Load Specifications
Load data in caliber .378 Weath. Mag. with .375 | 270gr | Woodleigh RN SN bullet and 84 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Accurate High Country 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 3100 | <<locked>> | 98% | 57,711 psi | 90% | 2936 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 55,651 psi | 87% | 2920 fps | 100% |
| Accurate High Country | <<locked>> | 94% | 55,259 psi | 87% | 3031 fps | 98.7% |
| Accurate MAGPRO | <<locked>> | 96% | 56,173 psi | 88% | 3031 fps | 97.8% |
| ADI AR 2208 | <<locked>> | 84% | 57,305 psi | 90% | 2881 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 56,318 psi | 88% | 2972 fps | 99.3% |
| ADI AR 2213 | <<locked>> | 96% | 54,041 psi | 85% | 2972 fps | 98.3% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 45,092 psi | 71% | 2802 fps | 96.6% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 39,987 psi | 63% | 2759 fps | 98.3% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 56,492 psi | 89% | 2969 fps | 99.3% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 56,492 psi | 89% | 2969 fps | 99.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 55,013 psi | 86% | 2854 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 56,420 psi | 88% | 2976 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 57,653 psi | 90% | 2992 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 55,753 psi | 87% | 2959 fps | 99.3% |
| Alliant Reloder-22 | <<locked>> | 98% | 57,363 psi | 90% | 3028 fps | 99.6% |
| Alliant Reloder-23 | <<locked>> | 98% | 54,563 psi | 86% | 2946 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 50,415 psi | 79% | 2946 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 54,810 psi | 86% | 3038 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 56,405 psi | 88% | 2933 fps | 95.9% |
| Bofors RP15ᴾ | <<locked>> | 100% | 56,130 psi | 88% | 3009 fps | 99.4% |
| Bofors RP3 | <<locked>> | 82% | 55,999 psi | 88% | 2871 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 46,296 psi | 73% | 2874 fps | 97.4% |
| Bofors RP5 | <<locked>> | 98% | 57,363 psi | 90% | 3028 fps | 99.6% |
| Bofors RP7 | <<locked>> | 86% | 54,998 psi | 86% | 2867 fps | 99.6% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 49,647 psi | 78% | 2894 fps | 98.3% |
| Hodgdon H380 | <<locked>> | 82% | 56,043 psi | 88% | 2890 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 57,421 psi | 90% | 2976 fps | 100% |
| Hodgdon H4350 | <<locked>> | 86% | 56,666 psi | 89% | 2930 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 94% | 54,056 psi | 85% | 2913 fps | 97.7% |
| Hodgdon H4831 SC | <<locked>> | 96% | 56,753 psi | 89% | 2956 fps | 98.1% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 56,637 psi | 89% | 2894 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 49,284 psi | 77% | 3002 fps | 99.4% |
| Hodgdon Superformance | <<locked>> | 86% | 53,940 psi | 85% | 2956 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,869 psi | 58% | 1804 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 56,695 psi | 89% | 2864 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 56,304 psi | 88% | 2904 fps | 99.7% |
| IMR 4451 Enduron | <<locked>> | 86% | 56,565 psi | 89% | 2894 fps | 99.9% |
| IMR 4831 | <<locked>> | 90% | 55,927 psi | 88% | 2910 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 55,347 psi | 87% | 2900 fps | 98% |
| IMR 7828 SSC | <<locked>> | 98% | 55,419 psi | 87% | 3009 fps | 98.6% |
| Lovex S062 | <<locked>> | 82% | 57,072 psi | 89% | 2854 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 57,014 psi | 89% | 2890 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 55,085 psi | 86% | 2887 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 51,358 psi | 80% | 2841 fps | 99.9% |
| Norma 204 | <<locked>> | 90% | 57,319 psi | 90% | 2963 fps | 99.3% |
| Norma 217ᴾ | <<locked>> | 100% | 35,505 psi | 56% | 2680 fps | 96.1% |
| Norma MRP | <<locked>> | 96% | 57,232 psi | 90% | 3054 fps | 100% |
| Norma URP | <<locked>> | 88% | 54,201 psi | 85% | 2904 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 55,970 psi | 88% | 3028 fps | 99% |
| Ramshot Hunter | <<locked>> | 90% | 56,550 psi | 89% | 2963 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 54,070 psi | 85% | 2963 fps | 99.7% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,565 psi | 59% | 1847 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 55,709 psi | 87% | 2877 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 57,188 psi | 90% | 2979 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 55,579 psi | 87% | 2946 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 57,667 psi | 90% | 3028 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 49,603 psi | 78% | 2999 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 84% | 56,202 psi | 88% | 2871 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 54,244 psi | 85% | 2887 fps | 98.3% |
