Load Specifications
Load data in caliber .375 Weath. Mag. with .375 | 270gr | Impala RNFP KO bullet and 99 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Power Pro 2000-MR, Alliant Reloder-17 and ReloadSwiss RS 60.
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: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 84% | 55,259 psi | 87% | 2539 fps | 100% |
| Accurate 2460 | <<locked>> | 82% | 57,159 psi | 90% | 2608 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 54,766 psi | 86% | 2572 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 55,172 psi | 86% | 2621 fps | 100% |
| Accurate 2700 | <<locked>> | 90% | 55,912 psi | 88% | 2595 fps | 96.6% |
| Accurate 4064 | <<locked>> | 92% | 57,638 psi | 90% | 2657 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 56,028 psi | 88% | 2723 fps | 99.5% |
| ADI AR 2206H | <<locked>> | 88% | 57,101 psi | 89% | 2674 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 94% | 57,740 psi | 90% | 2671 fps | 99.8% |
| ADI Benchmark 8208 | <<locked>> | 86% | 56,057 psi | 88% | 2628 fps | 100% |
| Alliant AR-Comp | <<locked>> | 86% | 56,971 psi | 89% | 2605 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 90% | 56,115 psi | 88% | 2782 fps | 99.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 57,711 psi | 90% | 2690 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 90% | 55,172 psi | 86% | 2667 fps | 99.7% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 53,374 psi | 84% | 2717 fps | 99.5% |
| Alliant Reloder-17 | <<locked>> | 96% | 54,621 psi | 86% | 2759 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 39,059 psi | 61% | 2487 fps | 98.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 43,091 psi | 68% | 2625 fps | 97.1% |
| Baschieri & Pellagri 107 | <<locked>> | 88% | 56,521 psi | 89% | 2687 fps | 99.6% |
| Bofors RP3 | <<locked>> | 92% | 55,463 psi | 87% | 2667 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 55,288 psi | 87% | 2628 fps | 96.8% |
| Hodgdon Benchmark | <<locked>> | 86% | 57,653 psi | 90% | 2608 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 55,317 psi | 87% | 2657 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 84% | 56,927 psi | 89% | 2749 fps | 99.8% |
| Hodgdon H322 | <<locked>> | 82% | 56,536 psi | 89% | 2618 fps | 100% |
| Hodgdon H380 | <<locked>> | 92% | 56,072 psi | 88% | 2674 fps | 99.2% |
| Hodgdon H414 | <<locked>> | 98% | 54,998 psi | 86% | 2717 fps | 97.5% |
| Hodgdon H4350 | <<locked>> | 96% | 55,883 psi | 88% | 2677 fps | 96.2% |
| Hodgdon H4895 | <<locked>> | 88% | 57,667 psi | 90% | 2684 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 49,864 psi | 78% | 2608 fps | 99.8% |
| Hodgdon LEVERevolution | <<locked>> | 90% | 56,594 psi | 89% | 2713 fps | 100% |
| Hodgdon Superformance | <<locked>> | 98% | 55,695 psi | 87% | 2746 fps | 97% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,839 psi | 56% | 1591 fps | 100% |
| Hodgdon VARGET | <<locked>> | 88% | 55,027 psi | 86% | 2635 fps | 100% |
| IMR 3031 | <<locked>> | 88% | 57,435 psi | 90% | 2664 fps | 100% |
| IMR 4064 | <<locked>> | 92% | 57,276 psi | 90% | 2654 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 90% | 57,479 psi | 90% | 2635 fps | 97.7% |
| IMR 4198 | <<locked>> | 82% | 57,276 psi | 90% | 2533 fps | 100% |
| IMR 4350ᴾ | <<locked>> | 100% | 54,853 psi | 86% | 2648 fps | 96.7% |
| IMR 4451 Enduron | <<locked>> | 96% | 56,710 psi | 89% | 2654 fps | 97.5% |
| IMR 4831ᴾ | <<locked>> | 100% | 52,910 psi | 83% | 2664 fps | 99.3% |
| IMR 4895 | <<locked>> | 90% | 56,550 psi | 89% | 2697 fps | 99.9% |
| IMR 8208 XBR | <<locked>> | 86% | 56,057 psi | 88% | 2628 fps | 100% |
| Lovex D073.5 | <<locked>> | 82% | 57,014 psi | 89% | 2621 fps | 100% |
| Lovex D073.6 | <<locked>> | 88% | 57,174 psi | 90% | 2657 fps | 100% |
| Lovex S060 | <<locked>> | 88% | 56,521 psi | 89% | 2602 fps | 99.9% |
| Lovex S062 | <<locked>> | 92% | 57,522 psi | 90% | 2654 fps | 100% |
| Lovex S065 | <<locked>> | 98% | 56,391 psi | 88% | 2654 fps | 98.7% |
| Lovex S070ᴾ | <<locked>> | 100% | 57,334 psi | 90% | 2687 fps | 97.9% |
| Norma 201 | <<locked>> | 88% | 56,420 psi | 88% | 2628 fps | 100% |
