Load Specifications
Load data in caliber .378 Weath. Mag. with .375 | 270gr | Barnes X S bullet and 80 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 MAGPRO 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>> | 96% | 54,273 psi | 85% | 2854 fps | 99.9% |
| Accurate 4350 | <<locked>> | 88% | 55,999 psi | 88% | 2890 fps | 100% |
| Accurate MAGPRO | <<locked>> | 96% | 55,448 psi | 87% | 2989 fps | 97.3% |
| ADI AR 2208 | <<locked>> | 84% | 57,130 psi | 90% | 2844 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 55,767 psi | 87% | 2930 fps | 99% |
| ADI AR 2213 | <<locked>> | 98% | 57,072 psi | 89% | 2986 fps | 98.3% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 45,179 psi | 71% | 2762 fps | 95.9% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 40,466 psi | 63% | 2733 fps | 97.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 55,187 psi | 86% | 2822 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 55,680 psi | 87% | 2936 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 57,058 psi | 89% | 2956 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 55,288 psi | 87% | 2920 fps | 99% |
| Alliant Reloder-22 | <<locked>> | 98% | 56,768 psi | 89% | 2989 fps | 99.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 57,421 psi | 90% | 2959 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 50,038 psi | 78% | 2910 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 54,041 psi | 85% | 3002 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 55,637 psi | 87% | 2969 fps | 99.1% |
| Bofors RP3 | <<locked>> | 82% | 56,579 psi | 89% | 2844 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 46,253 psi | 72% | 2841 fps | 97% |
| Bofors RP5 | <<locked>> | 98% | 56,768 psi | 89% | 2989 fps | 99.3% |
| Bofors RP7 | <<locked>> | 86% | 55,245 psi | 87% | 2831 fps | 99.4% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 49,371 psi | 77% | 2848 fps | 97.7% |
| Hodgdon H380 | <<locked>> | 82% | 56,289 psi | 88% | 2861 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 57,145 psi | 90% | 2936 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 86% | 56,492 psi | 89% | 2890 fps | 99.2% |
| Hodgdon H4831 | <<locked>> | 96% | 57,087 psi | 89% | 2923 fps | 97.7% |
| Hodgdon H4831 SC | <<locked>> | 96% | 56,115 psi | 88% | 2910 fps | 97.6% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 56,405 psi | 88% | 2858 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 49,124 psi | 77% | 2963 fps | 99% |
| Hodgdon Superformance | <<locked>> | 88% | 57,174 psi | 90% | 2972 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,115 psi | 58% | 1778 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 56,797 psi | 89% | 2828 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 56,130 psi | 88% | 2867 fps | 99.6% |
| IMR 4451 Enduron | <<locked>> | 86% | 56,289 psi | 88% | 2851 fps | 99.7% |
| IMR 4831 | <<locked>> | 90% | 56,130 psi | 88% | 2881 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 55,114 psi | 86% | 2858 fps | 97.6% |
| IMR 7828 SSC | <<locked>> | 98% | 54,824 psi | 86% | 2963 fps | 98.1% |
| Lovex S062 | <<locked>> | 82% | 57,609 psi | 90% | 2825 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 57,087 psi | 89% | 2854 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 55,361 psi | 87% | 2851 fps | 99.8% |
| Lovex S071ᴾ | <<locked>> | 100% | 51,982 psi | 81% | 2818 fps | 99.8% |
| Norma 204 | <<locked>> | 90% | 56,826 psi | 89% | 2920 fps | 99% |
| Norma 217ᴾ | <<locked>> | 100% | 36,303 psi | 57% | 2664 fps | 95.9% |
| Norma MRP | <<locked>> | 96% | 56,507 psi | 89% | 3015 fps | 99.9% |
| Norma URP | <<locked>> | 90% | 57,464 psi | 90% | 2920 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 55,201 psi | 87% | 2979 fps | 98.5% |
| Ramshot Hunter | <<locked>> | 90% | 56,159 psi | 88% | 2927 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 53,374 psi | 84% | 2917 fps | 99.4% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,913 psi | 59% | 1821 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 55,869 psi | 88% | 2844 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 56,463 psi | 88% | 2943 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 55,463 psi | 87% | 2910 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 56,956 psi | 89% | 2989 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 49,356 psi | 77% | 2959 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 84% | 56,724 psi | 89% | 2844 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 57,363 psi | 90% | 2897 fps | 98.4% |
