Load Specifications
Load data in caliber .378 Weath. Mag. with .375 | 275gr | SUS-TAC HP bullet and 92 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% | 57,217 psi | 90% | 2740 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 54,549 psi | 85% | 2769 fps | 99.3% |
| Accurate 3100ᴾ | <<locked>> | 100% | 56,478 psi | 89% | 2871 fps | 100% |
| Accurate 4064 | <<locked>> | 84% | 57,725 psi | 90% | 2795 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 54,926 psi | 86% | 2864 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 54,897 psi | 86% | 2966 fps | 97.3% |
| ADI AR 2208 | <<locked>> | 86% | 57,290 psi | 90% | 2831 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 55,680 psi | 87% | 2913 fps | 99% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 57,043 psi | 89% | 2969 fps | 98.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 36,709 psi | 58% | 2631 fps | 96.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 57,130 psi | 90% | 2963 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 54,810 psi | 86% | 2805 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 55,042 psi | 86% | 2828 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 55,680 psi | 87% | 2920 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 56,913 psi | 89% | 2940 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 55,143 psi | 86% | 2904 fps | 99% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 56,173 psi | 88% | 2963 fps | 99.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 53,098 psi | 83% | 2884 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 46,180 psi | 72% | 2828 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 98% | 57,246 psi | 90% | 3031 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 51,503 psi | 81% | 2887 fps | 98.6% |
| Bofors RP3 | <<locked>> | 84% | 55,767 psi | 87% | 2822 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 41,930 psi | 66% | 2746 fps | 95.9% |
| Bofors RP5ᴾ | <<locked>> | 100% | 56,173 psi | 88% | 2963 fps | 99.3% |
| Bofors RP7 | <<locked>> | 88% | 54,955 psi | 86% | 2815 fps | 99.5% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 45,774 psi | 72% | 2766 fps | 96.9% |
| Hodgdon H380 | <<locked>> | 84% | 55,927 psi | 88% | 2841 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 57,000 psi | 89% | 2920 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 88% | 56,579 psi | 89% | 2877 fps | 99.3% |
| Hodgdon H4831 | <<locked>> | 98% | 57,217 psi | 90% | 2910 fps | 97.8% |
| Hodgdon H4831 SC | <<locked>> | 98% | 56,115 psi | 88% | 2894 fps | 97.6% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 55,985 psi | 88% | 2838 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 57,421 psi | 90% | 2874 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 45,121 psi | 71% | 2867 fps | 98.3% |
| Hodgdon Superformance | <<locked>> | 90% | 57,348 psi | 90% | 2959 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,593 psi | 57% | 1752 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 56,898 psi | 89% | 2815 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 55,767 psi | 87% | 2802 fps | 99.7% |
| IMR 4350 | <<locked>> | 92% | 56,028 psi | 88% | 2848 fps | 99.6% |
| IMR 4451 Enduron | <<locked>> | 88% | 56,478 psi | 89% | 2838 fps | 99.8% |
| IMR 4831 | <<locked>> | 92% | 55,332 psi | 87% | 2854 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 56,478 psi | 89% | 2854 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 55,042 psi | 86% | 2841 fps | 97.6% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 54,476 psi | 85% | 2943 fps | 98.1% |
| Lovex S062 | <<locked>> | 84% | 57,174 psi | 90% | 2805 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 56,768 psi | 89% | 2835 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 54,621 psi | 86% | 2828 fps | 99.8% |
| Lovex S071ᴾ | <<locked>> | 100% | 47,108 psi | 74% | 2730 fps | 99.5% |
| Norma 203B | <<locked>> | 82% | 54,389 psi | 85% | 2815 fps | 100% |
| Norma 204 | <<locked>> | 92% | 56,869 psi | 89% | 2904 fps | 99% |
| Norma MRP | <<locked>> | 98% | 55,956 psi | 88% | 2989 fps | 99.9% |
| Norma URP | <<locked>> | 92% | 57,174 psi | 90% | 2900 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 55,100 psi | 86% | 2841 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 55,100 psi | 86% | 2959 fps | 98.5% |
| Ramshot Hunter | <<locked>> | 92% | 55,840 psi | 88% | 2904 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 49,182 psi | 77% | 2835 fps | 98.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,318 psi | 58% | 1791 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 55,840 psi | 88% | 2828 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 56,420 psi | 88% | 2930 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 54,752 psi | 86% | 2887 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 56,927 psi | 89% | 2972 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 45,194 psi | 71% | 2864 fps | 99.1% |
