Load Specifications
Load data in caliber .378 Weath. Mag. with .375 | 250gr | NorthFork Bonded Core bullet and 90 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Norma MRP and Vihtavuori N560.
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: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 82% | 56,681 psi | 89% | 2881 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 57,667 psi | 90% | 2959 fps | 99.3% |
| Accurate 3100ᴾ | <<locked>> | 100% | 56,202 psi | 88% | 3009 fps | 99.9% |
| Accurate 4064 | <<locked>> | 84% | 57,043 psi | 89% | 2940 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 54,375 psi | 85% | 3005 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 54,462 psi | 85% | 3097 fps | 96.5% |
| ADI AR 2208 | <<locked>> | 86% | 56,913 psi | 89% | 2976 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 55,259 psi | 87% | 3048 fps | 98.6% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 56,681 psi | 89% | 3104 fps | 97.8% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 56,536 psi | 89% | 3107 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 54,331 psi | 85% | 2946 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 54,491 psi | 85% | 2969 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 55,042 psi | 86% | 3061 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 56,463 psi | 88% | 3084 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 54,636 psi | 86% | 3035 fps | 98.5% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 55,767 psi | 87% | 3100 fps | 98.8% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 52,692 psi | 83% | 3025 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 45,687 psi | 72% | 2953 fps | 99.6% |
| Alliant Reloder-26 | <<locked>> | 98% | 56,782 psi | 89% | 3173 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 51,024 psi | 80% | 3018 fps | 98% |
| Bofors RP3 | <<locked>> | 84% | 55,187 psi | 86% | 2963 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 55,767 psi | 87% | 3100 fps | 98.8% |
| Bofors RP7 | <<locked>> | 88% | 54,549 psi | 85% | 2953 fps | 99.1% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 45,484 psi | 71% | 2887 fps | 96% |
| Hodgdon H380 | <<locked>> | 84% | 55,579 psi | 87% | 2982 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 56,521 psi | 89% | 3058 fps | 99.6% |
| Hodgdon H4350 | <<locked>> | 88% | 56,028 psi | 88% | 3015 fps | 98.9% |
| Hodgdon H4831 | <<locked>> | 98% | 56,768 psi | 89% | 3045 fps | 97.2% |
| Hodgdon H4831 SC | <<locked>> | 98% | 55,622 psi | 87% | 3025 fps | 97% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 55,535 psi | 87% | 2982 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 56,884 psi | 89% | 3015 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 44,860 psi | 70% | 2992 fps | 97.5% |
| Hodgdon Superformance | <<locked>> | 90% | 56,898 psi | 89% | 3097 fps | 99.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,564 psi | 57% | 1860 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 57,276 psi | 90% | 2976 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 56,362 psi | 88% | 2956 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 55,332 psi | 87% | 2940 fps | 99.4% |
| IMR 4350 | <<locked>> | 92% | 55,593 psi | 87% | 2986 fps | 99.2% |
| IMR 4451 Enduron | <<locked>> | 88% | 56,057 psi | 88% | 2979 fps | 99.5% |
| IMR 4831 | <<locked>> | 92% | 54,839 psi | 86% | 2992 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 55,883 psi | 88% | 2995 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 54,679 psi | 86% | 2972 fps | 97% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 54,128 psi | 85% | 3074 fps | 97.4% |
| Lovex S062 | <<locked>> | 84% | 56,637 psi | 89% | 2949 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 56,318 psi | 88% | 2976 fps | 99.9% |
| Lovex S070 | <<locked>> | 92% | 57,667 psi | 90% | 3018 fps | 99.7% |
| Lovex S071ᴾ | <<locked>> | 100% | 46,630 psi | 73% | 2858 fps | 99.1% |
| Norma 203B | <<locked>> | 84% | 57,363 psi | 90% | 3009 fps | 100% |
| Norma 204 | <<locked>> | 92% | 56,492 psi | 89% | 3041 fps | 98.6% |
| Norma MRP | <<locked>> | 98% | 55,405 psi | 87% | 3127 fps | 99.6% |
| Norma URP | <<locked>> | 92% | 56,579 psi | 89% | 3041 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 54,578 psi | 86% | 2979 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 54,534 psi | 85% | 3091 fps | 97.9% |
| Ramshot Hunter | <<locked>> | 92% | 55,477 psi | 87% | 3045 fps | 99.9% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 48,820 psi | 77% | 2963 fps | 98.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,202 psi | 58% | 1903 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 55,332 psi | 87% | 2966 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 55,811 psi | 87% | 3074 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 54,302 psi | 85% | 3025 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 56,478 psi | 89% | 3114 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 44,860 psi | 70% | 2982 fps | 98.5% |