| Rottweil R 905 | <<locked>> | 94% | 54,998 psi | 86% | 2910 fps | 99.1% |
| Rottweil R 907 | <<locked>> | 86% | 55,245 psi | 87% | 2831 fps | 99.4% |
| Shooters World Long Rifle | <<locked>> | 88% | 57,087 psi | 89% | 2854 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 57,609 psi | 90% | 2825 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 55,361 psi | 87% | 2851 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 57,377 psi | 90% | 2894 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 56,391 psi | 88% | 2710 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 56,594 psi | 89% | 2808 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 54,534 psi | 85% | 2907 fps | 99% |
| Somchem S355 | <<locked>> | 84% | 56,304 psi | 88% | 2835 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 55,579 psi | 87% | 2838 fps | 97.4% |
| Somchem S365 | <<locked>> | 92% | 57,363 psi | 90% | 2920 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 55,825 psi | 87% | 2887 fps | 99.5% |
| Vihtavuori N150 | <<locked>> | 86% | 57,217 psi | 90% | 2802 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 55,898 psi | 88% | 2861 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 54,839 psi | 86% | 2861 fps | 99.2% |
| Vihtavuori N550 | <<locked>> | 88% | 55,201 psi | 87% | 2867 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 57,058 psi | 89% | 2943 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 56,492 psi | 89% | 3005 fps | 98% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 52,518 psi | 82% | 2923 fps | 97.5% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 55,013 psi | 86% | 2822 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 57,290 psi | 90% | 2940 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 53,519 psi | 84% | 3041 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 55,288 psi | 87% | 2877 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 3100 | <<locked>> | 80% | 33,040 psi | 52% | 2444 fps | 96.3% |
| Accurate 4350 | <<locked>> | 80% | 43,497 psi | 68% | 2684 fps | 99.8% |
| Accurate MAGPRO | 106.5 gr | 92% | 48,617 psi | 76% | 2871 fps | 95.7% |
| ADI AR 2208 | <<locked>> | 80% | 50,705 psi | 79% | 2746 fps | 100% |
| ADI AR 2209 | <<locked>> | 82% | 38,522 psi | 60% | 2602 fps | 95.1% |
| ADI AR 2213 | <<locked>> | 90% | 44,353 psi | 70% | 2756 fps | 95.5% |
| ADI AR 2217 | <<locked>> | 98% | 42,424 psi | 66% | 2703 fps | 95% |
| ADI AR 2225 | <<locked>> | 94% | 33,953 psi | 53% | 2562 fps | 95.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 52,040 psi | 82% | 2776 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 41,060 psi | 64% | 2680 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 46,775 psi | 73% | 2799 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 38,464 psi | 60% | 2598 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 86% | 38,972 psi | 61% | 2657 fps | 95.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 31,285 psi | 49% | 2467 fps | 99% |
| Alliant Reloder-25 | <<locked>> | 82% | 29,414 psi | 46% | 2425 fps | 95.1% |
| Alliant Reloder-26 | 93.6 gr | 80% | 33,605 psi | 53% | 2592 fps | 98% |
| Bofors RP15 | <<locked>> | 88% | 38,653 psi | 61% | 2648 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 53,156 psi | 83% | 2795 fps | 100% |
| Bofors RP30 | <<locked>> | 96% | 40,814 psi | 64% | 2730 fps | 95.4% |
| Bofors RP5 | <<locked>> | 86% | 38,972 psi | 61% | 2657 fps | 95.7% |
| Bofors RP7 | <<locked>> | 80% | 46,253 psi | 72% | 2677 fps | 98.3% |
| Hodgdon H1000 | <<locked>> | 94% | 40,886 psi | 64% | 2674 fps | 95.2% |
| Hodgdon H380 | <<locked>> | 80% | 52,939 psi | 83% | 2808 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 44,570 psi | 70% | 2720 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 80% | 47,065 psi | 74% | 2730 fps | 97.9% |
| Hodgdon H4831 | <<locked>> | 90% | 47,253 psi | 74% | 2759 fps | 95.7% |
| Hodgdon H4831 SC | <<locked>> | 90% | 46,398 psi | 73% | 2743 fps | 95.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 39,059 psi | 61% | 2575 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 92% | 38,508 psi | 60% | 2720 fps | 95.9% |
