Load Specifications
Load data in caliber .375 H&H Mag. with .375 | 250gr | NorthFork Bonded Core bullet and 95 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, Hodgdon CFE223 and ReloadSwiss RS 52.
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>> | 90% | 55,840 psi | 90% | 2638 fps | 100% |
| Accurate 2200 | <<locked>> | 82% | 55,840 psi | 90% | 2726 fps | 98.9% |
| Accurate 2460 | <<locked>> | 86% | 54,186 psi | 87% | 2661 fps | 100% |
| Accurate 2495 | <<locked>> | 96% | 56,304 psi | 90% | 2694 fps | 100% |
| Accurate 2520 | <<locked>> | 90% | 55,753 psi | 89% | 2717 fps | 100% |
| Accurate 4064 | <<locked>> | 98% | 55,869 psi | 90% | 2733 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 44,541 psi | 71% | 2628 fps | 96.7% |
| Accurate LT-30 | <<locked>> | 84% | 55,782 psi | 89% | 2589 fps | 100% |
| Accurate LT-32 | <<locked>> | 84% | 56,217 psi | 90% | 2612 fps | 100% |
| ADI AR 2206H | <<locked>> | 92% | 54,679 psi | 88% | 2720 fps | 99.3% |
| ADI AR 2208 | <<locked>> | 98% | 55,419 psi | 89% | 2710 fps | 99% |
| ADI AR 2219 | <<locked>> | 84% | 56,173 psi | 90% | 2700 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 90% | 54,056 psi | 87% | 2680 fps | 99.8% |
| Alliant AR-Comp | <<locked>> | 90% | 53,606 psi | 86% | 2664 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 86% | 55,521 psi | 89% | 2779 fps | 99.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 94% | 53,954 psi | 87% | 2818 fps | 98.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 98% | 54,636 psi | 88% | 2733 fps | 99.8% |
| Alliant Reloder-10x | <<locked>> | 86% | 55,521 psi | 89% | 2644 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 96% | 55,608 psi | 89% | 2753 fps | 99.2% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 44,759 psi | 72% | 2635 fps | 96.8% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 51,721 psi | 83% | 2785 fps | 99.5% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 54,752 psi | 88% | 2585 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 92% | 54,389 psi | 87% | 2733 fps | 98.6% |
| Bofors RP3 | <<locked>> | 98% | 55,013 psi | 88% | 2749 fps | 99.8% |
| Hodgdon Benchmark | <<locked>> | 90% | 56,347 psi | 90% | 2667 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 92% | 56,275 psi | 90% | 2756 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 88% | 54,505 psi | 87% | 2795 fps | 99.1% |
| Hodgdon H322 | <<locked>> | 86% | 54,737 psi | 88% | 2680 fps | 100% |
| Hodgdon H335 | <<locked>> | 86% | 55,854 psi | 90% | 2710 fps | 100% |
| Hodgdon H380 | <<locked>> | 96% | 53,200 psi | 85% | 2707 fps | 97.8% |
| Hodgdon H4895 | <<locked>> | 92% | 55,129 psi | 88% | 2730 fps | 99.7% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 41,075 psi | 66% | 2530 fps | 97.5% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 53,447 psi | 86% | 2756 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,563 psi | 55% | 1614 fps | 100% |
| Hodgdon VARGET | <<locked>> | 92% | 53,258 psi | 85% | 2687 fps | 99.5% |
| IMR 3031 | <<locked>> | 92% | 54,331 psi | 87% | 2723 fps | 100% |
| IMR 4064 | <<locked>> | 96% | 55,071 psi | 88% | 2700 fps | 99.1% |
| IMR 4166 Enduron | <<locked>> | 94% | 55,999 psi | 90% | 2677 fps | 96% |
| IMR 4198 | <<locked>> | 86% | 55,985 psi | 90% | 2605 fps | 100% |
| IMR 4451 Enduronᴾ | <<locked>> | 100% | 54,795 psi | 88% | 2690 fps | 95.7% |
| IMR 4831ᴾ | <<locked>> | 100% | 42,714 psi | 68% | 2579 fps | 96.3% |
| IMR 4895 | <<locked>> | 94% | 53,505 psi | 86% | 2736 fps | 99.3% |
| IMR 8208 XBR | <<locked>> | 90% | 54,056 psi | 87% | 2680 fps | 99.8% |
| Lovex D073.5 | <<locked>> | 86% | 54,143 psi | 87% | 2671 fps | 100% |
| Lovex D073.6 | <<locked>> | 92% | 53,563 psi | 86% | 2700 fps | 100% |
| Lovex S060 | <<locked>> | 92% | 54,969 psi | 88% | 2654 fps | 99.4% |
| Lovex S062 | <<locked>> | 96% | 54,302 psi | 87% | 2697 fps | 99.9% |
| Lovex S065ᴾ | <<locked>> | 100% | 50,227 psi | 81% | 2631 fps | 96.4% |
| Norma 200 | <<locked>> | 82% | 55,680 psi | 89% | 2621 fps | 100% |