| Rottweil R 902 | <<locked>> | 82% | 55,158 psi | 86% | 2910 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 55,317 psi | 87% | 2959 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 56,985 psi | 89% | 3018 fps | 97.9% |
| Rottweil R 905 | <<locked>> | 98% | 57,580 psi | 90% | 3081 fps | 99% |
| Rottweil R 907 | <<locked>> | 88% | 54,549 psi | 85% | 2953 fps | 99.1% |
| Shooters World Long Rifle | <<locked>> | 90% | 56,318 psi | 88% | 2976 fps | 99.9% |
| Shooters World Precision | <<locked>> | 84% | 56,637 psi | 89% | 2949 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 57,667 psi | 90% | 3018 fps | 99.7% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 56,869 psi | 89% | 3018 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 56,188 psi | 88% | 2838 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 55,956 psi | 88% | 2927 fps | 99.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 57,087 psi | 89% | 3074 fps | 98.9% |
| Somchem S355 | <<locked>> | 86% | 55,172 psi | 86% | 2956 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 55,114 psi | 86% | 2953 fps | 96.8% |
| Somchem S365 | <<locked>> | 94% | 56,260 psi | 88% | 3045 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 54,607 psi | 86% | 2995 fps | 99.1% |
| Vihtavuori N135 | <<locked>> | 82% | 55,608 psi | 87% | 2864 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 55,709 psi | 87% | 2881 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 56,463 psi | 88% | 2927 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 55,129 psi | 86% | 2982 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 53,954 psi | 85% | 2969 fps | 98.8% |
| Vihtavuori N540 | <<locked>> | 84% | 57,508 psi | 90% | 2927 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 54,230 psi | 85% | 2986 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 55,216 psi | 87% | 3051 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 55,579 psi | 87% | 3117 fps | 97.3% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 54,752 psi | 86% | 2943 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 56,710 psi | 89% | 3061 fps | 99.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 48,095 psi | 75% | 3094 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 54,636 psi | 86% | 2989 fps | 98.4% |
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 2495 | <<locked>> | 80% | 53,156 psi | 83% | 2835 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 50,604 psi | 79% | 2844 fps | 98.4% |
| Accurate 3100 | <<locked>> | 84% | 32,532 psi | 51% | 2552 fps | 95.4% |
| Accurate 4064 | <<locked>> | 80% | 50,372 psi | 79% | 2841 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 38,522 psi | 60% | 2713 fps | 98.8% |
| Accurate MAGPRO | <<locked>> | 96% | 50,734 psi | 80% | 3031 fps | 95.6% |
| ADI AR 2208 | <<locked>> | 80% | 47,340 psi | 74% | 2818 fps | 100% |
| ADI AR 2209 | <<locked>> | 88% | 42,540 psi | 67% | 2812 fps | 95.8% |
| ADI AR 2213 | <<locked>> | 94% | 46,325 psi | 73% | 2913 fps | 95.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 52,649 psi | 83% | 3045 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 47,993 psi | 75% | 2844 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 51,082 psi | 80% | 2913 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 37,463 psi | 59% | 2723 fps | 98.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 42,583 psi | 67% | 2851 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 42,221 psi | 66% | 2802 fps | 95.8% |
| Alliant Reloder-22 | <<locked>> | 90% | 39,842 psi | 62% | 2795 fps | 95.2% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,528 psi | 43% | 2470 fps | 96.9% |
| Alliant Reloder-25 | <<locked>> | 88% | 31,227 psi | 49% | 2592 fps | 95.2% |
| Alliant Reloder-26 | 97.7 gr | 80% | 29,428 psi | 46% | 2582 fps | 95.2% |
| Bofors RP15 | <<locked>> | 94% | 41,989 psi | 66% | 2841 fps | 95.8% |
| Bofors RP3 | <<locked>> | 80% | 48,341 psi | 76% | 2858 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 39,842 psi | 62% | 2795 fps | 95.2% |
| Bofors RP7 | <<locked>> | 80% | 42,482 psi | 67% | 2726 fps | 96.9% |
| Hodgdon H1000 | <<locked>> | 98% | 42,496 psi | 67% | 2822 fps | 95% |
| Hodgdon H380 | <<locked>> | 80% | 48,646 psi | 76% | 2867 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 80% | 40,437 psi | 63% | 2759 fps | 97% |
| Hodgdon H4350 | <<locked>> | 80% | 43,323 psi | 68% | 2779 fps | 96.4% |
| Hodgdon H4831 | <<locked>> | 94% | 49,603 psi | 78% | 2920 fps | 95.6% |
| Hodgdon H4831 SC | <<locked>> | 94% | 48,617 psi | 76% | 2904 fps | 95.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,012 psi | 55% | 2612 fps | 99.3% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 53,142 psi | 83% | 2963 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 39,349 psi | 62% | 2854 fps | 95.4% |
| Hodgdon Superformance | <<locked>> | 80% | 39,421 psi | 62% | 2769 fps | 96.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,282 psi | 43% | 1663 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 53,708 psi | 84% | 2923 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 49,763 psi | 78% | 2851 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 51,938 psi | 81% | 2884 fps | 99.1% |
