Load Specifications
Load data in caliber .378 Weath. Mag. with .375 | 300gr | Woodleigh HS bullet and 83 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N560, Norma MRP and Accurate MAGPRO.
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 3100 | <<locked>> | 96% | 54,592 psi | 86% | 2736 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 56,304 psi | 88% | 2769 fps | 100% |
| Accurate MAGPRO | <<locked>> | 96% | 56,840 psi | 89% | 2887 fps | 98.5% |
| ADI AR 2208 | <<locked>> | 82% | 54,389 psi | 85% | 2680 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 57,043 psi | 89% | 2825 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 96% | 54,563 psi | 86% | 2828 fps | 98.9% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 45,701 psi | 72% | 2671 fps | 97.6% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 40,451 psi | 63% | 2635 fps | 99.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 55,651 psi | 87% | 2700 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 57,188 psi | 90% | 2822 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 54,650 psi | 86% | 2789 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 56,405 psi | 88% | 2812 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 96% | 54,288 psi | 85% | 2825 fps | 99.6% |
| Alliant Reloder-23 | <<locked>> | 98% | 55,347 psi | 87% | 2795 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 50,879 psi | 80% | 2802 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 55,593 psi | 87% | 2887 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 56,753 psi | 89% | 2792 fps | 96.7% |
| Bofors RP15ᴾ | <<locked>> | 100% | 56,942 psi | 89% | 2864 fps | 99.8% |
| Bofors RP3 | <<locked>> | 82% | 56,623 psi | 89% | 2717 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 46,862 psi | 73% | 2740 fps | 98.3% |
| Bofors RP5 | <<locked>> | 96% | 54,288 psi | 85% | 2825 fps | 99.6% |
| Bofors RP7 | <<locked>> | 86% | 55,695 psi | 87% | 2720 fps | 99.9% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 50,256 psi | 79% | 2756 fps | 99% |
| Hodgdon H380 | <<locked>> | 82% | 56,710 psi | 89% | 2740 fps | 100% |
| Hodgdon H414 | <<locked>> | 86% | 54,476 psi | 85% | 2772 fps | 100% |
| Hodgdon H4350 | <<locked>> | 86% | 57,421 psi | 90% | 2782 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 94% | 54,679 psi | 86% | 2769 fps | 98.4% |
| Hodgdon H4831 SC | <<locked>> | 96% | 57,290 psi | 90% | 2808 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 57,377 psi | 90% | 2743 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 49,908 psi | 78% | 2861 fps | 99.8% |
| Hodgdon Superformance | <<locked>> | 86% | 54,607 psi | 86% | 2808 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,970 psi | 58% | 1690 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 57,290 psi | 90% | 2707 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 56,971 psi | 89% | 2756 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 86% | 57,159 psi | 90% | 2743 fps | 100% |
| IMR 4831 | <<locked>> | 90% | 56,681 psi | 89% | 2759 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 56,028 psi | 88% | 2756 fps | 98.7% |
| IMR 7828 SSC | <<locked>> | 98% | 55,956 psi | 88% | 2861 fps | 99.2% |
| Lovex S062 | <<locked>> | 82% | 57,711 psi | 90% | 2697 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 57,609 psi | 90% | 2736 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 55,622 psi | 87% | 2736 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 52,083 psi | 82% | 2703 fps | 100% |
| Norma 204 | <<locked>> | 88% | 54,288 psi | 85% | 2759 fps | 99.4% |
| Norma 217ᴾ | <<locked>> | 100% | 36,027 psi | 56% | 2566 fps | 97.4% |
| Norma MRP | <<locked>> | 94% | 54,070 psi | 85% | 2848 fps | 100% |
| Norma URP | <<locked>> | 88% | 54,781 psi | 86% | 2753 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 56,797 psi | 89% | 2884 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 90% | 57,217 psi | 90% | 2812 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 54,679 psi | 86% | 2818 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,739 psi | 59% | 1729 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 56,376 psi | 88% | 2726 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 54,041 psi | 85% | 2772 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 56,246 psi | 88% | 2795 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 54,505 psi | 85% | 2822 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 50,241 psi | 79% | 2861 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 45,121 psi | 71% | 2743 fps | 96.4% |
