi | 88% | 2703 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 52,417 psi | 82% | 2884 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 86% | 56,739 psi | 89% | 2818 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,347 psi | 59% | 1683 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 55,535 psi | 87% | 2717 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 84% | 55,564 psi | 87% | 2697 fps | 99.9% |
| IMR 4831 | <<locked>> | 88% | 55,753 psi | 87% | 2723 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 54,723 psi | 86% | 2713 fps | 98.4% |
| IMR 7828 SSC | <<locked>> | 96% | 54,621 psi | 86% | 2822 fps | 98.9% |
| Lovex S065 | <<locked>> | 86% | 56,579 psi | 89% | 2700 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 54,824 psi | 86% | 2700 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 55,259 psi | 87% | 2723 fps | 100% |
| Norma 204 | <<locked>> | 88% | 56,391 psi | 88% | 2769 fps | 99.5% |
| Norma 217ᴾ | <<locked>> | 100% | 38,986 psi | 61% | 2608 fps | 98.1% |
| Norma MRP | <<locked>> | 94% | 56,623 psi | 89% | 2864 fps | 100% |
| Norma URP | <<locked>> | 88% | 57,188 psi | 90% | 2762 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 55,158 psi | 86% | 2838 fps | 99.2% |
| Ramshot Hunter | <<locked>> | 88% | 55,883 psi | 88% | 2772 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 57,261 psi | 90% | 2831 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,232 psi | 60% | 1722 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 56,217 psi | 88% | 2782 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 55,303 psi | 87% | 2759 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 56,550 psi | 89% | 2831 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 52,779 psi | 83% | 2881 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 47,964 psi | 75% | 2772 fps | 97% |
| Rottweil R 903 | <<locked>> | 82% | 56,159 psi | 88% | 2684 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 56,869 psi | 89% | 2749 fps | 99% |
| Rottweil R 905 | <<locked>> | 92% | 54,737 psi | 86% | 2762 fps | 99.6% |
| Rottweil R 907 | <<locked>> | 84% | 54,563 psi | 86% | 2680 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 86% | 56,579 psi | 89% | 2700 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 54,824 psi | 86% | 2700 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 56,927 psi | 89% | 2733 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 55,579 psi | 87% | 2552 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 55,869 psi | 88% | 2657 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 54,288 psi | 85% | 2759 fps | 99.5% |
| Somchem S355 | <<locked>> | 82% | 55,782 psi | 87% | 2677 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 55,056 psi | 86% | 2694 fps | 98.2% |
| Somchem S365 | <<locked>> | 90% | 57,377 psi | 90% | 2766 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 55,463 psi | 87% | 2740 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 84% | 56,623 psi | 89% | 2644 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 55,521 psi | 87% | 2707 fps | 100% |
| Vihtavuori N165 | <<locked>> | 96% | 54,607 psi | 86% | 2717 fps | 99.7% |
| Vihtavuori N550 | <<locked>> | 86% | 54,868 psi | 86% | 2717 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 57,305 psi | 90% | 2792 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 56,405 psi | 88% | 2858 fps | 98.8% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 56,376 psi | 88% | 2841 fps | 98.9% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 49,240 psi | 77% | 2779 fps | 96.7% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 54,592 psi | 86% | 2667 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 56,956 psi | 89% | 2785 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 98% | 54,636 psi | 86% | 2894 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 54,998 psi | 86% | 2733 fps | 99.5% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 35,201 psi | 55% | 2372 fps | 98.1% |
| Accurate 4350 | <<locked>> | 80% | 46,166 psi | 72% | 2592 fps | 100% |
| Accurate High Country | 88.6 gr | 80% | 37,072 psi | 58% | 2513 fps | 95% |
| Accurate MAGPRO | 97.1 gr | 86% | 42,685 psi | 67% | 2625 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 53,243 psi | 83% | 2641 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 38,290 psi | 60% | 2470 fps | 96.3% |
| ADI AR 2213 | <<locked>> | 84% | 38,986 psi | 61% | 2513 fps | 95.1% |
| ADI AR 2217 | <<locked>> | 94% | 39,842 psi | 62% | 2530 fps | 95.6% |
| ADI AR 2225 | <<locked>> | 90% | 32,155 psi | 50% | 2402 fps | 96% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 38,609 psi | 61% | 2474 fps | 96.5% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 38,609 psi | 61% | 2474 fps | 96.5% |
| Alliant Reloder-16 | <<locked>> | 80% | 43,497 psi | 68% | 2589 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 49,821 psi | 78% | 2697 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 38,276 psi | 60% | 2467 fps | 96.5% |
| Alliant Reloder-22 | <<locked>> | 80% | 34,461 psi | 54% | 2421 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 80% | 33,330 psi | 52% | 2395 fps | 99.9% |
| Alliant Reloder-25 | <<locked>> | 80% | 29,428 psi | 46% | 2316 fps | 96.7% |
| Alliant Reloder-26 | 91.3 gr | 80% | 36,013 psi | 56% | 2526 fps | 99.4% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 51,967 psi | 81% | 2694 fps | 95.4% |
| Bofors RP15 | <<locked>> | 82% | 34,330 psi | 54% | 2418 fps | 95% |