| Rottweil R 902 | <<locked>> | 82% | 55,535 psi | 87% | 2766 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 55,811 psi | 87% | 2818 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 57,334 psi | 90% | 2881 fps | 98.4% |
| Rottweil R 905 | <<locked>> | 96% | 54,375 psi | 85% | 2887 fps | 99% |
| Rottweil R 907 | <<locked>> | 88% | 54,955 psi | 86% | 2815 fps | 99.5% |
| Shooters World Long Rifle | <<locked>> | 90% | 56,768 psi | 89% | 2835 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 57,174 psi | 90% | 2805 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 54,621 psi | 86% | 2828 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 57,348 psi | 90% | 2877 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 56,492 psi | 89% | 2697 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 56,405 psi | 88% | 2789 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 57,595 psi | 90% | 2936 fps | 99.4% |
| Somchem S355 | <<locked>> | 86% | 55,637 psi | 87% | 2812 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 55,521 psi | 87% | 2822 fps | 97.4% |
| Somchem S365 | <<locked>> | 94% | 56,710 psi | 89% | 2900 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 55,013 psi | 86% | 2864 fps | 99.5% |
| Vihtavuori N135 | <<locked>> | 82% | 56,057 psi | 88% | 2720 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 56,159 psi | 88% | 2740 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 56,956 psi | 89% | 2785 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 55,637 psi | 87% | 2841 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 54,259 psi | 85% | 2838 fps | 99.2% |
| Vihtavuori N540 | <<locked>> | 82% | 54,404 psi | 85% | 2740 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 54,752 psi | 86% | 2848 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 55,782 psi | 87% | 2913 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 56,144 psi | 88% | 2982 fps | 98% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 47,892 psi | 75% | 2831 fps | 96.6% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 55,143 psi | 86% | 2805 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 57,145 psi | 90% | 2920 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 48,544 psi | 76% | 2956 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 55,085 psi | 86% | 2858 fps | 98.9% |
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% | 53,693 psi | 84% | 2694 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 50,995 psi | 80% | 2713 fps | 98.9% |
| Accurate 3100 | <<locked>> | 82% | 30,806 psi | 48% | 2392 fps | 95.5% |
| Accurate 4064 | <<locked>> | 80% | 50,865 psi | 80% | 2703 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 39,015 psi | 61% | 2592 fps | 99.3% |
| Accurate MAGPRO | <<locked>> | 94% | 47,659 psi | 75% | 2841 fps | 95.6% |
| ADI AR 2208 | <<locked>> | 80% | 47,674 psi | 75% | 2684 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 40,190 psi | 63% | 2628 fps | 95.8% |
| ADI AR 2213 | <<locked>> | 92% | 43,758 psi | 69% | 2730 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 98% | 34,505 psi | 54% | 2572 fps | 95.6% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 53,171 psi | 83% | 2904 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 48,341 psi | 76% | 2707 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 51,576 psi | 81% | 2776 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 37,840 psi | 59% | 2602 fps | 99.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 43,033 psi | 67% | 2723 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 37,492 psi | 59% | 2569 fps | 95% |
| Alliant Reloder-22 | <<locked>> | 88% | 37,724 psi | 59% | 2621 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,891 psi | 44% | 2369 fps | 97.9% |
| Alliant Reloder-25 | <<locked>> | 86% | 29,588 psi | 46% | 2431 fps | 95.3% |
| Alliant Reloder-26 | 91.6 gr | 80% | 29,718 psi | 47% | 2480 fps | 96.5% |
| Bofors RP15 | <<locked>> | 92% | 39,813 psi | 62% | 2667 fps | 95.9% |
| Bofors RP3 | <<locked>> | 80% | 48,907 psi | 77% | 2723 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 39,305 psi | 62% | 2687 fps | 95% |
| Bofors RP5 | <<locked>> | 88% | 37,724 psi | 59% | 2621 fps | 95.3% |
| Bofors RP7 | <<locked>> | 80% | 42,902 psi | 67% | 2605 fps | 97.7% |
| Hodgdon H1000 | <<locked>> | 96% | 40,030 psi | 63% | 2644 fps | 95% |
| Hodgdon H380 | <<locked>> | 80% | 49,124 psi | 77% | 2736 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 80% | 40,959 psi | 64% | 2638 fps | 97.8% |
| Hodgdon H4350 | <<locked>> | 80% | 43,816 psi | 69% | 2657 fps | 97.2% |
| Hodgdon H4831 | <<locked>> | 92% | 46,702 psi | 73% | 2736 fps | 95.6% |
| Hodgdon H4831 SC | <<locked>> | 92% | 45,847 psi | 72% | 2720 fps | 95.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,505 psi | 56% | 2497 fps | 99.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 53,621 psi | 84% | 2818 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 94% | 37,260 psi | 58% | 2680 fps | 95.5% |
