Load Specifications
Load data in caliber .378 Weath. Mag. with .375 | 270gr | Brenneke TOG bullet and 87 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Norma MRP, Vihtavuori N560 and Alliant Reloder-26.
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>> | 82% | 56,376 psi | 88% | 2841 fps | 99.5% |
| Accurate 3100 | <<locked>> | 98% | 55,550 psi | 87% | 2900 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 56,246 psi | 88% | 2818 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 57,479 psi | 90% | 2940 fps | 100% |
| Accurate MAGPRO | <<locked>> | 96% | 53,838 psi | 84% | 2989 fps | 97.2% |
| ADI AR 2208 | <<locked>> | 84% | 55,840 psi | 88% | 2854 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 54,447 psi | 85% | 2936 fps | 99% |
| ADI AR 2213 | <<locked>> | 98% | 55,840 psi | 88% | 2992 fps | 98.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 38,479 psi | 60% | 2717 fps | 97.6% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 54,737 psi | 86% | 2933 fps | 99.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 56,884 psi | 89% | 2874 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 57,029 psi | 89% | 2897 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 54,389 psi | 85% | 2943 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 55,651 psi | 87% | 2959 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 57,493 psi | 90% | 2979 fps | 99.4% |
| Alliant Reloder-22 | <<locked>> | 98% | 55,259 psi | 87% | 2989 fps | 99.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 55,999 psi | 88% | 2963 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 48,414 psi | 76% | 2907 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 56,376 psi | 88% | 3058 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 54,099 psi | 85% | 2969 fps | 99.1% |
| Bofors RP3 | <<locked>> | 82% | 54,259 psi | 85% | 2841 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 44,295 psi | 69% | 2828 fps | 96.7% |
| Bofors RP5 | <<locked>> | 98% | 55,259 psi | 87% | 2989 fps | 99.3% |
| Bofors RP7 | <<locked>> | 88% | 56,956 psi | 89% | 2887 fps | 99.7% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 47,877 psi | 75% | 2848 fps | 97.7% |
| Hodgdon H380 | <<locked>> | 82% | 54,418 psi | 85% | 2861 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 55,622 psi | 87% | 2940 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 86% | 55,027 psi | 86% | 2897 fps | 99.2% |
| Hodgdon H4831 | <<locked>> | 96% | 55,898 psi | 88% | 2933 fps | 97.8% |
| Hodgdon H4831 SC | <<locked>> | 96% | 54,737 psi | 86% | 2913 fps | 97.6% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 54,868 psi | 86% | 2864 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 47,398 psi | 74% | 2956 fps | 98.9% |
| Hodgdon Superformance | <<locked>> | 88% | 55,956 psi | 88% | 2979 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,753 psi | 58% | 1791 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 55,245 psi | 87% | 2835 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 57,624 psi | 90% | 2874 fps | 99.9% |
| IMR 4350 | <<locked>> | 90% | 54,650 psi | 86% | 2871 fps | 99.5% |
| IMR 4451 Enduron | <<locked>> | 86% | 54,969 psi | 86% | 2858 fps | 99.7% |
| IMR 4831 | <<locked>> | 90% | 54,085 psi | 85% | 2877 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 57,174 psi | 90% | 2917 fps | 98.1% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 57,072 psi | 89% | 3025 fps | 98.7% |
| Lovex S062 | <<locked>> | 82% | 55,608 psi | 87% | 2825 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 55,376 psi | 87% | 2858 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 56,811 psi | 89% | 2904 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 49,429 psi | 77% | 2805 fps | 99.7% |
| Norma 203B | <<locked>> | 82% | 56,318 psi | 88% | 2884 fps | 100% |
| Norma 204 | <<locked>> | 90% | 55,492 psi | 87% | 2927 fps | 99% |
| Norma MRP | <<locked>> | 96% | 54,853 psi | 86% | 3012 fps | 99.8% |
| Norma URP | <<locked>> | 90% | 55,927 psi | 88% | 2923 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 57,232 psi | 90% | 2910 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 53,824 psi | 84% | 2986 fps | 98.5% |
| Ramshot Hunter | <<locked>> | 90% | 54,679 psi | 86% | 2927 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 51,895 psi | 81% | 2920 fps | 99.4% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,449 psi | 59% | 1834 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 54,215 psi | 85% | 2844 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 55,172 psi | 86% | 2949 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 57,305 psi | 90% | 2963 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 55,608 psi | 87% | 2995 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 47,645 psi | 75% | 2953 fps | 99.6% |