| Bofors RP30 | <<locked>> | 90% | 36,506 psi | 57% | 2503 fps | 95.2% |
| Bofors RP5 | <<locked>> | 80% | 34,461 psi | 54% | 2421 fps | 95.3% |
| Bofors RP7 | <<locked>> | 80% | 48,573 psi | 76% | 2585 fps | 99.3% |
| Hodgdon H1000 | <<locked>> | 90% | 38,319 psi | 60% | 2497 fps | 95.8% |
| Hodgdon H414 | <<locked>> | 80% | 47,152 psi | 74% | 2631 fps | 99.5% |
| Hodgdon H4350 | <<locked>> | 80% | 49,516 psi | 78% | 2638 fps | 99% |
| Hodgdon H4831 | <<locked>> | 84% | 41,336 psi | 65% | 2516 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 84% | 40,741 psi | 64% | 2503 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 41,481 psi | 65% | 2484 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 86% | 34,301 psi | 54% | 2490 fps | 95.6% |
| Hodgdon Superformance | <<locked>> | 80% | 46,224 psi | 72% | 2654 fps | 99.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,036 psi | 44% | 1503 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 43,859 psi | 69% | 2523 fps | 98.7% |
| IMR 4451 Enduron | <<locked>> | 80% | 49,429 psi | 77% | 2602 fps | 99.6% |
| IMR 4831 | <<locked>> | 80% | 43,830 psi | 69% | 2539 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 82% | 40,669 psi | 64% | 2464 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 86% | 39,958 psi | 63% | 2549 fps | 95.6% |
| Lovex S065 | <<locked>> | 80% | 47,645 psi | 75% | 2562 fps | 99.9% |
| Lovex S070 | <<locked>> | 80% | 45,977 psi | 72% | 2556 fps | 99.4% |
| Lovex S071 | <<locked>> | 80% | 30,864 psi | 48% | 2267 fps | 96.7% |
| Norma 204 | <<locked>> | 80% | 43,642 psi | 68% | 2556 fps | 97.7% |
| Norma 217 | <<locked>> | 94% | 32,634 psi | 51% | 2451 fps | 95.8% |
| Norma MRP | <<locked>> | 80% | 35,795 psi | 56% | 2487 fps | 97.3% |
| Norma URP | <<locked>> | 80% | 44,846 psi | 70% | 2572 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 39,639 psi | 62% | 2556 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 43,511 psi | 68% | 2572 fps | 99.5% |
| Ramshot Magnum | <<locked>> | 84% | 33,417 psi | 52% | 2395 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,776 psi | 45% | 1539 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 52,620 psi | 82% | 2733 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 45,556 psi | 71% | 2608 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 43,468 psi | 68% | 2621 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 84% | 31,430 psi | 49% | 2411 fps | 95.4% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 41,901 psi | 66% | 2657 fps | 95.2% |
| Rottweil R 903 | <<locked>> | 80% | 52,881 psi | 83% | 2638 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 39,668 psi | 62% | 2448 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 80% | 37,811 psi | 59% | 2457 fps | 96.5% |
| Rottweil R 907 | <<locked>> | 80% | 48,573 psi | 76% | 2585 fps | 99.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 47,645 psi | 75% | 2562 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 80% | 45,977 psi | 72% | 2556 fps | 99.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 53,476 psi | 84% | 2687 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 52,460 psi | 82% | 2510 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 46,586 psi | 73% | 2513 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 37,478 psi | 59% | 2454 fps | 96.4% |
| Somchem S355 | <<locked>> | 80% | 52,533 psi | 82% | 2631 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 42,844 psi | 67% | 2490 fps | 95.6% |
| Somchem S365 | <<locked>> | 80% | 41,916 psi | 66% | 2539 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 38,638 psi | 61% | 2448 fps | 97.5% |
| Vihtavuori N150 | <<locked>> | 80% | 50,212 psi | 79% | 2559 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 46,151 psi | 72% | 2566 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 33,446 psi | 52% | 2326 fps | 95.4% |
| Vihtavuori N550 | <<locked>> | 80% | 45,730 psi | 72% | 2572 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 37,507 psi | 59% | 2467 fps | 99.8% |
| Vihtavuori N560 | <<locked>> | 84% | 40,944 psi | 64% | 2582 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 88% | 38,595 psi | 60% | 2523 fps | 95% |
| Vihtavuori N568 | <<locked>> | 98% | 46,050 psi | 72% | 2720 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 44,860 psi | 70% | 2526 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 47,297 psi | 74% | 2631 fps | 99.5% |
| Winchester StaBALL HD | <<locked>> | 80% | 29,936 psi | 47% | 2425 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 35,114 psi | 55% | 2372 fps | 95.3% |
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 79 powders for .378 Weath. Mag. loaded with the .375 | 300gr | Barnes X S. Winchester StaBALL HD delivers the highest muzzle velocity at 2,894 fps; across all powders the maximum-charge window runs from 1,683 fps to 2,894 fps. ADI AR 2217 gives the best case fill at 100 %, and 79 of the 79 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 59–90 %, leaving at least 10 % headroom. The 300.0 gr projectile in 0.375" calls for a 1:16.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-25 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. Accurate MAGPRO, Accurate High Country, Alliant Reloder-26 rank at the top here: for .378 Weath. Mag. with the .375 | 300gr | Barnes X S they combine a high case fill with complete burn and sit in the upper velocity band. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.