| IMR 4350 | <<locked>> | 80% | 38,145 psi | 60% | 2651 fps | 95.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 43,859 psi | 69% | 2759 fps | 97.7% |
| IMR 4831 | <<locked>> | 80% | 37,086 psi | 58% | 2664 fps | 98.5% |
| IMR 4895 | <<locked>> | 80% | 52,417 psi | 82% | 2943 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 48,254 psi | 76% | 2861 fps | 95.5% |
| IMR 7828 SSC | <<locked>> | 96% | 47,282 psi | 74% | 2949 fps | 95.8% |
| Lovex S062 | <<locked>> | 80% | 50,053 psi | 78% | 2848 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,408 psi | 65% | 2707 fps | 98.3% |
| Lovex S070 | <<locked>> | 80% | 39,653 psi | 62% | 2687 fps | 96.9% |
| Lovex S071 | <<locked>> | 88% | 31,662 psi | 50% | 2530 fps | 95% |
| Norma 203B | <<locked>> | 80% | 50,444 psi | 79% | 2900 fps | 100% |
| Norma 204 | <<locked>> | 84% | 43,033 psi | 67% | 2799 fps | 95.8% |
| Norma MRP | 101.9 gr | 86% | 36,463 psi | 57% | 2746 fps | 95.5% |
| Norma URP | <<locked>> | 80% | 38,319 psi | 60% | 2707 fps | 98.6% |
| Ramshot Big Game | <<locked>> | 80% | 51,024 psi | 80% | 2927 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 44,048 psi | 69% | 2894 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 80% | 37,115 psi | 58% | 2690 fps | 96.9% |
| Ramshot Magnum | <<locked>> | 94% | 39,204 psi | 61% | 2766 fps | 95.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,818 psi | 44% | 1703 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 48,617 psi | 76% | 2851 fps | 99.1% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 45,208 psi | 71% | 2904 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 38,348 psi | 60% | 2733 fps | 98.5% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 37,144 psi | 58% | 2740 fps | 98% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 36,347 psi | 57% | 2772 fps | 95.3% |
| Rottweil R 902 | <<locked>> | 80% | 51,866 psi | 81% | 2861 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 45,614 psi | 71% | 2802 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 44,092 psi | 69% | 2789 fps | 95% |
| Rottweil R 905 | <<locked>> | 88% | 41,379 psi | 65% | 2785 fps | 95.7% |
| Rottweil R 907 | <<locked>> | 80% | 42,482 psi | 67% | 2726 fps | 96.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,408 psi | 65% | 2707 fps | 98.3% |
| Shooters World Precision | <<locked>> | 80% | 50,053 psi | 78% | 2848 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 39,653 psi | 62% | 2687 fps | 96.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 46,673 psi | 73% | 2854 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 46,615 psi | 73% | 2697 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 40,422 psi | 63% | 2648 fps | 97% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 40,988 psi | 64% | 2779 fps | 95.6% |
| Somchem S355 | <<locked>> | 80% | 45,832 psi | 72% | 2799 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 48,327 psi | 76% | 2835 fps | 95.2% |
| Somchem S365 | <<locked>> | 80% | 34,795 psi | 55% | 2664 fps | 99.9% |
| Somchem S385 | <<locked>> | 84% | 36,811 psi | 58% | 2654 fps | 95.1% |
| Vihtavuori N135 | <<locked>> | 80% | 52,170 psi | 82% | 2818 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 52,359 psi | 82% | 2835 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 43,787 psi | 69% | 2726 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 39,624 psi | 62% | 2703 fps | 98.9% |
| Vihtavuori N165 | <<locked>> | 90% | 38,711 psi | 61% | 2687 fps | 95.4% |
| Vihtavuori N540 | <<locked>> | 80% | 50,546 psi | 79% | 2828 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 39,131 psi | 61% | 2707 fps | 98.6% |
| Vihtavuori N555 | <<locked>> | 80% | 30,472 psi | 48% | 2549 fps | 97% |
| Vihtavuori N560 | 111.4 gr | 94% | 48,501 psi | 76% | 2989 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 38,827 psi | 61% | 2674 fps | 99.9% |
| Winchester 760 | <<locked>> | 80% | 40,596 psi | 64% | 2762 fps | 97% |
| Winchester StaBALL HD | <<locked>> | 80% | 24,323 psi | 38% | 2438 fps | 95.6% |
| Winchester Supreme 780 | <<locked>> | 90% | 41,321 psi | 65% | 2749 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 90 powders for .378 Weath. Mag. loaded with the .375 | 250gr | NorthFork Bonded Core. Alliant Reloder-26 delivers the highest muzzle velocity at 3,173 fps; across all powders the maximum-charge window runs from 1,860 fps to 3,173 fps. Accurate 3100 gives the best case fill at 100 %, and 90 of the 90 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 250.0 gr projectile in 0.375" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, Alliant Reloder-22 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, Norma MRP, Vihtavuori N560 rank at the top here: for .378 Weath. Mag. with the .375 | 250gr | NorthFork Bonded Core 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.