Load Specifications
Load data in caliber .378 Weath. Mag. with .375 | 300gr | Nosler Solid bullet and 87 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Vihtavuori N560 and Norma MRP.
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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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 84% | 56,028 psi | 88% | 2677 fps | 99.8% |
| Accurate 3100 | <<locked>> | 96% | 54,085 psi | 85% | 2730 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 55,869 psi | 88% | 2762 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 57,000 psi | 89% | 2884 fps | 98% |
| ADI AR 2208 | <<locked>> | 84% | 57,609 psi | 90% | 2720 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 56,594 psi | 89% | 2818 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 96% | 54,288 psi | 85% | 2822 fps | 98.8% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 45,339 psi | 71% | 2664 fps | 97.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 40,147 psi | 63% | 2628 fps | 99% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 55,274 psi | 87% | 2694 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 56,811 psi | 89% | 2815 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 54,230 psi | 85% | 2779 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 56,115 psi | 88% | 2805 fps | 99.6% |
| Alliant Reloder-22 | <<locked>> | 98% | 57,537 psi | 90% | 2871 fps | 99.8% |
| Alliant Reloder-23 | <<locked>> | 98% | 54,853 psi | 86% | 2789 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 50,647 psi | 79% | 2795 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 55,085 psi | 86% | 2881 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 56,405 psi | 88% | 2782 fps | 96.6% |
| Bofors RP15ᴾ | <<locked>> | 100% | 56,478 psi | 89% | 2854 fps | 99.7% |
| Bofors RP3 | <<locked>> | 82% | 56,217 psi | 88% | 2710 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 46,441 psi | 73% | 2730 fps | 98.2% |
| Bofors RP5 | <<locked>> | 98% | 57,537 psi | 90% | 2871 fps | 99.8% |
| Bofors RP7 | <<locked>> | 86% | 55,361 psi | 87% | 2713 fps | 99.9% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 46,572 psi | 73% | 2690 fps | 98.3% |
| Hodgdon H380 | <<locked>> | 82% | 56,391 psi | 88% | 2733 fps | 100% |
| Hodgdon H414 | <<locked>> | 84% | 55,100 psi | 86% | 2779 fps | 100% |
| Hodgdon H4350 | <<locked>> | 88% | 55,608 psi | 87% | 2753 fps | 99.7% |
| Hodgdon H4831ᴾ | <<locked>> | 100% | 57,159 psi | 90% | 2802 fps | 98.7% |
| Hodgdon H4831 SC | <<locked>> | 96% | 57,014 psi | 89% | 2802 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 57,029 psi | 89% | 2736 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 49,501 psi | 78% | 2851 fps | 99.7% |
| Hodgdon Superformance | <<locked>> | 86% | 54,114 psi | 85% | 2799 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,854 psi | 58% | 1686 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 57,116 psi | 90% | 2707 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 56,565 psi | 89% | 2697 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 55,158 psi | 86% | 2684 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 56,681 psi | 89% | 2749 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 86% | 56,840 psi | 89% | 2736 fps | 100% |
| IMR 4831 | <<locked>> | 94% | 57,334 psi | 90% | 2766 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 55,579 psi | 87% | 2746 fps | 98.6% |
| IMR 7828 SSC | <<locked>> | 96% | 55,869 psi | 88% | 2858 fps | 99.1% |
| Lovex S062 | <<locked>> | 82% | 57,479 psi | 90% | 2694 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 57,276 psi | 90% | 2730 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 55,303 psi | 87% | 2726 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 51,605 psi | 81% | 2694 fps | 100% |
| Norma 204 | <<locked>> | 90% | 57,493 psi | 90% | 2805 fps | 99.6% |
| Norma 217ᴾ | <<locked>> | 100% | 35,679 psi | 56% | 2552 fps | 97.2% |
| Norma MRP | <<locked>> | 96% | 57,377 psi | 90% | 2894 fps | 100% |
| Norma URP | <<locked>> | 88% | 54,433 psi | 85% | 2746 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 55,825 psi | 87% | 2867 fps | 99.4% |
| Ramshot Hunter | <<locked>> | 90% | 56,724 psi | 89% | 2805 fps | 100% |
| Ramshot Magnum | <<locked>> | 98% | 56,608 psi | 89% | 2841 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,637 psi | 59% | 1726 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 56,043 psi | 88% | 2720 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 57,667 psi | 90% | 2818 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 55,883 psi | 88% | 2789 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 54,012 psi | 85% | 2815 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 49,719 psi | 78% | 2848 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 44,788 psi | 70% | 2736 fps | 96.2% |
