Load Specifications
Load data in caliber .378 Weath. Mag. with .375 | 300gr | Frontier PH PHL bullet and 83 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N560, Norma MRP and Accurate MAGPRO.
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% | 55,303 psi | 87% | 2749 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 56,985 psi | 89% | 2779 fps | 100% |
| Accurate High Country | <<locked>> | 94% | 56,753 psi | 89% | 2900 fps | 99.4% |
| Accurate MAGPRO | <<locked>> | 96% | 57,566 psi | 90% | 2904 fps | 98.7% |
| ADI AR 2208 | <<locked>> | 82% | 54,940 psi | 86% | 2690 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 57,667 psi | 90% | 2838 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 96% | 55,259 psi | 87% | 2844 fps | 99.1% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 46,253 psi | 72% | 2687 fps | 97.8% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 41,075 psi | 64% | 2654 fps | 99.3% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 54,259 psi | 85% | 2782 fps | 99.5% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 54,259 psi | 85% | 2782 fps | 99.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 56,217 psi | 88% | 2713 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 88% | 54,172 psi | 85% | 2782 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 55,332 psi | 87% | 2799 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 57,130 psi | 90% | 2828 fps | 99.8% |
| Alliant Reloder-22 | <<locked>> | 96% | 55,027 psi | 86% | 2838 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 98% | 56,014 psi | 88% | 2805 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 51,735 psi | 81% | 2815 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 56,449 psi | 88% | 2900 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 57,334 psi | 90% | 2805 fps | 96.9% |
| Bofors RP15ᴾ | <<locked>> | 100% | 57,667 psi | 90% | 2877 fps | 99.8% |
| Bofors RP3 | <<locked>> | 82% | 57,159 psi | 90% | 2730 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 47,718 psi | 75% | 2756 fps | 98.5% |
| Bofors RP5 | <<locked>> | 96% | 55,027 psi | 86% | 2838 fps | 99.7% |
| Bofors RP7 | <<locked>> | 86% | 56,173 psi | 88% | 2730 fps | 99.9% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 50,836 psi | 80% | 2769 fps | 99.1% |
| Hodgdon H380 | <<locked>> | 82% | 57,276 psi | 90% | 2753 fps | 100% |
| Hodgdon H414 | <<locked>> | 86% | 55,129 psi | 86% | 2785 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 54,505 psi | 85% | 2743 fps | 99.6% |
| Hodgdon H4831 | <<locked>> | 94% | 55,405 psi | 87% | 2785 fps | 98.5% |
| Hodgdon H4831 SC | <<locked>> | 94% | 54,244 psi | 85% | 2769 fps | 98.4% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 54,505 psi | 85% | 2707 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 50,691 psi | 79% | 2881 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 86% | 55,361 psi | 87% | 2822 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,985 psi | 58% | 1693 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 57,551 psi | 90% | 2769 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 86% | 57,624 psi | 90% | 2753 fps | 100% |
| IMR 4831 | <<locked>> | 90% | 57,334 psi | 90% | 2772 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 56,521 psi | 89% | 2766 fps | 98.8% |
| IMR 7828 SSC | <<locked>> | 98% | 56,666 psi | 89% | 2877 fps | 99.3% |
| Lovex S065 | <<locked>> | 86% | 54,723 psi | 86% | 2703 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 56,260 psi | 88% | 2749 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 52,707 psi | 83% | 2713 fps | 100% |
| Norma 204 | <<locked>> | 88% | 54,868 psi | 86% | 2772 fps | 99.5% |
| Norma 217ᴾ | <<locked>> | 100% | 36,564 psi | 57% | 2579 fps | 97.6% |
| Norma MRP | <<locked>> | 94% | 54,839 psi | 86% | 2861 fps | 100% |
| Norma URP | <<locked>> | 88% | 55,477 psi | 87% | 2766 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 57,551 psi | 90% | 2897 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 88% | 54,259 psi | 85% | 2772 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 55,521 psi | 87% | 2831 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,768 psi | 59% | 1736 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 56,985 psi | 89% | 2740 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 54,824 psi | 86% | 2785 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 56,869 psi | 89% | 2805 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 55,129 psi | 86% | 2835 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 50,966 psi | 80% | 2877 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 45,977 psi | 72% | 2762 fps | 96.7% |
