Load Specifications
Bullet Manufacturer:Speer
Bullet Weight:285 gr
Bullet Diameter:0.375"
Bullet Length:<<locked>>
Caliber:.375 H&H Mag. load data
Case Length (l3):2.859"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:95.3 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:24"
Max. allowed Pressure:62,366 psi
Recommended Twist Rate:1:6.0
Load data in caliber .375 H&H Mag. with .375 | 285gr | Speer Grand Slam bullet and 105 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 60, Alliant Power Pro 2000-MR 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.
A valid access license is required to use the Personalized Load Calculator.
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>> | 86% | 53,940 psi | 86% | 2438 fps | 100% |
| Accurate 2460 | <<locked>> | 84% | 55,738 psi | 89% | 2503 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 55,056 psi | 88% | 2497 fps | 100% |
| Accurate 2520 | <<locked>> | 88% | 55,709 psi | 89% | 2549 fps | 100% |
| Accurate 2700 | <<locked>> | 96% | 56,173 psi | 90% | 2500 fps | 96.7% |
| Accurate 4064 | <<locked>> | 94% | 54,897 psi | 88% | 2536 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 50,560 psi | 81% | 2559 fps | 99% |
| Accurate LT-30 | <<locked>> | 82% | 56,434 psi | 90% | 2425 fps | 100% |
| ADI AR 2206H | <<locked>> | 90% | 56,115 psi | 90% | 2569 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 94% | 53,838 psi | 86% | 2523 fps | 99.6% |
| ADI Benchmark 8208 | <<locked>> | 88% | 55,506 psi | 89% | 2530 fps | 100% |
| Alliant AR-Comp | <<locked>> | 88% | 55,680 psi | 89% | 2503 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 82% | 53,679 psi | 86% | 2575 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 92% | 55,695 psi | 89% | 2677 fps | 99.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 53,403 psi | 86% | 2543 fps | 100% |
| Alliant Reloder-10x | <<locked>> | 82% | 53,780 psi | 86% | 2441 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 92% | 53,969 psi | 87% | 2559 fps | 99.7% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 49,371 psi | 79% | 2562 fps | 99.1% |
| Alliant Reloder-17 | <<locked>> | 98% | 53,534 psi | 86% | 2648 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 34,983 psi | 56% | 2320 fps | 97.2% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 55,463 psi | 89% | 2425 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 90% | 55,912 psi | 90% | 2585 fps | 99.6% |
| Bofors RP3 | <<locked>> | 94% | 53,751 psi | 86% | 2556 fps | 100% |
| Bofors RP7 | <<locked>> | 98% | 54,143 psi | 87% | 2520 fps | 96.7% |
| Hodgdon Benchmark | <<locked>> | 86% | 54,099 psi | 87% | 2467 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 54,331 psi | 87% | 2556 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 86% | 56,318 psi | 90% | 2644 fps | 99.9% |
| Hodgdon H322 | <<locked>> | 86% | 55,419 psi | 89% | 2510 fps | 100% |
| Hodgdon H380 | <<locked>> | 94% | 54,897 psi | 88% | 2566 fps | 99.1% |
| Hodgdon H414 | <<locked>> | 98% | 55,724 psi | 89% | 2631 fps | 97.7% |
| Hodgdon H4350ᴾ | <<locked>> | 100% | 52,895 psi | 85% | 2543 fps | 95.7% |
| Hodgdon H4895 | <<locked>> | 88% | 53,447 psi | 86% | 2536 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 45,498 psi | 73% | 2454 fps | 99.4% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 55,506 psi | 89% | 2608 fps | 100% |
| Hodgdon Superformanceᴾ | <<locked>> | 100% | 54,969 psi | 88% | 2641 fps | 97% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,143 psi | 56% | 1512 fps | 100% |
| Hodgdon VARGET | <<locked>> | 92% | 53,432 psi | 86% | 2520 fps | 99.9% |