| Rottweil R 903 | <<locked>> | 84% | 56,811 psi | 89% | 2717 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 54,897 psi | 86% | 2743 fps | 98.9% |
| Rottweil R 905 | <<locked>> | 94% | 55,956 psi | 88% | 2805 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 86% | 55,695 psi | 87% | 2720 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 88% | 57,609 psi | 90% | 2736 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 57,711 psi | 90% | 2697 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 55,622 psi | 87% | 2736 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 54,607 psi | 86% | 2723 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 57,014 psi | 89% | 2589 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 57,029 psi | 89% | 2694 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 55,506 psi | 87% | 2799 fps | 99.7% |
| Somchem S355 | <<locked>> | 84% | 56,478 psi | 89% | 2710 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 56,420 psi | 88% | 2736 fps | 98.5% |
| Somchem S365 | <<locked>> | 90% | 54,868 psi | 86% | 2753 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 56,362 psi | 88% | 2776 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 84% | 54,230 psi | 85% | 2638 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 56,652 psi | 89% | 2743 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 55,869 psi | 88% | 2756 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 88% | 55,796 psi | 87% | 2753 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 54,273 psi | 85% | 2772 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 54,099 psi | 85% | 2844 fps | 98.6% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 53,505 psi | 84% | 2822 fps | 98.7% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 46,514 psi | 73% | 2753 fps | 96.1% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 56,188 psi | 88% | 2707 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 54,621 psi | 86% | 2772 fps | 100% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 56,086 psi | 88% | 2930 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 56,463 psi | 88% | 2772 fps | 99.6% |
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% | 31,952 psi | 50% | 2326 fps | 97.2% |
| Accurate 4350 | <<locked>> | 80% | 43,033 psi | 67% | 2562 fps | 100% |
| Accurate MAGPRO | 101.3 gr | 88% | 42,975 psi | 67% | 2651 fps | 95.6% |
| ADI AR 2208 | <<locked>> | 80% | 51,184 psi | 80% | 2631 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 36,027 psi | 56% | 2444 fps | 95.7% |
| ADI AR 2213 | <<locked>> | 86% | 39,175 psi | 61% | 2543 fps | 95.3% |
| ADI AR 2217 | <<locked>> | 96% | 40,045 psi | 63% | 2556 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 92% | 31,430 psi | 49% | 2408 fps | 95.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 52,330 psi | 82% | 2654 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 41,292 psi | 65% | 2569 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 47,384 psi | 74% | 2680 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 35,998 psi | 56% | 2441 fps | 95.8% |
| Alliant Reloder-22 | <<locked>> | 82% | 34,055 psi | 53% | 2438 fps | 95.2% |
| Alliant Reloder-23 | <<locked>> | 80% | 30,676 psi | 48% | 2356 fps | 99.6% |
| Alliant Reloder-25 | <<locked>> | 80% | 26,876 psi | 42% | 2264 fps | 95.3% |
| Alliant Reloder-26 | <<locked>> | 80% | 33,156 psi | 52% | 2480 fps | 98.9% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 50,285 psi | 79% | 2684 fps | 95.2% |
| Bofors RP15 | <<locked>> | 86% | 36,172 psi | 57% | 2487 fps | 95.9% |
| Bofors RP3 | <<locked>> | 80% | 53,026 psi | 83% | 2671 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 35,969 psi | 56% | 2516 fps | 95.1% |
| Bofors RP5 | <<locked>> | 82% | 34,055 psi | 53% | 2438 fps | 95.2% |
| Bofors RP7 | <<locked>> | 80% | 46,195 psi | 72% | 2569 fps | 99.1% |
| Hodgdon H1000 | <<locked>> | 90% | 35,998 psi | 56% | 2467 fps | 95% |
| Hodgdon H380 | <<locked>> | 80% | 53,156 psi | 83% | 2690 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 44,657 psi | 70% | 2608 fps | 99.3% |
| Hodgdon H4350 | <<locked>> | 80% | 47,384 psi | 74% | 2621 fps | 98.8% |
| Hodgdon H4831 | <<locked>> | 86% | 41,829 psi | 66% | 2549 fps | 95.6% |
| Hodgdon H4831 SC | <<locked>> | 86% | 41,089 psi | 64% | 2533 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 39,015 psi | 61% | 2464 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 88% | 33,895 psi | 53% | 2507 fps | 95.6% |