| Rottweil R 903 | <<locked>> | 84% | 57,522 psi | 90% | 2726 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 55,506 psi | 87% | 2756 fps | 99% |
| Rottweil R 905 | <<locked>> | 94% | 56,594 psi | 89% | 2815 fps | 99.8% |
| Rottweil R 907 | <<locked>> | 86% | 56,173 psi | 88% | 2730 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 86% | 54,723 psi | 86% | 2703 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 56,260 psi | 88% | 2749 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 55,303 psi | 87% | 2736 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 57,551 psi | 90% | 2598 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 57,479 psi | 90% | 2707 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 56,144 psi | 88% | 2812 fps | 99.7% |
| Somchem S355 | <<locked>> | 84% | 57,188 psi | 90% | 2723 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 57,043 psi | 89% | 2749 fps | 98.7% |
| Somchem S365 | <<locked>> | 90% | 55,579 psi | 87% | 2766 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 57,116 psi | 90% | 2789 fps | 100% |
| Vihtavuori N150 | <<locked>> | 84% | 54,868 psi | 86% | 2648 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 57,319 psi | 90% | 2756 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 56,550 psi | 89% | 2769 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 88% | 56,405 psi | 88% | 2762 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 54,940 psi | 86% | 2785 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 54,824 psi | 86% | 2858 fps | 98.7% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 54,157 psi | 85% | 2835 fps | 98.8% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 47,239 psi | 74% | 2769 fps | 96.4% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 56,869 psi | 89% | 2717 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 55,274 psi | 87% | 2785 fps | 100% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 57,000 psi | 89% | 2940 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 57,159 psi | 90% | 2785 fps | 99.7% |
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% | 32,401 psi | 51% | 2339 fps | 97.4% |
| Accurate 4350 | <<locked>> | 80% | 43,598 psi | 68% | 2575 fps | 100% |
| Accurate High Country | <<locked>> | 82% | 37,449 psi | 59% | 2549 fps | 95.3% |
| Accurate MAGPRO | 102.4 gr | 88% | 43,511 psi | 68% | 2664 fps | 95.8% |
| ADI AR 2208 | <<locked>> | 80% | 51,721 psi | 81% | 2644 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 36,477 psi | 57% | 2457 fps | 95.9% |
| ADI AR 2213 | <<locked>> | 86% | 39,668 psi | 62% | 2556 fps | 95.6% |
| ADI AR 2217 | <<locked>> | 94% | 38,029 psi | 60% | 2516 fps | 95.2% |
| ADI AR 2225 | <<locked>> | 90% | 29,936 psi | 47% | 2369 fps | 95% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 36,782 psi | 58% | 2461 fps | 96.1% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 36,782 psi | 58% | 2461 fps | 96.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 52,750 psi | 83% | 2664 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 41,829 psi | 66% | 2582 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 48,080 psi | 75% | 2694 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 36,448 psi | 57% | 2454 fps | 96% |
| Alliant Reloder-22 | <<locked>> | 82% | 34,461 psi | 54% | 2451 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 31,125 psi | 49% | 2369 fps | 99.7% |
| Alliant Reloder-25 | <<locked>> | 80% | 27,209 psi | 43% | 2277 fps | 95.6% |
| Alliant Reloder-26 | <<locked>> | 80% | 33,562 psi | 53% | 2493 fps | 99% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 50,749 psi | 80% | 2697 fps | 95.4% |
| Bofors RP15 | <<locked>> | 84% | 34,360 psi | 54% | 2448 fps | 95.3% |
| Bofors RP3 | <<locked>> | 80% | 53,592 psi | 84% | 2680 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 36,463 psi | 57% | 2533 fps | 95.4% |
| Bofors RP5 | <<locked>> | 82% | 34,461 psi | 54% | 2451 fps | 95.5% |
| Bofors RP7 | <<locked>> | 80% | 46,688 psi | 73% | 2579 fps | 99.2% |
| Hodgdon H1000 | <<locked>> | 90% | 36,419 psi | 57% | 2484 fps | 95.3% |
| Hodgdon H380 | <<locked>> | 80% | 53,693 psi | 84% | 2700 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 45,281 psi | 71% | 2625 fps | 99.4% |
| Hodgdon H4350 | <<locked>> | 80% | 47,863 psi | 75% | 2635 fps | 98.9% |
| Hodgdon H4831 | <<locked>> | 86% | 42,351 psi | 66% | 2562 fps | 95.8% |
| Hodgdon H4831 SC | <<locked>> | 86% | 41,582 psi | 65% | 2546 fps | 95.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 39,421 psi | 62% | 2470 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 88% | 34,345 psi | 54% | 2523 fps | 95.9% |