| Norma 202 | <<locked>> | 88% | 56,376 psi | 88% | 2625 fps | 100% |
| Norma 203B | <<locked>> | 90% | 54,462 psi | 85% | 2657 fps | 99.9% |
| Norma URPᴾ | <<locked>> | 100% | 54,766 psi | 86% | 2710 fps | 99.4% |
| Ramshot Big Game | <<locked>> | 90% | 54,230 psi | 85% | 2674 fps | 99.8% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 53,403 psi | 84% | 2700 fps | 98% |
| Ramshot TAC | <<locked>> | 86% | 56,159 psi | 88% | 2644 fps | 98.8% |
| Ramshot Wild Boar | <<locked>> | 86% | 55,811 psi | 87% | 2664 fps | 99.9% |
| Ramshot X-Terminator | <<locked>> | 84% | 56,942 psi | 89% | 2631 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,347 psi | 57% | 1631 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 55,550 psi | 87% | 2608 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 56,275 psi | 88% | 2654 fps | 98.1% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 55,288 psi | 87% | 2730 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 54,317 psi | 85% | 2756 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 55,071 psi | 86% | 2740 fps | 99.3% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 55,013 psi | 86% | 2762 fps | 99% |
| Rottweil R 901 | <<locked>> | 84% | 54,853 psi | 86% | 2572 fps | 100% |
| Rottweil R 902 | <<locked>> | 90% | 56,811 psi | 89% | 2625 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 55,114 psi | 86% | 2657 fps | 100% |
| Rottweil R 907 | <<locked>> | 96% | 55,288 psi | 87% | 2628 fps | 96.8% |
| Shooters World Long Rifle | <<locked>> | 98% | 56,391 psi | 88% | 2654 fps | 98.7% |
| Shooters World Match Rifle | <<locked>> | 88% | 57,174 psi | 90% | 2657 fps | 100% |
| Shooters World Precision | <<locked>> | 92% | 57,522 psi | 90% | 2654 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 57,334 psi | 90% | 2687 fps | 97.9% |
| SNPE Vectan SP 11 | <<locked>> | 94% | 56,130 psi | 88% | 2707 fps | 99.9% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 55,085 psi | 86% | 2628 fps | 99% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 55,347 psi | 87% | 2648 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 88% | 57,537 psi | 90% | 2566 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 57,305 psi | 90% | 2562 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 56,942 psi | 89% | 2608 fps | 97.5% |
| Somchem S321 | <<locked>> | 84% | 57,493 psi | 90% | 2661 fps | 100% |
| Somchem S335 | <<locked>> | 88% | 57,043 psi | 89% | 2566 fps | 100% |
| Somchem S341 | <<locked>> | 88% | 57,740 psi | 90% | 2664 fps | 99.9% |
| Somchem S355 | <<locked>> | 94% | 55,376 psi | 87% | 2654 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 49,313 psi | 77% | 2667 fps | 100% |
| Vihtavuori N130 | <<locked>> | 84% | 57,363 psi | 90% | 2530 fps | 100% |
| Vihtavuori N133 | <<locked>> | 88% | 57,537 psi | 90% | 2549 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 56,188 psi | 88% | 2589 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 56,710 psi | 89% | 2605 fps | 100% |
| Vihtavuori N150 | <<locked>> | 96% | 56,536 psi | 89% | 2631 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 57,174 psi | 90% | 2700 fps | 99.5% |
| Vihtavuori N530 | <<locked>> | 86% | 56,565 psi | 89% | 2628 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 54,955 psi | 86% | 2602 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 56,260 psi | 88% | 2710 fps | 99.3% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 42,380 psi | 66% | 2559 fps | 98.2% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 54,157 psi | 85% | 2638 fps | 100% |
| Winchester 748 | <<locked>> | 86% | 56,304 psi | 88% | 2674 fps | 100% |
| Winchester 760 | <<locked>> | 98% | 54,998 psi | 86% | 2717 fps | 97.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 35,230 psi | 55% | 2484 fps | 97.9% |
| Winchester StaBALL Match | <<locked>> | 88% | 55,129 psi | 86% | 2654 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 49,153 psi | 77% | 2457 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 53,693 psi | 84% | 2562 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 43,018 psi | 67% | 2405 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 48,718 psi | 76% | 2530 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 49,443 psi | 77% | 2500 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 40,596 psi | 64% | 2402 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 35,940 psi | 56% | 2379 fps | 95.7% |