| Rottweil R 902 | <<locked>> | 82% | 57,479 psi | 90% | 2835 fps | 100% |
| Rottweil R 903 | <<locked>> | 84% | 54,447 psi | 85% | 2838 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 56,072 psi | 88% | 2907 fps | 98.4% |
| Rottweil R 905 | <<locked>> | 96% | 56,898 psi | 89% | 2966 fps | 99.4% |
| Rottweil R 907 | <<locked>> | 88% | 56,956 psi | 89% | 2887 fps | 99.7% |
| Shooters World Long Rifle | <<locked>> | 88% | 55,376 psi | 87% | 2858 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 55,608 psi | 87% | 2825 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 56,811 psi | 89% | 2904 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 55,883 psi | 88% | 2897 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 54,926 psi | 86% | 2717 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 54,897 psi | 86% | 2812 fps | 99.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 56,420 psi | 88% | 2963 fps | 99.3% |
| Somchem S355 | <<locked>> | 84% | 54,317 psi | 85% | 2835 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 54,114 psi | 85% | 2841 fps | 97.4% |
| Somchem S365 | <<locked>> | 92% | 55,709 psi | 87% | 2923 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 57,551 psi | 90% | 2940 fps | 99.7% |
| Vihtavuori N150 | <<locked>> | 86% | 55,477 psi | 87% | 2805 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 54,244 psi | 85% | 2864 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 56,826 psi | 89% | 2917 fps | 99.6% |
| Vihtavuori N540 | <<locked>> | 82% | 56,231 psi | 88% | 2805 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 57,014 psi | 89% | 2920 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 54,882 psi | 86% | 2936 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 54,969 psi | 86% | 3005 fps | 98% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 50,676 psi | 79% | 2917 fps | 97.4% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 57,580 psi | 90% | 2874 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 55,753 psi | 87% | 2940 fps | 99.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 52,185 psi | 82% | 3041 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 57,711 psi | 90% | 2936 fps | 99.3% |
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% | 52,866 psi | 83% | 2785 fps | 99.2% |
| Accurate 3100 | <<locked>> | 80% | 30,168 psi | 47% | 2405 fps | 95.3% |
| Accurate 4064 | <<locked>> | 80% | 52,852 psi | 83% | 2772 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 40,814 psi | 64% | 2664 fps | 99.6% |
| Accurate MAGPRO | <<locked>> | 92% | 46,833 psi | 73% | 2864 fps | 95.5% |
| ADI AR 2208 | <<locked>> | 80% | 49,342 psi | 77% | 2753 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 39,218 psi | 61% | 2644 fps | 95.6% |
| ADI AR 2213 | <<locked>> | 90% | 42,714 psi | 67% | 2749 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 96% | 33,924 psi | 53% | 2595 fps | 95.6% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 39,436 psi | 62% | 2648 fps | 95.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 50,227 psi | 79% | 2776 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 53,432 psi | 84% | 2844 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 39,407 psi | 62% | 2674 fps | 99.7% |
| Alliant Reloder-17 | <<locked>> | 80% | 44,991 psi | 71% | 2792 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 39,044 psi | 61% | 2641 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 86% | 36,912 psi | 58% | 2635 fps | 95.1% |
| Alliant Reloder-23 | <<locked>> | 80% | 29,138 psi | 46% | 2438 fps | 98.5% |
| Alliant Reloder-25 | <<locked>> | 84% | 29,037 psi | 46% | 2448 fps | 95.2% |
| Alliant Reloder-26 | 96.7 gr | 80% | 31,299 psi | 49% | 2556 fps | 97.3% |
| Bofors RP15 | <<locked>> | 90% | 39,088 psi | 61% | 2684 fps | 95.8% |
| Bofors RP3 | <<locked>> | 80% | 50,792 psi | 80% | 2789 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 41,510 psi | 65% | 2772 fps | 95.9% |
| Bofors RP5 | <<locked>> | 86% | 36,912 psi | 58% | 2635 fps | 95.1% |
| Bofors RP7 | <<locked>> | 80% | 44,396 psi | 70% | 2671 fps | 98.1% |
| Hodgdon H1000 | <<locked>> | 96% | 41,858 psi | 66% | 2726 fps | 95.9% |
| Hodgdon H380 | <<locked>> | 80% | 51,010 psi | 80% | 2808 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 42,670 psi | 67% | 2713 fps | 98.3% |
| Hodgdon H4350 | <<locked>> | 80% | 45,426 psi | 71% | 2726 fps | 97.7% |
| Hodgdon H4831 | <<locked>> | 90% | 45,614 psi | 71% | 2756 fps | 95.5% |
| Hodgdon H4831 SC | <<locked>> | 90% | 44,817 psi | 70% | 2740 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 37,043 psi | 58% | 2562 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 92% | 36,593 psi | 57% | 2700 fps | 95.4% |