| IMR 3031 | <<locked>> | 92% | 54,708 psi | 88% | 2539 fps | 100% |
| IMR 4064 | <<locked>> | 96% | 55,564 psi | 89% | 2536 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 96% | 55,521 psi | 89% | 2513 fps | 97.5% |
| IMR 4198 | <<locked>> | 82% | 53,940 psi | 86% | 2398 fps | 100% |
| IMR 4350ᴾ | <<locked>> | 100% | 50,865 psi | 82% | 2497 fps | 96.1% |
| IMR 4451 Enduron | <<locked>> | 98% | 56,246 psi | 90% | 2552 fps | 97.5% |
| IMR 4831ᴾ | <<locked>> | 100% | 42,670 psi | 68% | 2421 fps | 97.8% |
| IMR 4895 | <<locked>> | 92% | 55,347 psi | 89% | 2589 fps | 99.9% |
| IMR 8208 XBR | <<locked>> | 88% | 55,506 psi | 89% | 2530 fps | 100% |
| Lovex D073.4 | <<locked>> | 82% | 54,447 psi | 87% | 2490 fps | 100% |
| Lovex D073.5 | <<locked>> | 84% | 55,579 psi | 89% | 2516 fps | 100% |
| Lovex D073.6 | <<locked>> | 90% | 55,709 psi | 89% | 2549 fps | 100% |
| Lovex S060 | <<locked>> | 90% | 56,072 psi | 90% | 2503 fps | 99.9% |
| Lovex S062 | <<locked>> | 94% | 56,159 psi | 90% | 2546 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 55,071 psi | 88% | 2546 fps | 98.6% |
| Lovex S070ᴾ | <<locked>> | 100% | 52,634 psi | 84% | 2530 fps | 97.3% |
| Norma 201 | <<locked>> | 90% | 54,969 psi | 88% | 2520 fps | 100% |
| Norma 202 | <<locked>> | 90% | 55,506 psi | 89% | 2523 fps | 100% |
| Norma 203B | <<locked>> | 92% | 53,127 psi | 85% | 2549 fps | 99.8% |
| Norma URPᴾ | <<locked>> | 100% | 50,125 psi | 80% | 2552 fps | 98.9% |
| Ramshot Big Game | <<locked>> | 92% | 53,505 psi | 86% | 2575 fps | 99.8% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 49,095 psi | 79% | 2543 fps | 97.3% |
| Ramshot TAC | <<locked>> | 88% | 55,854 psi | 90% | 2546 fps | 98.8% |
| Ramshot Wild Boar | <<locked>> | 88% | 55,085 psi | 88% | 2562 fps | 99.9% |
| Ramshot X-Terminator | <<locked>> | 84% | 53,069 psi | 85% | 2484 fps | 99.7% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,578 psi | 57% | 1549 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 55,027 psi | 88% | 2510 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 55,448 psi | 89% | 2549 fps | 98.1% |
| ReloadSwiss RS 52 | <<locked>> | 90% | 54,128 psi | 87% | 2621 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 53,577 psi | 86% | 2651 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 49,980 psi | 80% | 2579 fps | 98.8% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 50,691 psi | 81% | 2602 fps | 98.5% |
| Rottweil R 901 | <<locked>> | 88% | 56,086 psi | 90% | 2503 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 55,419 psi | 89% | 2516 fps | 100% |
| Rottweil R 903 | <<locked>> | 96% | 53,374 psi | 86% | 2546 fps | 100% |
| Rottweil R 907 | <<locked>> | 98% | 54,143 psi | 87% | 2520 fps | 96.7% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 55,071 psi | 88% | 2546 fps | 98.6% |
| Shooters World Match Rifle | <<locked>> | 90% | 55,709 psi | 89% | 2549 fps | 100% |
| Shooters World Precision | <<locked>> | 94% | 56,159 psi | 90% | 2546 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 52,634 psi | 84% | 2530 fps | 97.3% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 54,766 psi | 88% | 2484 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 96% | 55,158 psi | 88% | 2602 fps | 99.9% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 54,607 psi | 88% | 2457 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 53,940 psi | 86% | 2523 fps | 98.9% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 54,534 psi | 87% | 2546 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 88% | 53,563 psi | 86% | 2425 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 53,258 psi | 85% | 2421 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 55,782 psi | 89% | 2503 fps | 97.4% |