| ADI AR 2206H | <<locked>> | 80% | 45,049 psi | 71% | 2487 fps | 99% |
| ADI AR 2208 | <<locked>> | 80% | 38,363 psi | 60% | 2346 fps | 97% |
| ADI Benchmark 8208 | <<locked>> | 80% | 46,876 psi | 73% | 2490 fps | 99.8% |
| Alliant AR-Comp | <<locked>> | 80% | 47,079 psi | 74% | 2480 fps | 100% |
| Alliant Power Pro 2000-MR | 67.8 gr | 80% | 40,799 psi | 64% | 2510 fps | 97.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 38,363 psi | 60% | 2375 fps | 98.5% |
| Alliant Reloder-15 | <<locked>> | 80% | 40,930 psi | 64% | 2428 fps | 97.8% |
| Alliant Reloder-16 | <<locked>> | 86% | 35,752 psi | 56% | 2375 fps | 95.5% |
| Alliant Reloder-17 | 66.7 gr | 80% | 33,141 psi | 52% | 2343 fps | 96.4% |
| Alliant Reloder-23 | <<locked>> | 92% | 31,343 psi | 49% | 2297 fps | 95.4% |
| Alliant Reloder-26 | <<locked>> | 96% | 37,942 psi | 59% | 2513 fps | 95.3% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 43,990 psi | 69% | 2487 fps | 97.9% |
| Bofors RP3 | <<locked>> | 80% | 38,276 psi | 60% | 2385 fps | 98.6% |
| Bofors RP7 | <<locked>> | 92% | 49,211 psi | 77% | 2533 fps | 95.5% |
| Hodgdon Benchmark | <<locked>> | 80% | 48,544 psi | 76% | 2477 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 45,919 psi | 72% | 2516 fps | 99.9% |
| Hodgdon CFE223 | <<locked>> | 80% | 49,951 psi | 78% | 2644 fps | 99.3% |
| Hodgdon H322 | <<locked>> | 80% | 53,098 psi | 83% | 2572 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 38,885 psi | 61% | 2379 fps | 95.9% |
| Hodgdon H414 | <<locked>> | 92% | 45,658 psi | 72% | 2566 fps | 95.5% |
| Hodgdon H4350 | <<locked>> | 94% | 52,620 psi | 82% | 2628 fps | 95.5% |
| Hodgdon H4895 | <<locked>> | 80% | 45,440 psi | 71% | 2497 fps | 99.4% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 31,270 psi | 49% | 2241 fps | 95.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 41,147 psi | 64% | 2470 fps | 99.1% |
| Hodgdon Superformance | <<locked>> | 94% | 48,718 psi | 76% | 2631 fps | 95.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,789 psi | 42% | 1421 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 43,410 psi | 68% | 2448 fps | 99% |
| IMR 3031 | <<locked>> | 80% | 45,049 psi | 71% | 2493 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 40,277 psi | 63% | 2375 fps | 97.7% |
| IMR 4166 Enduron | <<locked>> | 82% | 45,310 psi | 71% | 2441 fps | 95.2% |
| IMR 4198 | <<locked>> | 80% | 54,041 psi | 85% | 2493 fps | 100% |
| IMR 4350 | <<locked>> | 96% | 48,718 psi | 76% | 2552 fps | 95.4% |
| IMR 4451 Enduron | <<locked>> | 88% | 45,020 psi | 71% | 2464 fps | 95% |
| IMR 4831 | <<locked>> | 86% | 34,606 psi | 54% | 2333 fps | 95.3% |
| IMR 4895 | <<locked>> | 80% | 41,872 psi | 66% | 2457 fps | 98.5% |
| IMR 8208 XBR | <<locked>> | 80% | 46,876 psi | 73% | 2490 fps | 99.8% |
| Lovex D073.5 | <<locked>> | 80% | 53,330 psi | 84% | 2572 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 44,570 psi | 70% | 2474 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 45,020 psi | 71% | 2425 fps | 99% |
| Lovex S062 | <<locked>> | 80% | 40,669 psi | 64% | 2388 fps | 99.2% |
| Lovex S065 | <<locked>> | 86% | 40,103 psi | 63% | 2382 fps | 95.3% |
| Lovex S070 | <<locked>> | 92% | 45,411 psi | 71% | 2500 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 44,628 psi | 70% | 2448 fps | 99.6% |
| Norma 202 | <<locked>> | 80% | 44,599 psi | 70% | 2454 fps | 100% |
| Norma 203B | <<locked>> | 80% | 40,364 psi | 63% | 2421 fps | 98.2% |
| Norma URP | <<locked>> | 86% | 35,810 psi | 56% | 2372 fps | 95.4% |
| Ramshot Big Game | <<locked>> | 80% | 39,595 psi | 62% | 2428 fps | 97.8% |
| Ramshot Hunter | <<locked>> | 92% | 41,843 psi | 66% | 2500 fps | 95.2% |
| Ramshot TAC | <<locked>> | 80% | 46,731 psi | 73% | 2493 fps | 97.2% |
| Ramshot Wild Boar | <<locked>> | 80% | 46,282 psi | 73% | 2516 fps | 99.1% |