| Norma 201 | <<locked>> | 92% | 53,388 psi | 86% | 2671 fps | 99.8% |
| Norma 202 | <<locked>> | 92% | 53,766 psi | 86% | 2677 fps | 100% |
| Norma 203B | <<locked>> | 96% | 54,650 psi | 88% | 2740 fps | 99.4% |
| Norma URPᴾ | <<locked>> | 100% | 44,831 psi | 72% | 2625 fps | 96.6% |
| Ramshot Big Game | <<locked>> | 96% | 55,114 psi | 88% | 2766 fps | 99.3% |
| Ramshot TAC | <<locked>> | 90% | 54,621 psi | 88% | 2690 fps | 97.4% |
| Ramshot Wild Boar | <<locked>> | 90% | 53,534 psi | 86% | 2710 fps | 99.2% |
| Ramshot X-Terminator | <<locked>> | 88% | 55,535 psi | 89% | 2684 fps | 99.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,882 psi | 56% | 1654 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 86% | 53,911 psi | 86% | 2671 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 96% | 53,911 psi | 86% | 2687 fps | 96.4% |
| ReloadSwiss RS 52 | <<locked>> | 94% | 55,419 psi | 89% | 2815 fps | 99.2% |
| ReloadSwiss RS 60ᴾ | <<locked>> | 100% | 55,274 psi | 89% | 2851 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 44,454 psi | 71% | 2648 fps | 96.3% |
| Rottweil R 901 | <<locked>> | 90% | 54,520 psi | 87% | 2657 fps | 100% |
| Rottweil R 902 | <<locked>> | 94% | 53,795 psi | 86% | 2667 fps | 99.8% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 54,621 psi | 88% | 2733 fps | 99.7% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 50,227 psi | 81% | 2631 fps | 96.4% |
| Shooters World Match Rifle | <<locked>> | 92% | 53,563 psi | 86% | 2700 fps | 100% |
| Shooters World Precision | <<locked>> | 96% | 54,302 psi | 87% | 2697 fps | 99.9% |
| Shooters World Tactical Rifle | <<locked>> | 84% | 53,708 psi | 86% | 2638 fps | 99.6% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 56,057 psi | 90% | 2349 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 82% | 52,982 psi | 85% | 2664 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 98% | 53,055 psi | 85% | 2743 fps | 99.2% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 53,345 psi | 86% | 2621 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 92% | 56,144 psi | 90% | 2717 fps | 98.1% |
| SNPE Vectan SP 9 | <<locked>> | 92% | 53,098 psi | 85% | 2694 fps | 99.2% |
| SNPE Vectan Tubal 3000 | <<locked>> | 92% | 55,637 psi | 89% | 2621 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 98% | 55,085 psi | 88% | 2615 fps | 100% |
| Somchem S321 | <<locked>> | 88% | 55,201 psi | 89% | 2713 fps | 99.9% |
| Somchem S335 | <<locked>> | 92% | 54,592 psi | 88% | 2621 fps | 100% |
| Somchem S341 | <<locked>> | 92% | 55,695 psi | 89% | 2713 fps | 99.3% |
| Somchem S355ᴾ | <<locked>> | 100% | 55,376 psi | 89% | 2736 fps | 99.6% |
| Somchem S365ᴾ | <<locked>> | 100% | 39,871 psi | 64% | 2575 fps | 98.6% |
| Vihtavuori N130 | <<locked>> | 88% | 55,535 psi | 89% | 2595 fps | 100% |
| Vihtavuori N133 | <<locked>> | 92% | 55,477 psi | 89% | 2608 fps | 100% |
| Vihtavuori N135 | <<locked>> | 96% | 56,086 psi | 90% | 2684 fps | 100% |
| Vihtavuori N140 | <<locked>> | 94% | 54,099 psi | 87% | 2654 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 53,534 psi | 86% | 2671 fps | 99.9% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 47,268 psi | 76% | 2628 fps | 97% |
| Vihtavuori N530 | <<locked>> | 90% | 54,520 psi | 87% | 2677 fps | 99.8% |
| Vihtavuori N540 | <<locked>> | 96% | 55,869 psi | 90% | 2700 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 46,151 psi | 74% | 2628 fps | 96.7% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 48,501 psi | 78% | 2618 fps | 99% |
| Winchester 748 | <<locked>> | 90% | 53,751 psi | 86% | 2726 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 94% | 56,057 psi | 90% | 2749 fps | 99.7% |
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% | 40,973 psi | 66% | 2421 fps | 100% |
| Accurate 2200 | <<locked>> | 80% | 52,330 psi | 84% | 2674 fps | 98.5% |
| Accurate 2460 | <<locked>> | 80% | 44,367 psi | 71% | 2513 fps | 99.9% |