| Hodgdon Superformance | <<locked>> | 80% | 44,425 psi | 70% | 2648 fps | 99.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,673 psi | 43% | 1512 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 42,119 psi | 66% | 2516 fps | 98.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 47,921 psi | 75% | 2602 fps | 99.5% |
| IMR 4831 | <<locked>> | 80% | 41,524 psi | 65% | 2526 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 41,524 psi | 65% | 2510 fps | 95.7% |
| IMR 7828 SSC | <<locked>> | 86% | 38,087 psi | 60% | 2536 fps | 95.2% |
| Lovex S065 | <<locked>> | 80% | 45,585 psi | 71% | 2556 fps | 99.8% |
| Lovex S070 | <<locked>> | 80% | 43,830 psi | 69% | 2546 fps | 99.2% |
| Lovex S071 | <<locked>> | 80% | 27,920 psi | 44% | 2224 fps | 95.5% |
| Norma 204 | <<locked>> | 80% | 41,843 psi | 66% | 2549 fps | 97.4% |
| Norma 217 | <<locked>> | 96% | 32,169 psi | 50% | 2467 fps | 95.8% |
| Norma MRP | 91.4 gr | 80% | 33,649 psi | 53% | 2461 fps | 96.7% |
| Norma URP | <<locked>> | 80% | 42,815 psi | 67% | 2566 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 37,550 psi | 59% | 2536 fps | 95.4% |
| Ramshot Hunter | <<locked>> | 80% | 41,597 psi | 65% | 2562 fps | 99.4% |
| Ramshot Magnum | <<locked>> | 86% | 33,446 psi | 52% | 2425 fps | 95.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,311 psi | 44% | 1552 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 53,403 psi | 84% | 2687 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 51,024 psi | 80% | 2733 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 43,410 psi | 68% | 2595 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 41,669 psi | 65% | 2612 fps | 99.9% |
| ReloadSwiss RS 76 | <<locked>> | 86% | 31,183 psi | 49% | 2434 fps | 95.6% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 42,685 psi | 67% | 2697 fps | 95.7% |
| Rottweil R 903 | <<locked>> | 80% | 50,502 psi | 79% | 2631 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 37,826 psi | 59% | 2438 fps | 95.2% |
| Rottweil R 905 | <<locked>> | 80% | 35,650 psi | 56% | 2438 fps | 96% |
| Rottweil R 907 | <<locked>> | 80% | 46,688 psi | 73% | 2579 fps | 99.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 45,585 psi | 71% | 2556 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 80% | 43,830 psi | 69% | 2546 fps | 99.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 51,706 psi | 81% | 2687 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 50,908 psi | 80% | 2516 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 44,599 psi | 70% | 2507 fps | 99.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 35,331 psi | 55% | 2434 fps | 95.8% |
| Somchem S355 | <<locked>> | 80% | 50,531 psi | 79% | 2628 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 41,017 psi | 64% | 2480 fps | 95.3% |
| Somchem S365 | <<locked>> | 80% | 39,682 psi | 62% | 2523 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 36,260 psi | 57% | 2425 fps | 97% |
| Vihtavuori N150 | <<locked>> | 80% | 48,254 psi | 76% | 2556 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 44,309 psi | 69% | 2559 fps | 100% |
| Vihtavuori N165 | <<locked>> | 82% | 33,533 psi | 53% | 2359 fps | 95.7% |
| Vihtavuori N550 | <<locked>> | 80% | 43,685 psi | 68% | 2566 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 34,896 psi | 55% | 2438 fps | 99.6% |
| Vihtavuori N560 | 96 gr | 84% | 38,986 psi | 61% | 2566 fps | 95% |
| Vihtavuori N565 | <<locked>> | 90% | 38,682 psi | 61% | 2556 fps | 95.3% |
| Vihtavuori N568 | <<locked>> | 98% | 44,063 psi | 69% | 2710 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 43,163 psi | 68% | 2523 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 45,411 psi | 71% | 2628 fps | 99.4% |
| Winchester StaBALL HD | <<locked>> | 80% | 27,499 psi | 43% | 2379 fps | 99.7% |
| Winchester Supreme 780 | <<locked>> | 82% | 35,331 psi | 55% | 2405 fps | 95.6% |
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 83 powders for .378 Weath. Mag. loaded with the .375 | 300gr | Frontier PH PHL. Winchester StaBALL HD delivers the highest muzzle velocity at 2,940 fps; across all powders the maximum-charge window runs from 1,693 fps to 2,940 fps. ADI AR 2217 gives the best case fill at 100 %, and 83 of the 83 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 300.0 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-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. Vihtavuori N560, Norma MRP, Accurate MAGPRO rank at the top here: for .378 Weath. Mag. with the .375 | 300gr | Frontier PH PHL 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.