Load Specifications
Load data in caliber .378 Weath. Mag. with .375 | 350gr | Woodleigh RN SN bullet and 73 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, Accurate MAGPRO and ReloadSwiss RS 76.
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>> | 92% | 55,143 psi | 86% | 2502 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 56,391 psi | 88% | 2562 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 54,389 psi | 85% | 2654 fps | 99% |
| ADI AR 2209 | <<locked>> | 90% | 57,029 psi | 89% | 2580 fps | 100% |
| ADI AR 2213 | <<locked>> | 92% | 54,621 psi | 86% | 2588 fps | 99.6% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,751 psi | 84% | 2561 fps | 99.6% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 47,384 psi | 74% | 2530 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 57,145 psi | 90% | 2625 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 86% | 57,319 psi | 90% | 2565 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 56,478 psi | 89% | 2569 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 92% | 54,868 psi | 86% | 2585 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 94% | 56,362 psi | 88% | 2551 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 56,826 psi | 89% | 2613 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 56,753 psi | 89% | 2636 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 49,226 psi | 77% | 2576 fps | 96.4% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 56,014 psi | 88% | 2558 fps | 97.9% |
| Bofors RP15 | <<locked>> | 96% | 57,711 psi | 90% | 2671 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 56,202 psi | 88% | 2622 fps | 99.8% |
| Bofors RP5 | <<locked>> | 92% | 54,868 psi | 86% | 2635 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 54,752 psi | 86% | 2470 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 54,056 psi | 85% | 2631 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 55,390 psi | 87% | 2559 fps | 100% |
| Hodgdon H4831 | <<locked>> | 94% | 54,070 psi | 85% | 2526 fps | 99.1% |
| Hodgdon H4831 SC | <<locked>> | 92% | 57,072 psi | 89% | 2568 fps | 99.4% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 57,508 psi | 90% | 2494 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 54,462 psi | 85% | 2740 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 54,331 psi | 85% | 2556 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,811 psi | 59% | 1551 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 57,522 psi | 90% | 2485 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 56,318 psi | 88% | 2552 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 55,985 psi | 88% | 2533 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 54,592 psi | 86% | 2485 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 55,550 psi | 87% | 2562 fps | 99.6% |
| IMR 7828 SSC | <<locked>> | 92% | 56,768 psi | 89% | 2627 fps | 99.8% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 43,656 psi | 68% | 2449 fps | 98.2% |
| Lovex S065 | <<locked>> | 84% | 56,826 psi | 89% | 2486 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 55,143 psi | 86% | 2488 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 57,464 psi | 90% | 2517 fps | 100% |
| Norma 204 | <<locked>> | 86% | 57,406 psi | 90% | 2564 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 43,468 psi | 68% | 2474 fps | 99.7% |
| Norma MRP | <<locked>> | 90% | 54,737 psi | 86% | 2602 fps | 100% |
| Norma URP | <<locked>> | 84% | 54,737 psi | 86% | 2502 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 56,536 psi | 89% | 2634 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 86% | 57,072 psi | 89% | 2559 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 57,653 psi | 90% | 2610 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,421 psi | 62% | 1588 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 56,246 psi | 88% | 2541 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 54,534 psi | 85% | 2567 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 55,637 psi | 87% | 2684 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 53,954 psi | 85% | 2647 fps | 99.1% |
| Rottweil R 904 | <<locked>> | 88% | 54,491 psi | 85% | 2503 fps | 99.5% |
| Rottweil R 905 | <<locked>> | 90% | 56,014 psi | 88% | 2560 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 54,752 psi | 86% | 2470 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 56,826 psi | 89% | 2486 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 55,143 psi | 86% | 2533 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 55,941 psi | 88% | 2448 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 55,579 psi | 87% | 2602 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 55,651 psi | 87% | 2499 fps | 99.2% |
| Somchem S365 | <<locked>> | 86% | 55,317 psi | 87% | 2504 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 56,434 psi | 88% | 2534 fps | 100% |
| Unknown powder | <<locked>> | 82% | 54,781 psi | 86% | 2501 fps | 100% |
| Vihtavuori N150 | <<locked>> | 84% | 54,317 psi | 85% | 2401 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 54,940 psi | 86% | 2473 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 54,215 psi | 85% | 2497 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 55,521 psi | 87% | 2514 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 55,114 psi | 86% | 2530 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 55,187 psi | 86% | 2614 fps | 99.4% |
| Vihtavuori N565 | <<locked>> | 96% | 54,447 psi | 85% | 2590 fps | 99.5% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 55,869 psi | 88% | 2646 fps | 98.9% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 52,750 psi | 83% | 2644 fps | 96.9% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 55,550 psi | 87% | 2456 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 54,563 psi | 86% | 2631 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 53,882 psi | 84% | 2501 fps | 99.9% |
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% | 36,999 psi | 58% | 2218 fps | 99.3% |
| Accurate 4350 | <<locked>> | 80% | 49,284 psi | 77% | 2467 fps | 100% |
| Accurate MAGPRO | 94.6 gr | 82% | 38,406 psi | 60% | 2379 fps | 95.5% |