| Hodgdon Superformance | <<locked>> | 80% | 41,611 psi | 65% | 2726 fps | 97.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,470 psi | 43% | 1601 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 51,938 psi | 81% | 2782 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 54,056 psi | 85% | 2818 fps | 99.7% |
| IMR 4350 | <<locked>> | 80% | 40,001 psi | 63% | 2605 fps | 97.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 45,759 psi | 72% | 2700 fps | 98.7% |
| IMR 4831 | <<locked>> | 80% | 39,160 psi | 61% | 2615 fps | 99.4% |
| IMR 4955 Enduron | <<locked>> | 88% | 44,614 psi | 70% | 2700 fps | 95.4% |
| IMR 7828 SSC | <<locked>> | 92% | 43,700 psi | 68% | 2785 fps | 95.8% |
| Lovex S062 | <<locked>> | 80% | 52,301 psi | 82% | 2776 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 43,308 psi | 68% | 2651 fps | 99.2% |
| Lovex S070 | <<locked>> | 80% | 41,640 psi | 65% | 2638 fps | 98.2% |
| Lovex S071 | <<locked>> | 84% | 29,617 psi | 46% | 2388 fps | 95.1% |
| Norma 203B | <<locked>> | 80% | 52,794 psi | 83% | 2831 fps | 100% |
| Norma 204 | <<locked>> | 80% | 39,552 psi | 62% | 2631 fps | 95.6% |
| Norma MRP | 96.2 gr | 82% | 33,692 psi | 53% | 2585 fps | 95.4% |
| Norma URP | <<locked>> | 80% | 40,422 psi | 63% | 2657 fps | 99.5% |
| Ramshot Big Game | <<locked>> | 80% | 53,505 psi | 84% | 2858 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 40,480 psi | 63% | 2726 fps | 95.1% |
| Ramshot Hunter | <<locked>> | 80% | 39,233 psi | 61% | 2648 fps | 98.2% |
| Ramshot Magnum | <<locked>> | 90% | 36,027 psi | 56% | 2605 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,036 psi | 44% | 1640 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 50,879 psi | 80% | 2792 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 47,761 psi | 75% | 2838 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 40,611 psi | 64% | 2684 fps | 99.4% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 39,160 psi | 61% | 2694 fps | 99.1% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 33,504 psi | 53% | 2615 fps | 95.2% |
| Rottweil R 902 | <<locked>> | 80% | 54,041 psi | 85% | 2785 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 47,921 psi | 75% | 2740 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 43,439 psi | 68% | 2684 fps | 95.7% |
| Rottweil R 905 | <<locked>> | 84% | 38,261 psi | 60% | 2625 fps | 95.7% |
| Rottweil R 907 | <<locked>> | 80% | 44,396 psi | 70% | 2671 fps | 98.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 43,308 psi | 68% | 2651 fps | 99.2% |
| Shooters World Precision | <<locked>> | 80% | 52,301 psi | 82% | 2776 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 41,640 psi | 65% | 2638 fps | 98.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 49,066 psi | 77% | 2795 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 48,689 psi | 76% | 2628 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 42,322 psi | 66% | 2595 fps | 98.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 37,913 psi | 59% | 2618 fps | 95.5% |
| Somchem S355 | <<locked>> | 80% | 47,964 psi | 75% | 2733 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 44,396 psi | 70% | 2674 fps | 95.1% |
| Somchem S365 | <<locked>> | 80% | 37,043 psi | 58% | 2615 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 34,098 psi | 53% | 2497 fps | 95.1% |
| Vihtavuori N150 | <<locked>> | 80% | 45,876 psi | 72% | 2661 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 41,742 psi | 65% | 2651 fps | 99.6% |
| Vihtavuori N165 | <<locked>> | 86% | 35,897 psi | 56% | 2536 fps | 95.3% |
| Vihtavuori N540 | <<locked>> | 80% | 52,808 psi | 83% | 2756 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 41,220 psi | 65% | 2654 fps | 99.5% |
| Vihtavuori N555 | <<locked>> | 80% | 32,474 psi | 51% | 2513 fps | 98.4% |
| Vihtavuori N560 | 105.6 gr | 90% | 44,817 psi | 70% | 2822 fps | 95.7% |
| Vihtavuori N565 | <<locked>> | 96% | 44,208 psi | 69% | 2799 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 40,799 psi | 64% | 2618 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 42,801 psi | 67% | 2713 fps | 98.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,802 psi | 40% | 2428 fps | 98.1% |
| Winchester Supreme 780 | <<locked>> | 86% | 38,087 psi | 60% | 2592 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 87 powders for .378 Weath. Mag. loaded with the .375 | 270gr | Brenneke TOG. Alliant Reloder-26 delivers the highest muzzle velocity at 3,058 fps; across all powders the maximum-charge window runs from 1,791 fps to 3,058 fps. ADI AR 2225 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 58–90 %, leaving at least 10 % headroom. The 270.0 gr projectile in 0.375" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. ADI AR 2225, Alliant Reloder-23, 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. Norma MRP, Vihtavuori N560, Alliant Reloder-26 rank at the top here: for .378 Weath. Mag. with the .375 | 270gr | Brenneke TOG 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.