| Rottweil R 903 | <<locked>> | 84% | 56,565 psi | 89% | 2710 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 54,447 psi | 85% | 2733 fps | 98.8% |
| Rottweil R 905 | <<locked>> | 94% | 55,506 psi | 87% | 2795 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 86% | 55,361 psi | 87% | 2713 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 88% | 57,276 psi | 90% | 2730 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 57,479 psi | 90% | 2694 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 55,303 psi | 87% | 2726 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 54,389 psi | 85% | 2720 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 56,681 psi | 89% | 2582 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 56,608 psi | 89% | 2687 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 55,042 psi | 86% | 2792 fps | 99.6% |
| Somchem S355 | <<locked>> | 84% | 56,260 psi | 88% | 2703 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 56,057 psi | 88% | 2730 fps | 98.4% |
| Somchem S365 | <<locked>> | 90% | 54,505 psi | 85% | 2749 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 56,086 psi | 88% | 2769 fps | 99.9% |
| Unknown powder | <<locked>> | 86% | 54,853 psi | 86% | 2749 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 57,493 psi | 90% | 2677 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 56,318 psi | 88% | 2736 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 55,419 psi | 87% | 2749 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 88% | 55,477 psi | 87% | 2746 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 57,305 psi | 90% | 2812 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 57,363 psi | 90% | 2890 fps | 99% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 53,026 psi | 83% | 2812 fps | 98.6% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 46,166 psi | 72% | 2743 fps | 96% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 55,724 psi | 87% | 2700 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 55,100 psi | 86% | 2779 fps | 100% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 55,506 psi | 87% | 2920 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 53,780 psi | 84% | 2733 fps | 99.4% |
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 2700 | <<locked>> | 80% | 49,182 psi | 77% | 2575 fps | 99.3% |
| Accurate 3100 | <<locked>> | 80% | 31,633 psi | 50% | 2316 fps | 97% |
| Accurate 4350 | <<locked>> | 80% | 42,670 psi | 67% | 2556 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 46,267 psi | 73% | 2703 fps | 95.7% |
| ADI AR 2208 | <<locked>> | 80% | 50,966 psi | 80% | 2625 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 35,853 psi | 56% | 2438 fps | 95.6% |
| ADI AR 2213 | <<locked>> | 86% | 38,914 psi | 61% | 2533 fps | 95.1% |
| ADI AR 2217 | <<locked>> | 96% | 39,711 psi | 62% | 2549 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 92% | 31,227 psi | 49% | 2402 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 51,967 psi | 81% | 2648 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 41,075 psi | 64% | 2562 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 47,021 psi | 74% | 2674 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 35,723 psi | 56% | 2434 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 82% | 33,765 psi | 53% | 2431 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 30,472 psi | 48% | 2349 fps | 99.5% |
| Alliant Reloder-25 | <<locked>> | 80% | 26,716 psi | 42% | 2257 fps | 95.2% |
| Alliant Reloder-26 | 92.5 gr | 80% | 32,866 psi | 52% | 2470 fps | 98.8% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 49,980 psi | 78% | 2677 fps | 95.1% |
| Bofors RP15 | <<locked>> | 86% | 35,882 psi | 56% | 2480 fps | 95.7% |
| Bofors RP3 | <<locked>> | 80% | 52,794 psi | 83% | 2664 fps | 100% |
| Bofors RP30 | <<locked>> | 94% | 38,101 psi | 60% | 2566 fps | 95.9% |
| Bofors RP5 | <<locked>> | 82% | 33,765 psi | 53% | 2431 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 45,861 psi | 72% | 2559 fps | 99% |
| Hodgdon H1000 | <<locked>> | 94% | 38,232 psi | 60% | 2520 fps | 95.9% |
| Hodgdon H380 | <<locked>> | 80% | 52,837 psi | 83% | 2684 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 48,196 psi | 76% | 2671 fps | 99.6% |
| Hodgdon H4350 | <<locked>> | 80% | 43,410 psi | 68% | 2549 fps | 98.1% |
| Hodgdon H4831 | <<locked>> | 90% | 41,568 psi | 65% | 2543 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 86% | 40,814 psi | 64% | 2526 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 38,667 psi | 61% | 2454 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 88% | 33,663 psi | 53% | 2497 fps | 95.4% |