| Somchem S321 | <<locked>> | 84% | 53,011 psi | 85% | 2513 fps | 100% |
| Somchem S335 | <<locked>> | 90% | 55,999 psi | 90% | 2464 fps | 100% |
| Somchem S341 | <<locked>> | 88% | 53,403 psi | 86% | 2516 fps | 99.8% |
| Somchem S355 | <<locked>> | 96% | 53,838 psi | 86% | 2543 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 44,686 psi | 72% | 2507 fps | 100% |
| Unknown powderᴾ | <<locked>> | 100% | 54,839 psi | 88% | 2605 fps | 99% |
| Vihtavuori N130 | <<locked>> | 84% | 53,476 psi | 86% | 2395 fps | 100% |
| Vihtavuori N133 | <<locked>> | 88% | 53,650 psi | 86% | 2411 fps | 100% |
| Vihtavuori N135 | <<locked>> | 92% | 54,723 psi | 88% | 2484 fps | 100% |
| Vihtavuori N140 | <<locked>> | 92% | 55,927 psi | 90% | 2503 fps | 100% |
| Vihtavuori N150 | <<locked>> | 98% | 55,492 psi | 89% | 2526 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 52,707 psi | 85% | 2549 fps | 99.1% |
| Vihtavuori N530 | <<locked>> | 88% | 56,057 psi | 90% | 2526 fps | 100% |
| Vihtavuori N540 | <<locked>> | 92% | 53,954 psi | 87% | 2503 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 51,677 psi | 83% | 2556 fps | 98.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 37,434 psi | 60% | 2388 fps | 97.2% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 53,403 psi | 86% | 2536 fps | 100% |
| Winchester 748 | <<locked>> | 86% | 56,188 psi | 90% | 2579 fps | 100% |
| Winchester 760 | <<locked>> | 98% | 55,724 psi | 89% | 2631 fps | 97.7% |
| Winchester StaBALL Match | <<locked>> | 84% | 55,941 psi | 90% | 2575 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% | 44,788 psi | 72% | 2313 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 48,820 psi | 78% | 2415 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 37,347 psi | 60% | 2247 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 42,525 psi | 68% | 2365 fps | 100% |
| Accurate 2700 | <<locked>> | 92% | 49,371 psi | 79% | 2405 fps | 95.3% |
| Accurate 4064 | <<locked>> | 80% | 35,317 psi | 57% | 2238 fps | 99.8% |
| Accurate 4350 | <<locked>> | 88% | 33,431 psi | 54% | 2257 fps | 95% |
| Accurate LT-30 | <<locked>> | 80% | 52,997 psi | 85% | 2382 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 41,147 psi | 66% | 2336 fps | 98.4% |
| ADI AR 2208 | <<locked>> | 80% | 35,128 psi | 56% | 2205 fps | 96.1% |
| ADI Benchmark 8208 | <<locked>> | 80% | 43,178 psi | 69% | 2346 fps | 99.5% |
| Alliant AR-Comp | <<locked>> | 80% | 42,902 psi | 69% | 2339 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 50,256 psi | 81% | 2526 fps | 99.9% |
| Alliant Power Pro 2000-MR | 63.2 gr | 80% | 37,173 psi | 60% | 2352 fps | 96.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 34,476 psi | 55% | 2224 fps | 97.7% |
| Alliant Reloder-10x | <<locked>> | 80% | 50,618 psi | 81% | 2398 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 36,999 psi | 59% | 2277 fps | 97% |
| Alliant Reloder-16 | <<locked>> | 88% | 34,461 psi | 55% | 2270 fps | 95.2% |
| Alliant Reloder-17 | <<locked>> | 82% | 31,691 psi | 51% | 2238 fps | 96% |
| Alliant Reloder-23 | <<locked>> | 96% | 31,024 psi | 50% | 2221 fps | 95.4% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 52,069 psi | 83% | 2382 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 40,045 psi | 64% | 2336 fps | 97.2% |
| Bofors RP3 | <<locked>> | 80% | 33,837 psi | 54% | 2224 fps | 97.7% |
| Bofors RP7 | <<locked>> | 94% | 47,892 psi | 77% | 2428 fps | 95.3% |