| Ramshot X-Terminator | <<locked>> | 80% | 50,415 psi | 79% | 2533 fps | 99.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,340 psi | 43% | 1457 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 52,315 psi | 82% | 2562 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 44,150 psi | 69% | 2457 fps | 95.6% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 42,554 psi | 67% | 2523 fps | 98.2% |
| ReloadSwiss RS 60 | 66.7 gr | 80% | 35,114 psi | 55% | 2405 fps | 99.2% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 35,418 psi | 56% | 2388 fps | 95% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 40,016 psi | 63% | 2487 fps | 95.5% |
| Rottweil R 901 | <<locked>> | 80% | 48,936 psi | 77% | 2487 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 42,627 psi | 67% | 2405 fps | 99.4% |
| Rottweil R 903 | <<locked>> | 80% | 36,201 psi | 57% | 2333 fps | 97.8% |
| Rottweil R 907 | <<locked>> | 92% | 49,211 psi | 77% | 2533 fps | 95.5% |
| Shooters World Long Rifle | <<locked>> | 86% | 40,103 psi | 63% | 2382 fps | 95.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 44,570 psi | 70% | 2474 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 40,669 psi | 64% | 2388 fps | 99.2% |
| Shooters World SW4350 | <<locked>> | 92% | 45,411 psi | 71% | 2500 fps | 95.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 36,477 psi | 57% | 2369 fps | 97.1% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 45,353 psi | 71% | 2474 fps | 97.5% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 43,410 psi | 68% | 2457 fps | 98.7% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 45,658 psi | 72% | 2398 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 38,189 psi | 60% | 2280 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 44,367 psi | 70% | 2418 fps | 95% |
| Somchem S321 | <<locked>> | 80% | 50,705 psi | 79% | 2566 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 45,339 psi | 71% | 2402 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 44,802 psi | 70% | 2470 fps | 98.9% |
| Somchem S355 | <<locked>> | 80% | 36,825 psi | 58% | 2336 fps | 97.8% |
| Somchem S365 | <<locked>> | 80% | 27,369 psi | 43% | 2188 fps | 95.4% |
| Vihtavuori N130 | <<locked>> | 80% | 51,256 psi | 80% | 2451 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 45,818 psi | 72% | 2392 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 41,916 psi | 66% | 2388 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 42,148 psi | 66% | 2392 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 34,983 psi | 55% | 2277 fps | 98.5% |
| Vihtavuori N160 | <<locked>> | 84% | 35,215 psi | 55% | 2323 fps | 95.1% |
| Vihtavuori N530 | <<locked>> | 80% | 47,007 psi | 74% | 2487 fps | 99.8% |
| Vihtavuori N540 | <<locked>> | 80% | 40,712 psi | 64% | 2385 fps | 100% |
| Vihtavuori N550 | <<locked>> | 86% | 36,854 psi | 58% | 2375 fps | 95.5% |
| Vihtavuori N555 | <<locked>> | 92% | 33,431 psi | 52% | 2369 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 31,154 psi | 49% | 2208 fps | 95.7% |
| Winchester 748 | <<locked>> | 80% | 46,528 psi | 73% | 2530 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 45,658 psi | 72% | 2566 fps | 95.5% |
| Winchester StaBALL HD | <<locked>> | 96% | 31,386 psi | 49% | 2369 fps | 95.7% |
| Winchester StaBALL Match | <<locked>> | 80% | 42,873 psi | 67% | 2464 fps | 99% |
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 116 powders for .375 Weath. Mag. loaded with the .375 | 270gr | Impala RNFP KO. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,782 fps; across all powders the maximum-charge window runs from 1,591 fps to 2,782 fps. Accurate 3100 gives the best case fill at 100 %, and 116 of the 116 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 54–90 %, 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. Accurate 3100, Accurate 4350, ADI AR 2209 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 Power Pro 2000-MR, Alliant Reloder-17, ReloadSwiss RS 60 rank at the top here: for .375 Weath. Mag. with the .375 | 270gr | Impala RNFP KO they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2209, Alliant Reloder-19, Alliant Reloder-22 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.