| Rottweil R 905 | <<locked>> | 94% | 55,187 psi | 86% | 2949 fps | 99.3% |
| Rottweil R 907 | <<locked>> | 86% | 54,998 psi | 86% | 2867 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 88% | 57,014 psi | 89% | 2890 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 57,072 psi | 89% | 2854 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 55,085 psi | 86% | 2887 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 57,638 psi | 90% | 2930 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 56,318 psi | 88% | 2740 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 56,376 psi | 88% | 2841 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 54,795 psi | 86% | 2946 fps | 99.3% |
| Somchem S355 | <<locked>> | 84% | 55,869 psi | 88% | 2864 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 55,854 psi | 88% | 2881 fps | 97.9% |
| Somchem S365 | <<locked>> | 92% | 57,740 psi | 90% | 2956 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 55,782 psi | 87% | 2923 fps | 99.7% |
| Vihtavuori N150 | <<locked>> | 86% | 57,188 psi | 90% | 2835 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 56,101 psi | 88% | 2897 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 55,230 psi | 87% | 2900 fps | 99.5% |
| Vihtavuori N550 | <<locked>> | 88% | 55,187 psi | 86% | 2900 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 57,072 psi | 89% | 2972 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 57,174 psi | 90% | 3048 fps | 98.5% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 52,736 psi | 83% | 2959 fps | 98% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 55,477 psi | 87% | 2854 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 57,711 psi | 90% | 2979 fps | 100% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 55,158 psi | 86% | 3081 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 55,796 psi | 87% | 2917 fps | 99.2% |
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% | 31,401 psi | 49% | 2441 fps | 96% |
| Accurate 4350 | <<locked>> | 80% | 42,351 psi | 66% | 2700 fps | 99.8% |
| Accurate High Country | 104.1 gr | 86% | 41,756 psi | 65% | 2782 fps | 95.7% |
| Accurate MAGPRO | <<locked>> | 90% | 45,440 psi | 71% | 2841 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 50,662 psi | 79% | 2782 fps | 100% |
| ADI AR 2209 | <<locked>> | 82% | 37,971 psi | 60% | 2625 fps | 95.4% |
| ADI AR 2213 | <<locked>> | 88% | 41,350 psi | 65% | 2730 fps | 95.1% |
| ADI AR 2217 | <<locked>> | 98% | 42,192 psi | 66% | 2740 fps | 95.6% |
| ADI AR 2225 | <<locked>> | 94% | 33,011 psi | 52% | 2575 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 38,218 psi | 60% | 2628 fps | 95.6% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 38,218 psi | 60% | 2628 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 51,648 psi | 81% | 2805 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 40,741 psi | 64% | 2707 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 46,673 psi | 73% | 2828 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 37,855 psi | 59% | 2621 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 86% | 38,319 psi | 60% | 2674 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 30,211 psi | 47% | 2474 fps | 98.9% |
| Alliant Reloder-25 | <<locked>> | 84% | 30,052 psi | 47% | 2487 fps | 96% |
| Alliant Reloder-26 | 99.8 gr | 80% | 32,605 psi | 51% | 2598 fps | 98% |
| Baschieri & Pellagri 109 | <<locked>> | 96% | 52,953 psi | 83% | 2877 fps | 95% |
| Bofors RP15 | <<locked>> | 88% | 38,043 psi | 60% | 2667 fps | 95.6% |
| Bofors RP3 | <<locked>> | 80% | 52,344 psi | 82% | 2818 fps | 100% |
| Bofors RP30 | <<locked>> | 96% | 40,509 psi | 63% | 2756 fps | 95.8% |
| Bofors RP5 | <<locked>> | 86% | 38,319 psi | 60% | 2674 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 45,643 psi | 72% | 2707 fps | 98.5% |
| Hodgdon H1000 | <<locked>> | 94% | 40,524 psi | 64% | 2707 fps | 95.7% |
| Hodgdon H380 | <<locked>> | 80% | 52,475 psi | 82% | 2838 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 44,048 psi | 69% | 2746 fps | 98.7% |
| Hodgdon H4350 | <<locked>> | 80% | 46,804 psi | 73% | 2762 fps | 98.2% |
| Hodgdon H4831 | <<locked>> | 88% | 44,222 psi | 69% | 2736 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 88% | 43,366 psi | 68% | 2720 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 38,377 psi | 60% | 2595 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 90% | 35,650 psi | 56% | 2684 fps | 95.2% |