| ADI AR 2209 | <<locked>> | 80% | 41,046 psi | 64% | 2328 fps | 98.4% |
| ADI AR 2213 | <<locked>> | 80% | 36,622 psi | 57% | 2271 fps | 95.9% |
| ADI AR 2217 | <<locked>> | 88% | 35,433 psi | 56% | 2249 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 84% | 28,195 psi | 44% | 2116 fps | 95.6% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 41,394 psi | 65% | 2379 fps | 98.9% |
| Alliant Reloder-16 | <<locked>> | 80% | 47,297 psi | 74% | 2428 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 41,017 psi | 64% | 2322 fps | 98.4% |
| Alliant Reloder-22 | <<locked>> | 80% | 36,927 psi | 58% | 2280 fps | 97.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 35,621 psi | 56% | 2237 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 30,937 psi | 48% | 2175 fps | 98.6% |
| Alliant Reloder-26 | <<locked>> | 80% | 39,204 psi | 61% | 2373 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 45,977 psi | 72% | 2519 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 46,572 psi | 73% | 2405 fps | 95.8% |
| Bofors RP15 | <<locked>> | 80% | 34,403 psi | 54% | 2274 fps | 97.2% |
| Bofors RP30 | <<locked>> | 84% | 32,401 psi | 51% | 2212 fps | 95% |
| Bofors RP5 | <<locked>> | 80% | 36,927 psi | 58% | 2333 fps | 98.1% |
| Bofors RP7 | <<locked>> | 80% | 51,358 psi | 80% | 2422 fps | 100% |
| Hodgdon H1000 | <<locked>> | 84% | 31,908 psi | 50% | 2218 fps | 95.8% |
| Hodgdon H4350 | <<locked>> | 80% | 48,892 psi | 77% | 2461 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 82% | 36,883 psi | 58% | 2231 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 80% | 38,392 psi | 60% | 2261 fps | 95.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,527 psi | 70% | 2321 fps | 100% |
| Hodgdon Retumbo | 87.3 gr | 80% | 30,168 psi | 47% | 2251 fps | 96.4% |
| Hodgdon Superformance | <<locked>> | 80% | 50,589 psi | 79% | 2503 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,108 psi | 44% | 1383 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 54,331 psi | 85% | 2441 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 46,862 psi | 73% | 2415 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,736 psi | 83% | 2487 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 42,641 psi | 67% | 2310 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 40,727 psi | 64% | 2323 fps | 97.4% |
| IMR 7828 SSC | <<locked>> | 80% | 37,550 psi | 59% | 2301 fps | 96.4% |
| IMR 8133 Enduron | <<locked>> | 94% | 35,041 psi | 55% | 2295 fps | 95.9% |
| Lovex S065 | <<locked>> | 80% | 50,285 psi | 79% | 2397 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 48,733 psi | 76% | 2396 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 32,010 psi | 50% | 2113 fps | 98.2% |
| Norma 204 | <<locked>> | 80% | 47,050 psi | 74% | 2411 fps | 99.2% |
| Norma 217 | <<locked>> | 88% | 28,921 psi | 45% | 2162 fps | 95.5% |
| Norma MRP | <<locked>> | 80% | 38,682 psi | 61% | 2340 fps | 99% |
| Norma URP | <<locked>> | 80% | 48,167 psi | 75% | 2410 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 38,957 psi | 61% | 2346 fps | 97.3% |
| Ramshot Hunter | <<locked>> | 80% | 46,978 psi | 74% | 2417 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 34,040 psi | 53% | 2225 fps | 97.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,718 psi | 45% | 1416 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 49,240 psi | 77% | 2447 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 47,369 psi | 74% | 2466 fps | 100% |
| ReloadSwiss RS 76 | 93.4 gr | 80% | 29,008 psi | 45% | 2167 fps | 96% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 37,275 psi | 58% | 2356 fps | 95.1% |
| Rottweil R 904 | <<locked>> | 80% | 42,279 psi | 66% | 2307 fps | 97.7% |
| Rottweil R 905 | <<locked>> | 80% | 40,509 psi | 63% | 2312 fps | 98.4% |
| Rottweil R 907 | <<locked>> | 80% | 51,358 psi | 80% | 2422 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,285 psi | 79% | 2397 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 48,733 psi | 76% | 2441 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,182 psi | 77% | 2356 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 40,190 psi | 63% | 2359 fps | 98.8% |
| Somchem S361 | <<locked>> | 80% | 42,888 psi | 67% | 2300 fps | 97.1% |
| Somchem S365 | <<locked>> | 80% | 45,440 psi | 71% | 2371 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 41,002 psi | 64% | 2295 fps | 99% |
| Unknown powder | <<locked>> | 80% | 51,329 psi | 80% | 2455 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 48,124 psi | 75% | 2319 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 51,474 psi | 81% | 2427 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 34,621 psi | 54% | 2167 fps | 97.3% |
| Vihtavuori N550 | <<locked>> | 80% | 52,083 psi | 82% | 2468 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 39,943 psi | 63% | 2303 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 36,927 psi | 58% | 2294 fps | 95.6% |
| Vihtavuori N565 | <<locked>> | 84% | 36,593 psi | 57% | 2280 fps | 95.8% |
| Vihtavuori N568 | <<locked>> | 90% | 38,856 psi | 61% | 2372 fps | 95.1% |
| Vihtavuori N570 | <<locked>> | 96% | 45,658 psi | 72% | 2528 fps | 95.1% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 48,486 psi | 76% | 2365 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 32,053 psi | 50% | 2276 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 40,828 psi | 64% | 2296 fps | 98.3% |
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 73 powders for .378 Weath. Mag. loaded with the .375 | 350gr | Woodleigh RN SN. Hodgdon Retumbo delivers the highest muzzle velocity at 2,740 fps; across all powders the maximum-charge window runs from 1,551 fps to 2,740 fps. ADI AR 2217 gives the best case fill at 100 %, and 73 of the 73 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 59–90 %, leaving at least 10 % headroom. The 350.0 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-33 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. Hodgdon Retumbo, Accurate MAGPRO, ReloadSwiss RS 76 rank at the top here: for .378 Weath. Mag. with the .375 | 350gr | Woodleigh RN SN 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.