| Hodgdon Superformance | <<locked>> | 80% | 43,816 psi | 69% | 2631 fps | 99% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,688 psi | 43% | 1509 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 53,853 psi | 84% | 2661 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 41,655 psi | 65% | 2503 fps | 98.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 47,572 psi | 75% | 2592 fps | 99.5% |
| IMR 4831 | <<locked>> | 80% | 41,046 psi | 64% | 2513 fps | 99.9% |
| IMR 4955 Enduron | <<locked>> | 84% | 41,002 psi | 64% | 2497 fps | 95.5% |
| IMR 7828 SSC | <<locked>> | 88% | 40,190 psi | 63% | 2579 fps | 95.8% |
| Lovex S062 | <<locked>> | 80% | 54,288 psi | 85% | 2651 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 45,107 psi | 71% | 2546 fps | 99.8% |
| Lovex S070 | <<locked>> | 80% | 43,323 psi | 68% | 2533 fps | 99.1% |
| Lovex S071 | <<locked>> | 80% | 27,572 psi | 43% | 2211 fps | 95.3% |
| Norma 204 | <<locked>> | 80% | 41,394 psi | 65% | 2536 fps | 97.2% |
| Norma 217 | <<locked>> | 96% | 31,633 psi | 50% | 2448 fps | 95.4% |
| Norma MRP | 90.4 gr | 80% | 33,228 psi | 52% | 2448 fps | 96.5% |
| Norma URP | <<locked>> | 80% | 42,293 psi | 66% | 2552 fps | 99.9% |
| Ramshot Grand | <<locked>> | 86% | 37,057 psi | 58% | 2523 fps | 95.1% |
| Ramshot Hunter | <<locked>> | 80% | 41,133 psi | 64% | 2549 fps | 99.2% |
| Ramshot Magnum | <<locked>> | 86% | 32,924 psi | 52% | 2408 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,195 psi | 44% | 1542 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 52,924 psi | 83% | 2677 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 50,270 psi | 79% | 2720 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 42,743 psi | 67% | 2582 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 41,075 psi | 64% | 2598 fps | 99.8% |
| ReloadSwiss RS 76 | <<locked>> | 86% | 30,792 psi | 48% | 2421 fps | 95.2% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 41,974 psi | 66% | 2680 fps | 95.4% |
| Rottweil R 903 | <<locked>> | 80% | 49,951 psi | 78% | 2621 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 37,492 psi | 59% | 2428 fps | 95% |
| Rottweil R 905 | <<locked>> | 80% | 35,215 psi | 55% | 2425 fps | 95.7% |
| Rottweil R 907 | <<locked>> | 80% | 46,195 psi | 72% | 2569 fps | 99.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 45,107 psi | 71% | 2546 fps | 99.8% |
| Shooters World Precision | <<locked>> | 80% | 54,288 psi | 85% | 2651 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 43,323 psi | 68% | 2533 fps | 99.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 51,198 psi | 80% | 2677 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 50,473 psi | 79% | 2507 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 44,150 psi | 69% | 2493 fps | 99.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 34,882 psi | 55% | 2421 fps | 95.6% |
| Somchem S355 | <<locked>> | 80% | 49,937 psi | 78% | 2618 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 40,524 psi | 64% | 2467 fps | 95.1% |
| Somchem S365 | <<locked>> | 80% | 39,131 psi | 61% | 2513 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 35,810 psi | 56% | 2411 fps | 96.8% |
| Vihtavuori N150 | <<locked>> | 80% | 47,718 psi | 75% | 2546 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 43,772 psi | 69% | 2549 fps | 100% |
| Vihtavuori N165 | <<locked>> | 82% | 33,112 psi | 52% | 2346 fps | 95.4% |
| Vihtavuori N550 | <<locked>> | 80% | 43,207 psi | 68% | 2552 fps | 99.9% |
| Vihtavuori N555 | <<locked>> | 80% | 34,374 psi | 54% | 2425 fps | 99.5% |
| Vihtavuori N560 | 97.1 gr | 86% | 41,089 psi | 64% | 2608 fps | 95.6% |
| Vihtavuori N565 | <<locked>> | 90% | 38,145 psi | 60% | 2539 fps | 95% |
| Vihtavuori N568 | <<locked>> | 98% | 43,497 psi | 68% | 2694 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 42,699 psi | 67% | 2513 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 44,788 psi | 70% | 2612 fps | 99.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 27,166 psi | 43% | 2365 fps | 99.6% |
| Winchester Supreme 780 | <<locked>> | 82% | 34,940 psi | 55% | 2395 fps | 95.4% |
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 83 powders for .378 Weath. Mag. loaded with the .375 | 300gr | Woodleigh HS. Winchester StaBALL HD delivers the highest muzzle velocity at 2,930 fps; across all powders the maximum-charge window runs from 1,690 fps to 2,930 fps. ADI AR 2217 gives the best case fill at 100 %, and 83 of the 83 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. Vihtavuori N560, Norma MRP, Accurate MAGPRO rank at the top here: for .378 Weath. Mag. with the .375 | 300gr | Woodleigh HS 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.