| Accurate 2495 | <<locked>> | 80% | 33,431 psi | 54% | 2333 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 39,697 psi | 64% | 2467 fps | 99.3% |
| Accurate 4064 | <<locked>> | 80% | 31,618 psi | 51% | 2313 fps | 98.5% |
| Accurate 4350 | <<locked>> | 96% | 38,740 psi | 62% | 2520 fps | 95.1% |
| Accurate LT-30 | <<locked>> | 80% | 49,429 psi | 79% | 2500 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 49,806 psi | 80% | 2520 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 37,579 psi | 60% | 2418 fps | 96.1% |
| ADI AR 2208 | <<locked>> | 86% | 38,566 psi | 62% | 2421 fps | 95.6% |
| ADI AR 2219 | <<locked>> | 80% | 49,124 psi | 79% | 2605 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 39,566 psi | 63% | 2434 fps | 97.9% |
| Alliant AR-Comp | <<locked>> | 80% | 38,363 psi | 62% | 2441 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 45,672 psi | 73% | 2621 fps | 98.7% |
| Alliant Power Pro 2000-MR | 68.8 gr | 86% | 41,263 psi | 66% | 2585 fps | 96% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 33,011 psi | 53% | 2343 fps | 95.7% |
| Alliant Reloder-10x | <<locked>> | 80% | 46,412 psi | 74% | 2516 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 38,101 psi | 61% | 2451 fps | 95.7% |
| Alliant Reloder-16 | <<locked>> | 96% | 39,769 psi | 64% | 2533 fps | 95.2% |
| Alliant Reloder-17 | <<locked>> | 88% | 34,795 psi | 56% | 2451 fps | 95.3% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 48,269 psi | 77% | 2497 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 38,943 psi | 62% | 2464 fps | 95.2% |
| Bofors RP3 | <<locked>> | 82% | 32,358 psi | 52% | 2339 fps | 95.6% |
| Hodgdon Benchmark | <<locked>> | 80% | 41,698 psi | 67% | 2438 fps | 98.8% |
| Hodgdon BL-C2 | <<locked>> | 80% | 37,507 psi | 60% | 2444 fps | 98% |
| Hodgdon CFE223 | 65.5 gr | 80% | 41,147 psi | 66% | 2566 fps | 96.6% |
| Hodgdon H322 | <<locked>> | 80% | 44,991 psi | 72% | 2539 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 45,687 psi | 73% | 2559 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 40,799 psi | 65% | 2493 fps | 95% |
| Hodgdon H4895 | <<locked>> | 80% | 37,826 psi | 61% | 2431 fps | 96.9% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 34,069 psi | 55% | 2379 fps | 95.1% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 33,808 psi | 54% | 2392 fps | 96% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,599 psi | 41% | 1440 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 36,434 psi | 58% | 2385 fps | 96.3% |
| IMR 3031 | <<locked>> | 80% | 36,724 psi | 59% | 2441 fps | 99.9% |
| IMR 4064 | <<locked>> | 84% | 37,956 psi | 61% | 2405 fps | 95.7% |
| IMR 4166 Enduron | <<locked>> | 92% | 52,692 psi | 84% | 2628 fps | 95.3% |
| IMR 4198 | <<locked>> | 80% | 47,079 psi | 75% | 2484 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 98% | 51,488 psi | 83% | 2638 fps | 95% |
| IMR 4831 | <<locked>> | 98% | 40,016 psi | 64% | 2526 fps | 95.5% |
| IMR 4895 | <<locked>> | 80% | 34,287 psi | 55% | 2379 fps | 95.1% |
| IMR 8208 XBR | <<locked>> | 80% | 39,566 psi | 63% | 2434 fps | 97.9% |
| Lovex D073.5 | <<locked>> | 80% | 44,222 psi | 71% | 2520 fps | 99.4% |
| Lovex D073.6 | <<locked>> | 80% | 35,766 psi | 57% | 2398 fps | 98.6% |
| Lovex S060 | <<locked>> | 80% | 38,464 psi | 62% | 2372 fps | 96.4% |
| Lovex S062 | <<locked>> | 80% | 33,272 psi | 53% | 2316 fps | 96.3% |
| Lovex S065 | <<locked>> | 98% | 47,181 psi | 76% | 2582 fps | 95.7% |
| Norma 200 | <<locked>> | 80% | 52,286 psi | 84% | 2575 fps | 100% |
| Norma 201 | <<locked>> | 80% | 36,883 psi | 59% | 2382 fps | 97.4% |
| Norma 202 | <<locked>> | 80% | 36,825 psi | 59% | 2395 fps | 99.2% |
| Norma 203B | <<locked>> | 82% | 35,114 psi | 56% | 2392 fps | 95.4% |
| Norma URP | <<locked>> | 96% | 39,436 psi | 63% | 2520 fps | 95% |
| Ramshot Big Game | <<locked>> | 84% | 36,941 psi | 59% | 2448 fps | 95.6% |
| Ramshot TAC | <<locked>> | 84% | 44,918 psi | 72% | 2530 fps | 95.3% |
| Ramshot Wild Boar | <<locked>> | 80% | 38,421 psi | 62% | 2448 fps | 96.3% |