| Hodgdon Superformance | <<locked>> | 80% | 39,813 psi | 62% | 2651 fps | 97.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,340 psi | 43% | 1562 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 50,169 psi | 79% | 2717 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 52,475 psi | 82% | 2749 fps | 99.5% |
| IMR 4350 | <<locked>> | 80% | 38,493 psi | 60% | 2533 fps | 96.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 44,208 psi | 69% | 2631 fps | 98.3% |
| IMR 4831 | <<locked>> | 80% | 37,492 psi | 59% | 2546 fps | 99.1% |
| IMR 4895 | <<locked>> | 80% | 52,939 psi | 83% | 2802 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 45,745 psi | 72% | 2680 fps | 95.6% |
| IMR 7828 SSC | <<locked>> | 94% | 44,657 psi | 70% | 2762 fps | 95.8% |
| Lovex S062 | <<locked>> | 80% | 50,488 psi | 79% | 2710 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,800 psi | 66% | 2582 fps | 98.9% |
| Lovex S070 | <<locked>> | 80% | 40,016 psi | 63% | 2566 fps | 97.7% |
| Lovex S071 | <<locked>> | 86% | 30,037 psi | 47% | 2369 fps | 95.2% |
| Norma 203B | <<locked>> | 80% | 50,952 psi | 80% | 2762 fps | 100% |
| Norma 204 | <<locked>> | 82% | 40,582 psi | 64% | 2618 fps | 95.8% |
| Norma MRP | 93.4 gr | 84% | 34,432 psi | 54% | 2572 fps | 95.6% |
| Norma URP | <<locked>> | 80% | 38,711 psi | 61% | 2585 fps | 99.2% |
| Ramshot Big Game | <<locked>> | 80% | 51,445 psi | 81% | 2785 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 41,365 psi | 65% | 2707 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 80% | 37,507 psi | 59% | 2575 fps | 97.7% |
| Ramshot Magnum | <<locked>> | 92% | 36,825 psi | 58% | 2589 fps | 95.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,934 psi | 44% | 1601 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 49,124 psi | 77% | 2723 fps | 99.5% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 45,672 psi | 72% | 2769 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 38,754 psi | 61% | 2612 fps | 99.1% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 37,521 psi | 59% | 2621 fps | 98.7% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 34,185 psi | 54% | 2595 fps | 95.3% |
| Rottweil R 902 | <<locked>> | 80% | 52,359 psi | 82% | 2720 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 46,006 psi | 72% | 2671 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 41,727 psi | 65% | 2612 fps | 95% |
| Rottweil R 905 | <<locked>> | 86% | 39,044 psi | 61% | 2608 fps | 95.8% |
| Rottweil R 907 | <<locked>> | 80% | 42,902 psi | 67% | 2605 fps | 97.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,800 psi | 66% | 2582 fps | 98.9% |
| Shooters World Precision | <<locked>> | 80% | 50,488 psi | 79% | 2710 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 40,016 psi | 63% | 2566 fps | 97.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 47,123 psi | 74% | 2723 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 47,036 psi | 74% | 2566 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 40,843 psi | 64% | 2530 fps | 97.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 38,682 psi | 61% | 2602 fps | 95.7% |
| Somchem S355 | <<locked>> | 80% | 46,253 psi | 72% | 2667 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 45,556 psi | 71% | 2654 fps | 95.2% |
| Somchem S365 | <<locked>> | 80% | 35,273 psi | 55% | 2546 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 34,853 psi | 55% | 2484 fps | 95.2% |
| Vihtavuori N135 | <<locked>> | 80% | 52,707 psi | 83% | 2677 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 52,750 psi | 83% | 2694 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 44,164 psi | 69% | 2595 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 40,074 psi | 63% | 2582 fps | 99.3% |
| Vihtavuori N165 | <<locked>> | 88% | 36,666 psi | 57% | 2520 fps | 95.5% |
| Vihtavuori N540 | <<locked>> | 80% | 51,039 psi | 80% | 2690 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 39,581 psi | 62% | 2585 fps | 99.2% |
| Vihtavuori N555 | <<locked>> | 80% | 30,908 psi | 48% | 2444 fps | 97.9% |
| Vihtavuori N560 | 102.3 gr | 92% | 45,687 psi | 72% | 2799 fps | 95.7% |
| Vihtavuori N565 | <<locked>> | 98% | 44,831 psi | 70% | 2776 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 39,102 psi | 61% | 2549 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 41,075 psi | 64% | 2644 fps | 97.8% |
| Winchester StaBALL HD | <<locked>> | 80% | 24,613 psi | 39% | 2352 fps | 97.2% |
| Winchester Supreme 780 | <<locked>> | 88% | 38,986 psi | 61% | 2575 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 92 powders for .378 Weath. Mag. loaded with the .375 | 275gr | SUS-TAC HP. Alliant Reloder-26 delivers the highest muzzle velocity at 3,031 fps; across all powders the maximum-charge window runs from 1,752 fps to 3,031 fps. Accurate 3100 gives the best case fill at 100 %, and 92 of the 92 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 275.0 gr projectile in 0.375" calls for a 1:15.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, ADI AR 2225 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 | 275gr | SUS-TAC HP 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.