| Hodgdon Superformance | <<locked>> | 80% | 43,424 psi | 68% | 2740 fps | 98% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,934 psi | 44% | 1591 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 53,374 psi | 84% | 2779 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 41,582 psi | 65% | 2608 fps | 97.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 47,224 psi | 74% | 2700 fps | 98.8% |
| IMR 4831 | <<locked>> | 80% | 41,263 psi | 65% | 2628 fps | 99.6% |
| IMR 4955 Enduron | <<locked>> | 88% | 46,093 psi | 72% | 2700 fps | 95.6% |
| IMR 7828 SSC | <<locked>> | 90% | 42,583 psi | 67% | 2733 fps | 95.1% |
| Lovex S062 | <<locked>> | 80% | 54,201 psi | 85% | 2776 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 45,339 psi | 71% | 2657 fps | 99.3% |
| Lovex S070 | <<locked>> | 80% | 43,758 psi | 69% | 2648 fps | 98.4% |
| Lovex S071 | <<locked>> | 82% | 30,618 psi | 48% | 2382 fps | 95.3% |
| Norma 204 | <<locked>> | 80% | 41,234 psi | 65% | 2641 fps | 95.9% |
| Norma 217 | <<locked>> | 98% | 34,272 psi | 54% | 2612 fps | 95% |
| Norma MRP | 90.9 gr | 80% | 33,663 psi | 53% | 2556 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 42,424 psi | 66% | 2667 fps | 99.6% |
| Ramshot Grand | <<locked>> | 90% | 42,366 psi | 66% | 2740 fps | 95.4% |
| Ramshot Hunter | <<locked>> | 80% | 41,031 psi | 64% | 2657 fps | 98.5% |
| Ramshot Magnum | <<locked>> | 88% | 35,679 psi | 56% | 2569 fps | 95.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,500 psi | 45% | 1627 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 52,475 psi | 82% | 2789 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 49,429 psi | 77% | 2841 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 42,844 psi | 67% | 2697 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 40,959 psi | 64% | 2707 fps | 99.3% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 35,592 psi | 56% | 2641 fps | 95.9% |
| Rottweil R 903 | <<locked>> | 80% | 50,285 psi | 79% | 2746 fps | 100% |
| Rottweil R 904 | <<locked>> | 84% | 42,453 psi | 67% | 2635 fps | 95.2% |
| Rottweil R 905 | <<locked>> | 82% | 37,797 psi | 59% | 2585 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 46,253 psi | 72% | 2677 fps | 98.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 45,339 psi | 71% | 2657 fps | 99.3% |
| Shooters World Precision | <<locked>> | 80% | 54,201 psi | 85% | 2776 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 43,758 psi | 69% | 2648 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 50,633 psi | 79% | 2792 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 50,227 psi | 79% | 2625 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 44,411 psi | 70% | 2605 fps | 98.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 37,449 psi | 59% | 2582 fps | 95.1% |
| Somchem S355 | <<locked>> | 80% | 50,024 psi | 78% | 2740 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 46,006 psi | 72% | 2674 fps | 95.3% |
| Somchem S365 | <<locked>> | 80% | 39,088 psi | 61% | 2631 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 36,419 psi | 57% | 2523 fps | 95.7% |
| Vihtavuori N150 | <<locked>> | 80% | 47,819 psi | 75% | 2664 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 43,700 psi | 68% | 2657 fps | 99.7% |
| Vihtavuori N165 | <<locked>> | 84% | 35,636 psi | 56% | 2500 fps | 95% |
| Vihtavuori N550 | <<locked>> | 80% | 43,250 psi | 68% | 2667 fps | 99.6% |
| Vihtavuori N555 | <<locked>> | 80% | 35,041 psi | 55% | 2546 fps | 99% |
| Vihtavuori N560 | <<locked>> | 88% | 43,685 psi | 68% | 2769 fps | 95% |
| Vihtavuori N565 | <<locked>> | 94% | 43,439 psi | 68% | 2756 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 42,438 psi | 67% | 2621 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 44,686 psi | 70% | 2723 fps | 98.5% |
| Winchester StaBALL HD | <<locked>> | 80% | 28,079 psi | 44% | 2477 fps | 99% |
| Winchester Supreme 780 | <<locked>> | 86% | 40,001 psi | 63% | 2605 fps | 95.8% |
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 80 powders for .378 Weath. Mag. loaded with the .375 | 270gr | Barnes X S. Winchester StaBALL HD delivers the highest muzzle velocity at 3,041 fps; across all powders the maximum-charge window runs from 1,778 fps to 3,041 fps. ADI AR 2217 gives the best case fill at 100 %, and 80 of the 80 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 270.0 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-23 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 MAGPRO, Norma MRP rank at the top here: for .378 Weath. Mag. with the .375 | 270gr | Barnes X S 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.