| Hodgdon Benchmark | <<locked>> | 80% | 45,107 psi | 72% | 2339 fps | 99.9% |
| Hodgdon BL-C2 | <<locked>> | 80% | 41,597 psi | 67% | 2365 fps | 99.6% |
| Hodgdon CFE223 | <<locked>> | 80% | 45,730 psi | 73% | 2487 fps | 98.9% |
| Hodgdon H322 | <<locked>> | 80% | 45,876 psi | 74% | 2382 fps | 100% |
| Hodgdon H380 | <<locked>> | 82% | 37,115 psi | 60% | 2274 fps | 95.6% |
| Hodgdon H414 | <<locked>> | 92% | 45,542 psi | 73% | 2477 fps | 95.6% |
| Hodgdon H4350 | <<locked>> | 98% | 49,864 psi | 80% | 2497 fps | 95% |
| Hodgdon H4895 | <<locked>> | 80% | 41,510 psi | 67% | 2346 fps | 98.9% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 29,501 psi | 47% | 2133 fps | 95.1% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 35,201 psi | 56% | 2274 fps | 98% |
| Hodgdon Superformance | <<locked>> | 96% | 47,688 psi | 76% | 2526 fps | 95.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,136 psi | 42% | 1348 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 37,043 psi | 59% | 2251 fps | 97.9% |
| IMR 3031 | <<locked>> | 80% | 37,550 psi | 60% | 2290 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 34,345 psi | 55% | 2182 fps | 96.2% |
| IMR 4166 Enduron | <<locked>> | 90% | 46,456 psi | 74% | 2379 fps | 95.6% |
| IMR 4198 | <<locked>> | 80% | 50,908 psi | 82% | 2362 fps | 100% |
| IMR 4350 | <<locked>> | 98% | 47,747 psi | 77% | 2451 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 92% | 46,934 psi | 75% | 2415 fps | 95.6% |
| IMR 4831 | <<locked>> | 92% | 33,228 psi | 53% | 2238 fps | 95% |
| IMR 4895 | <<locked>> | 80% | 37,884 psi | 61% | 2303 fps | 97.8% |
| IMR 8208 XBR | <<locked>> | 80% | 43,178 psi | 69% | 2346 fps | 99.5% |
| Lovex D073.4 | <<locked>> | 80% | 50,821 psi | 81% | 2444 fps | 100% |
| Lovex D073.5 | <<locked>> | 80% | 48,515 psi | 78% | 2421 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 39,813 psi | 64% | 2320 fps | 99.9% |
| Lovex S060 | <<locked>> | 80% | 41,626 psi | 67% | 2283 fps | 98.5% |
| Lovex S062 | <<locked>> | 80% | 36,608 psi | 59% | 2238 fps | 98.6% |
| Lovex S065 | <<locked>> | 90% | 40,814 psi | 65% | 2320 fps | 95.7% |
| Lovex S070 | <<locked>> | 94% | 43,729 psi | 70% | 2388 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 40,364 psi | 65% | 2297 fps | 99.2% |
| Norma 202 | <<locked>> | 80% | 40,640 psi | 65% | 2310 fps | 100% |
| Norma 203B | <<locked>> | 80% | 36,390 psi | 58% | 2267 fps | 97.4% |
| Norma URP | <<locked>> | 88% | 34,214 psi | 55% | 2264 fps | 95% |
| Ramshot Big Game | <<locked>> | 80% | 35,766 psi | 57% | 2277 fps | 96.9% |
| Ramshot Hunter | <<locked>> | 94% | 40,567 psi | 65% | 2395 fps | 95% |
| Ramshot TAC | <<locked>> | 80% | 43,105 psi | 69% | 2349 fps | 96.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 42,351 psi | 68% | 2369 fps | 98.6% |
| Ramshot X-Terminator | <<locked>> | 80% | 46,601 psi | 75% | 2388 fps | 99.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,455 psi | 42% | 1385 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 48,486 psi | 78% | 2421 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 42,830 psi | 69% | 2356 fps | 95.4% |
| ReloadSwiss RS 52 | 61.3 gr | 80% | 38,421 psi | 62% | 2365 fps | 97.4% |
| ReloadSwiss RS 60 | 62.2 gr | 80% | 31,560 psi | 51% | 2244 fps | 98.4% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 35,636 psi | 57% | 2323 fps | 95.3% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 38,827 psi | 62% | 2382 fps | 95.3% |
| Rottweil R 901 | <<locked>> | 80% | 44,396 psi | 71% | 2339 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 38,493 psi | 62% | 2254 fps | 98.9% |