| Ramshot X-Terminator | <<locked>> | 80% | 42,801 psi | 69% | 2477 fps | 97.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,802 psi | 41% | 1473 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 44,440 psi | 71% | 2523 fps | 99.6% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 50,415 psi | 81% | 2635 fps | 95.6% |
| ReloadSwiss RS 52 | 63.6 gr | 82% | 36,840 psi | 59% | 2487 fps | 95.2% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 28,660 psi | 46% | 2293 fps | 95% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 41,553 psi | 67% | 2592 fps | 95.4% |
| Rottweil R 901 | <<locked>> | 80% | 40,640 psi | 65% | 2434 fps | 99.5% |
| Rottweil R 902 | <<locked>> | 80% | 35,012 psi | 56% | 2333 fps | 96.8% |
| Rottweil R 903 | <<locked>> | 84% | 32,416 psi | 52% | 2336 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 98% | 47,181 psi | 76% | 2582 fps | 95.7% |
| Shooters World Match Rifle | <<locked>> | 80% | 35,766 psi | 57% | 2398 fps | 98.6% |
| Shooters World Precision | <<locked>> | 80% | 33,272 psi | 53% | 2316 fps | 96.3% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 46,905 psi | 75% | 2536 fps | 99% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 53,316 psi | 85% | 2316 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 49,632 psi | 80% | 2615 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 36,042 psi | 58% | 2434 fps | 95.4% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 47,007 psi | 75% | 2530 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 42,786 psi | 69% | 2503 fps | 95.4% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 36,027 psi | 58% | 2385 fps | 95.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 38,522 psi | 62% | 2356 fps | 99.4% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 31,575 psi | 51% | 2224 fps | 98.9% |
| Somchem S321 | <<locked>> | 80% | 42,366 psi | 68% | 2510 fps | 98.7% |
| Somchem S335 | <<locked>> | 80% | 38,029 psi | 61% | 2359 fps | 99.7% |
| Somchem S341 | <<locked>> | 80% | 37,115 psi | 60% | 2402 fps | 95.8% |
| Somchem S355 | <<locked>> | 84% | 33,591 psi | 54% | 2346 fps | 95.4% |
| Somchem S365 | <<locked>> | 92% | 30,995 psi | 50% | 2365 fps | 95.5% |
| Vihtavuori N130 | <<locked>> | 80% | 43,700 psi | 70% | 2428 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 38,609 psi | 62% | 2356 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 33,823 psi | 54% | 2333 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 34,766 psi | 56% | 2336 fps | 99.1% |
| Vihtavuori N150 | <<locked>> | 82% | 29,878 psi | 48% | 2241 fps | 95.5% |
| Vihtavuori N160 | <<locked>> | 96% | 41,568 psi | 67% | 2526 fps | 95.6% |
| Vihtavuori N530 | <<locked>> | 80% | 39,334 psi | 63% | 2428 fps | 98% |
| Vihtavuori N540 | <<locked>> | 80% | 33,475 psi | 54% | 2323 fps | 98.4% |
| Vihtavuori N550 | <<locked>> | 96% | 40,654 psi | 65% | 2530 fps | 95.1% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 34,954 psi | 56% | 2359 fps | 95.5% |
| Winchester 748 | <<locked>> | 80% | 38,261 psi | 61% | 2467 fps | 98.5% |
| Winchester StaBALL Match | <<locked>> | 80% | 35,244 psi | 57% | 2388 fps | 96.1% |
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 95 powders for .375 H&H Mag. loaded with the .375 | 250gr | NorthFork Bonded Core. ReloadSwiss RS 60 delivers the highest muzzle velocity at 2,851 fps; across all powders the maximum-charge window runs from 1,614 fps to 2,851 fps. Accurate 4350 gives the best case fill at 100 %, and 95 of the 95 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (430 MPa), the top charges use 55–90 %, leaving at least 10 % headroom. The 250.0 gr projectile in 0.375" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 4350, Alliant Reloder-16, Alliant Reloder-17 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, Hodgdon CFE223, ReloadSwiss RS 52 rank at the top here: for .375 H&H Mag. with the .375 | 250gr | NorthFork Bonded Core 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.