| Hodgdon Superformance | <<locked>> | 80% | 43,526 psi | 68% | 2625 fps | 98.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,659 psi | 43% | 1506 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 53,693 psi | 84% | 2661 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 50,212 psi | 79% | 2605 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 48,950 psi | 77% | 2589 fps | 99.6% |
| IMR 4350 | <<locked>> | 80% | 41,481 psi | 65% | 2500 fps | 98.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 47,268 psi | 74% | 2585 fps | 99.4% |
| IMR 4831 | <<locked>> | 80% | 37,086 psi | 58% | 2434 fps | 99.6% |
| IMR 4955 Enduron | <<locked>> | 84% | 40,741 psi | 64% | 2487 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 86% | 39,813 psi | 62% | 2569 fps | 95.6% |
| Lovex S062 | <<locked>> | 80% | 54,085 psi | 85% | 2648 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 44,904 psi | 70% | 2539 fps | 99.8% |
| Lovex S070 | <<locked>> | 80% | 43,134 psi | 68% | 2530 fps | 99.1% |
| Lovex S071 | <<locked>> | 80% | 27,369 psi | 43% | 2205 fps | 95.2% |
| Norma 204 | <<locked>> | 80% | 41,118 psi | 64% | 2530 fps | 97.1% |
| Norma 217 | <<locked>> | 96% | 31,430 psi | 49% | 2441 fps | 95.3% |
| Norma MRP | 89.8 gr | 80% | 32,938 psi | 52% | 2441 fps | 96.3% |
| Norma URP | <<locked>> | 80% | 42,090 psi | 66% | 2546 fps | 99.9% |
| Ramshot Grand | <<locked>> | 84% | 38,551 psi | 60% | 2556 fps | 95.6% |
| Ramshot Hunter | <<locked>> | 80% | 40,799 psi | 64% | 2543 fps | 99.2% |
| Ramshot Magnum | <<locked>> | 84% | 33,504 psi | 53% | 2421 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,297 psi | 44% | 1542 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 52,591 psi | 82% | 2671 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 49,893 psi | 78% | 2713 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 42,438 psi | 67% | 2575 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 40,770 psi | 64% | 2592 fps | 99.8% |
| ReloadSwiss RS 76 | <<locked>> | 86% | 30,516 psi | 48% | 2408 fps | 95% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 41,553 psi | 65% | 2671 fps | 95.2% |
| Rottweil R 903 | <<locked>> | 80% | 49,719 psi | 78% | 2615 fps | 100% |
| Rottweil R 904 | <<locked>> | 82% | 39,653 psi | 62% | 2470 fps | 95.7% |
| Rottweil R 905 | <<locked>> | 80% | 35,012 psi | 55% | 2418 fps | 95.6% |
| Rottweil R 907 | <<locked>> | 80% | 45,861 psi | 72% | 2559 fps | 99% |
| Shooters World Long Rifle | <<locked>> | 80% | 44,904 psi | 70% | 2539 fps | 99.8% |
| Shooters World Precision | <<locked>> | 80% | 54,085 psi | 85% | 2648 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 43,134 psi | 68% | 2530 fps | 99.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 50,879 psi | 80% | 2671 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 50,270 psi | 79% | 2500 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 43,830 psi | 69% | 2487 fps | 99.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 34,679 psi | 54% | 2415 fps | 95.5% |
| Somchem S355 | <<locked>> | 80% | 49,734 psi | 78% | 2612 fps | 100% |
| Somchem S361 | <<locked>> | 84% | 43,062 psi | 67% | 2516 fps | 95.8% |
| Somchem S365 | <<locked>> | 80% | 38,899 psi | 61% | 2507 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 35,621 psi | 56% | 2408 fps | 96.7% |
| Unknown powder | <<locked>> | 80% | 45,078 psi | 71% | 2595 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 80% | 47,485 psi | 74% | 2539 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 43,453 psi | 68% | 2539 fps | 100% |
| Vihtavuori N165 | <<locked>> | 82% | 32,837 psi | 51% | 2339 fps | 95.3% |
| Vihtavuori N550 | <<locked>> | 80% | 42,859 psi | 67% | 2546 fps | 99.9% |
| Vihtavuori N555 | <<locked>> | 80% | 34,127 psi | 53% | 2421 fps | 99.4% |
| Vihtavuori N560 | 96.5 gr | 86% | 40,785 psi | 64% | 2602 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 92% | 40,393 psi | 63% | 2585 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 98% | 43,033 psi | 67% | 2680 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 42,409 psi | 66% | 2507 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 48,196 psi | 76% | 2671 fps | 99.6% |
| Winchester StaBALL HD | <<locked>> | 80% | 26,919 psi | 42% | 2356 fps | 99.5% |
| Winchester Supreme 780 | <<locked>> | 80% | 35,201 psi | 55% | 2398 fps | 95.5% |
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 87 powders for .378 Weath. Mag. loaded with the .375 | 300gr | Nosler Solid. Winchester StaBALL HD delivers the highest muzzle velocity at 2,920 fps; across all powders the maximum-charge window runs from 1,686 fps to 2,920 fps. ADI AR 2217 gives the best case fill at 100 %, and 87 of the 87 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 300.0 gr projectile in 0.375" calls for a 1:6.0 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. Alliant Reloder-26, Vihtavuori N560, Norma MRP rank at the top here: for .378 Weath. Mag. with the .375 | 300gr | Nosler Solid 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.