| Rottweil R 903 | <<locked>> | 80% | 31,850 psi | 51% | 2175 fps | 96.7% |
| Rottweil R 907 | <<locked>> | 94% | 47,892 psi | 77% | 2428 fps | 95.3% |
| Shooters World Long Rifle | <<locked>> | 90% | 40,814 psi | 65% | 2320 fps | 95.7% |
| Shooters World Match Rifle | <<locked>> | 80% | 39,813 psi | 64% | 2320 fps | 99.9% |
| Shooters World Precision | <<locked>> | 80% | 36,608 psi | 59% | 2238 fps | 98.6% |
| Shooters World SW4350 | <<locked>> | 94% | 43,729 psi | 70% | 2388 fps | 95.3% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 51,198 psi | 82% | 2438 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 32,895 psi | 53% | 2218 fps | 96% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 51,358 psi | 82% | 2418 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 41,104 psi | 66% | 2320 fps | 96.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 39,755 psi | 64% | 2310 fps | 98.1% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 41,959 psi | 67% | 2260 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 34,650 psi | 56% | 2142 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 45,861 psi | 74% | 2365 fps | 95.5% |
| Somchem S321 | <<locked>> | 80% | 46,398 psi | 74% | 2415 fps | 99.9% |
| Somchem S335 | <<locked>> | 80% | 41,423 psi | 66% | 2260 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 40,785 psi | 65% | 2323 fps | 98.3% |
| Somchem S355 | <<locked>> | 80% | 32,793 psi | 53% | 2182 fps | 96.7% |
| Somchem S365 | <<locked>> | 84% | 26,948 psi | 43% | 2119 fps | 95.5% |
| Unknown powder | <<locked>> | 88% | 37,347 psi | 60% | 2316 fps | 95.3% |
| Vihtavuori N130 | <<locked>> | 80% | 47,442 psi | 76% | 2316 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 42,163 psi | 68% | 2257 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 37,666 psi | 60% | 2244 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 38,406 psi | 62% | 2251 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 31,169 psi | 50% | 2126 fps | 97.6% |
| Vihtavuori N160 | <<locked>> | 88% | 35,810 psi | 57% | 2264 fps | 95.5% |
| Vihtavuori N530 | <<locked>> | 80% | 43,250 psi | 69% | 2343 fps | 99.6% |
| Vihtavuori N540 | <<locked>> | 80% | 36,840 psi | 59% | 2241 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 88% | 35,056 psi | 56% | 2267 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 96% | 33,011 psi | 53% | 2293 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 29,617 psi | 47% | 2103 fps | 95.2% |
| Winchester 748 | <<locked>> | 80% | 45,701 psi | 73% | 2434 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 45,542 psi | 73% | 2477 fps | 95.6% |
| Winchester StaBALL Match | <<locked>> | 80% | 48,501 psi | 78% | 2474 fps | 99.7% |
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 117 powders for .375 H&H Mag. loaded with the .375 | 285gr | Speer Grand Slam. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,677 fps; across all powders the maximum-charge window runs from 1,512 fps to 2,677 fps. Accurate 3100 gives the best case fill at 100 %, and 117 of the 117 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (430 MPa), the top charges use 50–90 %, leaving at least 10 % headroom. The 285.0 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. ReloadSwiss RS 60, Alliant Power Pro 2000-MR, ReloadSwiss RS 52 rank at the top here: for .375 H&H Mag. with the .375 | 285gr | Speer Grand Slam they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 3100, ADI AR 2209, Alliant Reloder-19 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.