| Hodgdon Superformance | <<locked>> | 80% | 43,236 psi | 68% | 2766 fps | 98.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,615 psi | 43% | 1614 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 53,330 psi | 84% | 2812 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 41,147 psi | 64% | 2635 fps | 97.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 46,992 psi | 74% | 2733 fps | 99% |
| IMR 4831 | <<locked>> | 80% | 40,451 psi | 63% | 2648 fps | 99.6% |
| IMR 4955 Enduron | <<locked>> | 86% | 43,149 psi | 68% | 2677 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 90% | 42,395 psi | 66% | 2766 fps | 95.6% |
| Lovex S062 | <<locked>> | 80% | 53,722 psi | 84% | 2805 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 44,556 psi | 70% | 2684 fps | 99.5% |
| Lovex S070 | <<locked>> | 80% | 42,844 psi | 67% | 2671 fps | 98.6% |
| Lovex S071 | <<locked>> | 84% | 30,748 psi | 48% | 2421 fps | 95.8% |
| Norma 204 | <<locked>> | 80% | 40,814 psi | 64% | 2667 fps | 96.3% |
| Norma 217 | <<locked>> | 98% | 33,214 psi | 52% | 2618 fps | 95% |
| Norma MRP | 96.8 gr | 80% | 32,648 psi | 51% | 2562 fps | 95.1% |
| Norma URP | <<locked>> | 80% | 41,785 psi | 65% | 2687 fps | 99.7% |
| Ramshot Grand | <<locked>> | 90% | 42,047 psi | 66% | 2772 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 40,538 psi | 64% | 2680 fps | 98.6% |
| Ramshot Magnum | <<locked>> | 88% | 34,853 psi | 55% | 2585 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,181 psi | 44% | 1654 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 52,228 psi | 82% | 2822 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 49,530 psi | 78% | 2871 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 42,148 psi | 66% | 2720 fps | 99.7% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 40,596 psi | 64% | 2733 fps | 99.5% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 34,809 psi | 55% | 2661 fps | 96.2% |
| Rottweil R 903 | <<locked>> | 80% | 49,371 psi | 77% | 2769 fps | 100% |
| Rottweil R 904 | <<locked>> | 84% | 42,105 psi | 66% | 2664 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 82% | 37,101 psi | 58% | 2605 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 80% | 45,643 psi | 72% | 2707 fps | 98.5% |
| Shooters World Long Rifle | <<locked>> | 80% | 44,556 psi | 70% | 2684 fps | 99.5% |
| Shooters World Precision | <<locked>> | 80% | 53,722 psi | 84% | 2805 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 42,844 psi | 67% | 2671 fps | 98.6% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 50,531 psi | 79% | 2825 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 49,951 psi | 78% | 2654 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 43,584 psi | 68% | 2628 fps | 98.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 36,767 psi | 58% | 2598 fps | 95.3% |
| Somchem S355 | <<locked>> | 80% | 49,371 psi | 77% | 2766 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 45,818 psi | 72% | 2710 fps | 95.8% |
| Somchem S365 | <<locked>> | 80% | 38,493 psi | 60% | 2648 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 35,288 psi | 55% | 2533 fps | 95.7% |
| Vihtavuori N150 | <<locked>> | 80% | 47,195 psi | 74% | 2690 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 43,149 psi | 68% | 2684 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 84% | 34,766 psi | 54% | 2516 fps | 95.1% |
| Vihtavuori N550 | <<locked>> | 80% | 42,540 psi | 67% | 2687 fps | 99.7% |
| Vihtavuori N555 | <<locked>> | 80% | 33,779 psi | 53% | 2549 fps | 98.9% |
| Vihtavuori N560 | <<locked>> | 88% | 43,410 psi | 68% | 2799 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 94% | 43,018 psi | 67% | 2779 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 42,192 psi | 66% | 2648 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 44,222 psi | 69% | 2749 fps | 98.7% |
| Winchester StaBALL HD | <<locked>> | 80% | 26,716 psi | 42% | 2467 fps | 98.8% |
| Winchester Supreme 780 | <<locked>> | 84% | 36,912 psi | 58% | 2572 fps | 95.2% |
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 84 powders for .378 Weath. Mag. loaded with the .375 | 270gr | Woodleigh RN SN. Winchester StaBALL HD delivers the highest muzzle velocity at 3,081 fps; across all powders the maximum-charge window runs from 1,804 fps to 3,081 fps. ADI AR 2217 gives the best case fill at 100 %, and 84 of the 84 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. 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, Accurate High Country, Norma MRP rank at the top here: for .378 Weath. Mag. with the .375 | 270gr | Woodleigh RN SN 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.